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  • Diagnostic and prognostic value of red blood cell distribution width in sepsis: a narrative review
    Clin. Biochem. (IF 2.43) Pub Date : 2020-01-11
    Zhi-De Hu; Giuseppe Lippi; Martina Montagnana

    Previous studies showed that red blood cell distribution width (RDW) can be used as a prognostic and diagnostic index in various non-hematological diseases, including severe infections and sepsis. Here, we provide a narrative review to summarize the findings of available studies investigating the relationship between RDW and sepsis. Current evidence supports that increased RDW on admission, both in adults and neonates, is associated with unfavorable outcomes on the short- and long-term. In patients with suspected sepsis, RDW has modest value for predicting positive blood culture. Accordingly, its diagnostic value for sepsis is limited. Dynamic changes of RDW are also associated with outcome of sepsis. Taken together, these results suggest that RDW could be used as a prognostic index in septic patients.

  • Kallikrein-related peptidases protein expression in lymphoid tissues suggests potential implications in immune response
    Clin. Biochem. (IF 2.43) Pub Date : 2020-01-02
    Panagiota S. Filippou; Annie H. Ren; Antoninus Soosaipillai; Roaa Safar; Ioannis Prassas; Eleftherios P. Diamandis; James R. Conner

    Objectives Kallikrein-related peptidases (KLKs) are a subgroup of 15 secreted chymotrypsin- and trypsin-like serine proteases that have been reported to possess novel functions in innate immunity and inflammation. Since the potential role of KLKs in immunity has not been studied in detail at the protein level, we examined the expression pattern of 12 members of the KLK family in immune-related tissues. Design & Methods Protein expression in tissue extracts was evaluated using immunoassays (ELISA). Immunohistochemistry (IHC) was performed on representative sections of tonsil and lymph nodes to determine the cellular localization of the KLK family members. Results ELISA profiling of KLK3-KLK15 (except KLK12) revealed higher protein levels in the tonsil, compared to the lymph nodes and spleen. Relatively high protein levels in the tonsil were observed for KLK7, KLK9, KLK10 and KLK13. Expression of these KLKs was significantly lower in lymph nodes and spleen. IHC analysis in tonsil unveiled that KLK9 and KLK10 were differentially expressed in lymphoid cells. KLK9 was strongly expressed in the germinal center of lymphoid follicles where activated B-cells reside, whereas KLK10 was expressed in the follicular dendritic cells (FDCs) that are vital for maintaining the cycle of B cell maturation. Conclusion Overall, our study revealed the possible implications of KLK expression and regulation in the immune cells of lymphoid tissues.

  • Superiority of high sensitivity cardiac troponin T vs. I for long-term prognostic value in patients with chest pain; Data from the Akershus Cardiac Examination (ACE) 3 Study
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-31
    Sjur H. Tveit; Peder L. Myhre; Nils Jakob S. Hoff; Tri M. Le; Ingebjørg Seljeflot; Ragnhild Røysland; Arne Didrik Høiseth; Helge Røsjø; Torbjørn Omland

    Background Cardiac troponins (cTn) are essential in the diagnostic assessment of non-ST-segment-elevation acute coronary syndrome (NSTE-ACS). Elevated concentrations of cTnT and cTnI predict cardiovascular events in non-acute settings, but the individual troponin isotype association with long-term mortality in patients with suspected unstable angina pectoris (UAP) is less clear. Methods Patients hospitalized with chest pain between June 2009 and December 2010 were included in the Akershus Cardiac Examination 3 Study and followed for median 6.6 (IQR 6.2-7.1) years. The index diagnosis was adjudicated by an independent committee as NSTE-myocardial infarction (NSTEMI), UAP or non-ACS. Blood samples were collected within 24 hours of admission and analyzed with high sensitivity assays for cTnT (hs-cTnT, Roche) and cTnI (hs-cTnI, Singulex). Results Of 402 patients included, 74 (18%) were classified as NSTEMI, 88 (22%) UAP and 240 (60%) non-ACS. hs-cTnI concentrations were detectable in all patients (median 3 [IQR 1-11] ng/L), while hs-cTnT concentrations were above the level of blank in 205 (51%) (median 3 [IQR 3-16] ng/L). In patients with UAP, both log2-transformed hs-cTnT and hs-cTnI were associated with all-cause mortality in analyses that adjusted for other risk factors: HR 2.40 [95% CI 1.75-3.30], p<0.001 and HR 1.44 [1.14-1.81], p=0.002. There were no significant sex-dependent differences in the association between hs-cTnT or hs-cTnI and outcome. Time dependent receiver-operating characteristics area under the curve was 0.85 (95% CI 0.79-0.92) for hs-cTnT and 0.74 (0.64-0.84) for hs-cTnI, p=0.008 for difference between values. Conclusions Higher concentrations of hs-cTnT and hs-cTnI were both associated with all-cause mortality in patients with UAP, but the association with outcome was stronger for hs-cTnT than for hs-cTnI.

  • A review of biomarker utilization in the diagnosis and management of acute pancreatitis reveals amylase ordering is favored in patients requiring laparoscopic cholecystectomy
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-31
    Cameron Furey; James Buxbaum; Allison B. Chambliss

    Background Despite widespread recommendations to favor lipase over amylase in the diagnosis and management of acute pancreatitis, many routine hospital laboratories still offer amylase testing. This study sought to evaluate and compare ordering patterns of amylase and lipase in patients with acute pancreatitis. Methods We analyzed 438 patients with acute pancreatitis admitted to our hospital. Data collection included pancreatitis etiology and management as well as biochemical profiles of amylase and lipase. We compared serial ordering patterns, degree of biomarker elevation, and normalization kinetics. Results All patients had at least one lipase ordered during their admission, and only 51 patients (12%) had at least one amylase ordered. On average, lipase was elevated 5 times higher above its respective upper reference limit than amylase at admission. Pancreatitis etiology was skewed toward gallstones in the amylase group as compared to the lipase only group (69% vs. 43%), and surgical patients (laparoscopic cholecystectomy) were more likely to have amylase ordered and/or trended. Conclusions Amylase measurement was not necessary in the diagnosis and management of 88% of patients with acute pancreatitis. Of patients for whom amylase was ordered, it was common for these patients to be those referred to surgical procedures, possibly because amylase normalization may be documented faster than that of lipase.

  • Characteristics of bone turnover markers in women with gestational diabetes mellitus
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-30
    Jing Zhang; Yiduo Zhang; Jing Wang; Fan Yu

    Background Bone turnover markers (BTMs) can be applied to the assessment of bone formation and bone resorption activity. The aim of this study was to investigate the changes in BTMs in women with gestational diabetes mellitus (GDM). Methods One hundred and five women with gestational diabetes mellitus defined as the GDM group and 46 healthy pregnant women with normal glucose tolerance selected as the control group were enrolled in this study. Serum samples were collected during regular obstetric examinations and the serum levels of total procollagen type 1 N-terminal propeptide (P1NP), N-terminal midfragment of osteocalcin (N-MID), and β-C-terminal telopeptide of type 1 collagen (β-CTX) were measured. An independent-sample t-test, the Mann–Whitney U test, and a Pearson correlation analysis were performed for data analyses. Results Serum β-CTX levels in the GDM group were significantly higher than those in the control group (296.00 [235.00–369.00] pg/mL vs. 218.5 [165.25–292.50] pg/mL, p<0.05), while P1NP and N-MID levels did not differ between the two groups. The Pearson correlation analysis revealed that β-CTX level was correlated with blood glucose level. Conclusions The difference in β-CTX levels indicated that bone resorption in patients with GDM diabetes was higher than that in pregnant women with normal glucose tolerance. No obvious differences in bone formation markers P1NP and N-MID were found between the two groups.

  • Inappropriate repeat testing of complete blood count (CBC) and electrolyte panels in inpatients from Alberta, Canada
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-28
    Vijay Kandalam; Cheryl K. Lau; Maggie Guo; Irene Ma; Christopher Naugler

    Introduction The avoidance of repeat chemistry testing such as Complete Blood Count (CBC) and Electrolyte Panel (EP) on clinically stable patients was identified as important utilization goals by Choosing Wisely Canada. The purpose of this study was to assess the volume of overutilization of CBC and EP in an inpatient setting in Alberta, Canada, and provide an estimated cost assessment of unnecessary testing. Methods: The total laboratory testing volumes of two common test panels were collected retrospectively for one-year from January to December 2018. Data was collected on test panels performed in an emergency room (ER) and inpatient setting from three separate Laboratory Information Systems covering the provincial population in Alberta, Canada. Total initial test panel instances, total repeated panels, repeated panels that were previously normal or abnormal, and estimated costs were examined. Cost assessment was completed based on Reference Median Cost (RMC) analysis for each of these two common test panels. Results: During the study period, 2,020,467 (CBC) and 1,455,983 (EP) initial test panel instances were recorded, of which 67.7% and 73.5% were repeated for the CBC and EP, respectively. There was a higher proportion of EP repeated inappropriately (previously normal; 35.6%) compared to CBCs (5.4%). The cost to the province for inappropriately repeating CBC and EP were estimated to be RMC $0.52 million and RMC $1.90 million CAD, respectively. Conclusion: Results from this study can assist policy makers in implementing utilization management initiatives and update clinical practice guidelines to reduce costs to healthcare without compromising patient care.

  • Identification of gamma heavy chain disease using MALDI-TOF mass spectrometry
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-26
    Katie L. Thoren; Marion Eveillard; Patrick Chan; Sital Doddi; Sun Cho; Kazunori Murata

    We describe the use of MALDI-TOF mass spectrometry in the analysis of a suspected case of gamma heavy chain disease. The patient had an abnormal serum immunofixation result where a monoclonal gamma heavy chain band was present without a corresponding light chain. Analysis by MALDI-TOF mass spectrometry revealed large peaks in the spectrum following IgG-specific purification. The m/z values of the peaks were outside the expected range for normal heavy chains or light chains. Corresponding peaks were not present in mass spectra of the kappa- or lambda-specific purifications. MALDI-TOF MS confirmed the presence of a truncated heavy chain without associated light chains. This case report demonstrates the value of mass spectrometry in interpreting challenging cases such as the identification of heavy chain disease.

  • CALIPER Paediatric Reference Intervals for the Urea Creatinine Ratio in Healthy Children & Adolescents
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-12
    Mary Kathryn Bohn; Victoria Higgins; Khosrow Adeli

    Background The urea creatinine ratio (UCR) is important in the clinical assessment of several medical conditions, including acute kidney injury and gastrointestinal bleeding. However, accurate and robust paediatric reference intervals (RIs) for this ratio have not been well established. Here, we determined age- and sex-specific discrete and continuous RIs for UCR in the Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER) cohort of healthy children and adolescents for the first time. Methods UCR was calculated for approximately 1030 CALIPER participants using retrospective urea and creatinine (both Jaffe and enzymatic methods) normative data. Partitions were determined using the Harris & Boyd statistical method. Discrete RIs were established in accordance with Clinical Laboratory Standards Institute (CLSI) guidelines. Continuous RIs were established using nonparametric quantile regression. Results Several age- and sex-specific partitions were necessary to capture dynamic physiological trends associated with this ratio throughout childhood and adolescence, highlighting the benefit of continuous RI establishment. Established UCR RIs also demonstrated marked differences between Jaffe and enzymatic assay methods. Conclusion Our results clearly demonstrate the critical need for RI stratification by important covariates such as age, sex, and creatinine assay methodology for paediatric UCR test result interpretation. These data contribute to our understanding of normative UCR values in childhood and adolescence and can be expected to improve paediatric test result interpretation in clinical laboratories that report this ratio.

  • The Challenge that Chlorine Presented during the Development of a Benzodiazepine Assay
    Clin. Biochem. (IF 2.43) Pub Date : 2019-12-04
    Richard G. Lahr, Paul J. Jannetto, Loralie J. Langman

    During the routine validation of a benzodiazepine method (performed on a Liquid Chromatography - Tandem Mass Spectrometer), it was noted that lorazepam, triazolam, and α-hydroxytriazolam showed a quadratic shift/bias in the calibration curve, particularly at high concentrations. The ultimate cause of this bias was determined to be due to the natural presence of chlorine (Cl) isotopes (35Cl and 37Cl) in these benzodiazepines. The presence of the heavy (37Cl) isoforms of Cl resulted in the analyte’s mass being the same as the internal standard which, in turn, caused the internal standard to appear “falsely increased”, thus skewing the calibration curve. One solution to this potential issue was to take advantage of this natural phenomenon and use the Cl heavy isoforms of the respectively labeled internal standards.

  • Emerging biomarkers for cardiac arrhythmias
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-28
    Angelika Hammerer-Lercher, Mehdi Namdar, Nicolas Vuilleumier

    Cardiac arrhythmias are associated with substantial morbidity and mortality. Recent advances in the pathophysiological understanding of cardiac arrhythmia indicate that inflammation, fibrosis, and even autoimmune mechanisms could facilitate the development of arrhythmias by interfering either with fibroblast activation-related electrical remodeling or with the function of different cardiac ion channels, leading to the emerging concepts of autoimmune and inflammatory channelopathies. In this descriptive review, we considered recent data of the literature focusing on biomarkers reflecting the degree of inflammation, myocardial stretch, fibrosis and sustained B-cell activation as potential additional diagnostic, risk stratification tools and potential therapeutic targets in cardiac arrhythmia.

  • Reduction of AHI1 in the serum of Taiwanese with probable Alzheimer’s disease
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-28
    Jau-Jiuan Sheu, Li-Yu Yang, Monika Renuka Sanotra, Sen-Te Wang, Hsien-Tsung Lu, Rachel Sook Yee Kam, I-Uen Hsu, Shu-Huei Kao, Ching-Kuo Lee, Jonathan Chang-Cheng Shieh, Yung-Feng Lin

    Objective The development of blood-based biomarkers for early diagnosis and treatment of Alzheimer’s disease (AD) is desirable. In AD model mouse brain and neuronal cells, Abelson helper integration site-1 (AHI1) protein is reduced. AHI1 facilitates intracellular amyloid precursor protein (APP) translocation to inhibit amyloidogenic pathology of AD, and thus may be an AD biomarker. Methods This study was conducted among 32 AD patients and 54 healthy control (HC) subjects. AHI1-related protein levels from initially collected serum samples in each group were screened using Western blotting. The protein concentrations of AHI1 and amyloid-β (Aβ), peptide(s) derived from APP, from all serum samples were analyzed using ELISA. Results In AD serum, AHI1 and a large truncated C-terminal APP fragment were significantly reduced. The average concentrations of serum AHI1 and Aβ in AD were significantly lower than those in HC. Notably, AHI1 concentration in HC serum was decreased in an age-dependent manner, while it was consistently low in AD serum and had no correlation with Aβ or mini-mental state examination score. The receiver operating characteristic analysis on all subjects demonstrated an area under curve (AUC) value of 0.7 for AHI1 on AD diagnosis, while the AUC increased to 0.82 on the subjects younger than 77 years old, suggesting a good diagnostic performance of serum AHI1 for AD especially at relatively young age. Conclusion An early event of AHI1 reduction in the body of AD patients was observed. Serum AHI1 may be valuable for early diagnosis of AD.

  • Gender-Specific Reference Values for High-Sensitivity Cardiac Troponin T and I in Well-Phenotyped Healthy Individuals and Validity of High-Sensitivity Assay Designation
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-28
    Evangelos Giannitsis, Matthias Mueller-Hennessen, Tanja Zeller, Anna Schuebler, Matthias Aurich, Moritz Bieneram, Mehrshad Vafaie, Kiril Stoyanov, Marco Ochs, Johannes Riffel, Derliz Mereles, Stefan Blankenberg, Hugo A. Katus

    Objective To determine gender-specific reference limits of high-sensitivity (hs) cardiac troponins (cTn) and validity of hs assay designation for both genders. Methods After screening with a questionnaire, 827 presumably healthy individuals were further selected based on clinical criteria (n=740), clinical criteria plus cardiac imaging including stress magnetic resonance imaging or stress echocardiography (n=726), and extended cardio-pulmonary parameters (n=626). Blood samples were measured with hs-cTnT (Roche Diagnostics) on a cobas e602 analyzer as well as hs-cTnI (Abbott Diagnostics) on an ARCHITECTi2000SR. The impact of health definition, statistical methods, instrument selection and limit of detection (LoD) on overall and gender-specific 99th percentiles was assessed. Results Median age was 56 years (50.9% female) for the total study cohort. 99th percentiles for females and males ranged between 13.1-13.3 ng/L and 16.8-19.9 ng/L for hs-cTnT as well as 10.3-12.5 ng/L and 27.4-29.7 ng/L for hs-cTnI depending on health definition. Utilization of stricter health definition criteria reduced the difference of the gender-specific 99th percentiles between males and females for hs-cTnT to 3.7 ng/L (males 16.8 ng/L, females 13.1 ng/L), whereas the difference rather increased for hs-cTnI to 19.4 ng/L (males 29.7 ng/L, females 10.3 ng/L). Values >LoD could be measured in the majority of males and females using hs-TnT (81.4-83.3% and 96.5-96.9%, respectively). In contrast, values >LoD could not be observed in the majority of females using hs-cTnI (38.4-41.1%). Conclusions In a well-phenotyped healthy cohort, reference values for hs-cTnT were slightly higher, whereas hs-cTnI cut-offs were considerably lower than previously observed. Gender differences were more pronounced in hs-cTnI than in hs-cTnT and were further reduced for hs-cTnT by application of stricter health definition criteria. Contrary to hs-cTnI, hs-cTnT fulfilled criteria for hs designation for both genders.

  • Identification of germline pathogenic variants in DNA damage repair genes by a next-generation sequencing multigene panel in BRCAX patients
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-28
    Marta Rodríguez-Balada, Bàrbara Roig, Mireia Melé, Cinta Albacar, Sara Serrano, Mònica Salvat, Montserrat Querol, Joan Borràs, Lourdes Martorell, Josep Gumà

    Background Approximately 5-10% of breast carcinomas have been related to hereditary conditions and are attributable to pathogenic variants in the BRCA1 and BRCA2 genes, which is referred to as hereditary breast and ovarian cancer (HBOC) syndrome. The inclusion of additional genes that can be related to HBOC syndrome is under intense evaluation due to the high proportion of patients with HBOC criteria who do not present pathogenic mutations in BRCA genes, named BRCAX, despite having high clinical suspicion of hereditary cancer. The main aim is to identify new potentially pathogenic gene variants that may contribute to HBOC to improve the efficiency of routine diagnostic tests in this hereditary condition. Methods A retrospective cohort of 77 HBOC BRCAX patients was analyzed by next-generation sequencing using a targeted multigene panel composed of 25 genes related to hereditary cancer and deficiencies in DNA repair pathways. Results We found 9 variants in 7 different genes, which were confirmed by automated sequencing. Six variants were classified as pathogenic or likely pathogenic. Three of them were located in the PALB2 gene, one in the BRIP1 gene, one in the BARD1 gene and 1 in the RAD50 gene. In addition, three variants of uncertain significance (VUS) were detected in the TP53, CHEK2, and CDH1 genes. Conclusions We identified that 8% of BRCAX patients were carriers of pathogenic variants in genes other than BRCA1 and BRCA2. Therefore, wide gene panels, including clinically actionable genes, should be routinely used in the screening of HBOC in our population. We observed differences from other studies in the prevalence of mutated genes, most likely due to differences in the selection criteria of the probands and in the population analyzed. The high incidence of deleterious variant detection in PALB2 supports its significant role in breast cancer susceptibility and reinforces its inclusion in the HBOC genetic diagnostic process.

  • Automatic laboratory interventions to unmask and treat hypomagnesemia in the Emergency Department
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-28
    Maria Salinas, Emilio Flores, Maite López-Garrigós, Carmen Puche, Carlos Leiva-Salinas

    Introduction The significance of hypomagnesemia and the need for treatment are under-recognized in clinical practice. Our objective was to design, establish, and test two interventions to screen for patients with hypomagnesemia and increase the rate of treatment of hypomagnesemia in the emergency department (ED). Material and Methods A prospective two-year study was conducted. The Laboratory Information System was set to automatically order plasma magnesium in ED patients with plasma calcium <7.5mg/dL (1.9mmol/L) and/or plasma potassium <2.5mEq/L (2.5mmol/L). We counted the number of identified cases of hypomagnesemia, and calculated the total economic cost per identified patient. The study had three periods “Central lab” “Stat lab” and “Stat lab with comment” according to the availability to measure plasma magnesium levels in the stat laboratory and the inclusion of an automatic comment in the laboratory report in cases of hypomagnesemia. We retrospectively reviewed the medical records of patients with magnesium<1.5 mg/dL (0.6 mmol/L), to investigate whether they have been appropriately treated. Results A total of 410 plasma magnesium were measured due to our intervention; 179 due to hypokalemia and 231 due to hypocalcemia. Two hundred thirty (56.1%) of 410 showed hypomagnesemia. Each detected case resulted in reagent cost of 0.7$, when prompted by hypocalcemia, and 0.6$ when prompted by hypokalemia. The rate of patients with hypomagnesemia that were appropriately treated increased from 15% to 75% along the study period. Conclusions Our strategies successfully identified patients with hypomagnesemia in the ED at a very affordable cost, and increased the percentage of patients with hypomagnesemia that received treatment.

  • An isotope dilution LC-MS/MS based candidate reference method for the quantification of cyclosporine A, tacrolimus, sirolimus and everolimus in human whole blood
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-23
    Judith Taibon, Milou van Rooij, Rupert Schmid, Neeraj Singh, Eva Albrecht, Jo Anne Wright, Christian Geletneky, Carina Schuster, Sophie Mörlein, Michael Vogeser, Christoph Seger, Stephan Pongratz, Uwe Kobold

    An isotope dilution LC-MS/MS based candidate reference measurement procedure for the quantification of cyclosporine A, tacrolimus, sirolimus and everolimus in human whole blood is presented to be used for evaluation and standardization of routine assays applied for therapeutic drug monitoring. The assay allows baseline separation of the four immunosuppressive drugs within a total runtime of 9 minutes using a C4 reversed phase column. Sample preparation is based on protein precipitation with zinc sulphate followed by purification with solid phase extraction. Reference materials used in this reference measurement procedure were characterized by qNMR and an absolute content of analytes calculated to guarantee traceability to SI units. As internal standards the corresponding deuterated and 13C-labeled analytes were used. The method allows the measurement of cyclosporine A in the range of 5 ng/mL to 2100 ng/mL; tacrolimus, sirolimus and everolimus were analysed in the range of 0.25 ng/mL to 50 ng/mL. Imprecision for inter-day measurements were found to be ≤ 3.5 % for cyclosporine A and ≤ 4.4 % for tacrolimus, sirolimus and everolimus. Accuracy was found to be within 101 % and 108 % for cyclosporine A and between 95% and 104 % for the macrolide compounds. The uncertainty was evaluated according to the GUM. Expanded measurement uncertainties were found to be ≤ 7.2 % for cyclosporine A, ≤ 6.8 % for tacrolimus, ≤ 9.0 % for sirolimus and ≤ 8.9 % for everolimus (k = 2).

  • Establishing reference intervals of coagulation indices based on the ACL Top 700 system for children in Southwestern Fujian, China
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-23
    Huifen Zhang, Jiming Li, Haichen Chen, Xingdong Wu

    Background Till date, China has not issued industry standards for reference intervals (RIs) of pediatric blood coagulation indices. Here, we evaluated changes in the coagulation indices in the venous blood of healthy children aged 29 days to 12 years derived using the ACL Top 700 system and established appropriate RIs. Methods We analyzed venous blood from 1770 healthy children for five coagulation indices. RIs were established according to the Clinical and Laboratory Standards Institute C28-A3c guideline. Results The coagulation indices were grouped by age. For prothrombin time (PT) and international normalization ratio (INR), the RIs of infants and toddlers were identical; preschool children had the same RI as school-age children. Pediatric RIs for PT and INR were slightly lower than those for adults. The RIs of activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB) in childhood were divided into two groups by age (1 month to 1 year and 1–12 years). The RI of APTT in infants was the widest; the overall level of FIB in infants was the lowest; children's APTT and FIB RIs were lower than those of adults. The pattern of TT values and RI trends in childhood were similar to those of APTT. Conclusions There were minor changes in the RIs of coagulation indices for children. The RIs of PT, INR, APTT, TT, and FIB must be grouped by age. The RIs of coagulation indices for children were different from those for adults; therefore, establishing separate RIs for children is necessary.

  • Plasma proteomics-based identification of novel biomarkers in early gastric cancer
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-22
    Bin Zhou, Zhe Zhou, Yuling Chen, Haiteng Deng, Yunlong Cai, Xiaolong Rao, Yuxin Yin, Long Rong

    Background Identification and treatment in the early stage can significantly improve the prognosis of gastric cancer (GC). However, to date, there is still no ideal biomarker that can be used for the screening of early stage GC (EGC). The proteomics supported by mass spectrometry offers more possibilities for discovering tumor biomarkers. The aim of this study was to explore candidate protein biomarkers for EGC screening with mass spectrometry and bioinformatics technology. Methods Plasma samples were collected from 15 EGC patients and 15 healthy controls. After a selective immune-depletion to remove high abundance proteins, plasma samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with the tandem mass tags (TMT) labeling. Results A total of 2040 proteins were identified, and 11 proteins were found to be differentially expressed. The results of the logistic regression model and orthogonal signal correction-partial least squares discriminant analysis (OPLS-DA) model showed that the changed proteins identified by plasma proteomics could help distinguish EGC patients from healthy controls. Conclusion The proteins identified by plasma proteomics using LC-MS/MS combined with TMT labeling could help distinguish EGC from healthy controls.

  • Very high levels of PSA in patients with cardiogenic shock: report of four clinical cases
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-22
    Esther Fernández-Galán, Josep M. Augé, Rafael Molina, Xavier Filella

    Prostate-specific antigen (PSA) is the tumor marker most widely used in conjunction with digital rectal examination (DRE) for the early detection of prostate cancer (PCa). Due to its limitations, especially the high rate of false positive (FP) results, PSA screening of transplant candidates is a controversial issue. Moreover, obtaining a FP result in the PCa screening of heart transplant candidates may lead to potentially harmful effects. Although most of the factors that may cause PSA FP results are well known, FP results related to cardiogenic shock, a common indication for heart transplant, are less known. We studied retrospectively four patients who suffered cardiogenic shock during their hospital stay and became heart transplant candidates. Their PSA serum levels were very high suggesting the presence of PCa. Our findings have shown that elevated PSA serum levels in these patients were not related to PCa and they might be associated with cardiogenic shock. This clinical case study adds evidences to the fact that cardiogenic shock is an important cause of PSA FP results, therefore it cannot be used as a reliable marker of PCa in this clinical condition and positive results should be properly interpreted.

  • Genetic and phenotypic analysis of a rare asymptomatic case of a homozygous Chinese Gγ+(Aγδβ)0-thalassemia deletion in a Chinese family
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-22
    Li Du, Danqing Qin, Jicheng Wang, Lihua Yu, Cuize Yao, Ling Liu, Yanxia Zhang, Tingting Hu, Tenglong Yuan, Jie Liang, Aihua Yin
  • Multi-platform analytical evaluation of the Beckman Coulter Access high-sensitivity troponin I assay across different laboratory sites using Barricor plasma
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-16
    Joshua E. Raizman, Albert K.Y. Tsui, Bobbi-Lynn Goudreau, Anna K Füzéry, Mathew Estey, Hossein Sadrzadeh, Trefor Higgins

    Objectives Previous analytical evaluations of the Beckman Access high sensitivity troponin (hsTn) I assay have focused on single platforms and laboratories. The purpose of this study was to determine assay robustness across different platform models at multiple sites, platform-specific characteristics, and equivalence to other hsTn methods to be used in a large laboratory network. Methods Barricor plasma was used to assess imprecision, linearity, sensitivity (limit of blank and detection, LOB/LOD), and comparability to the conventional AccuTnI+3 and other hsTn assays. Studies were conducted in at least 3 laboratories using multiple DxI800 and Access2 platforms. Results Within-laboratory precision was <10% across all target patient pool concentrations, however, DxI800 mean values were 20% higher than Access2 in the range of 3.6 to 44.9 ng/L. LOBs and LODs were lower on the DxI800, 0.27 and 0.90 ng/L, respectively, compared to 2.9 and 3.2 ng/L on Access2. Both showed excellent linearity across the full range. In method comparison to AccuTnI+3, DxI800 showed a higher slope (0.9417 versus 0.8495) and positive bias (18.1% versus -9.9%) compared to Access2, a trend further increased at concentrations <150 ng/L. At values <150ng/L, there was good agreement with Abbott hsTnI (slope=1.017, r=0.932), but poor agreement with the Roche hsTnT assay (slope=1.687, r=0.589). Inter-laboratory split sample comparisons across 2 DxI800 and 9 Access2 sites showed equivalency between them, except at low concentrations <10ng/L where DxI800 was 2.8 ng/L higher (p<0.001). Conclusions The Beckman hsTnI assay showed robust analytical performance across different laboratories/platforms. Excellent precision and sensitivity make it suitable for accelerated AMI protocols. However, discrepancies in assay performance between platforms can lead to major errors when using rapid rule-out algorithm.

  • A novel approach to remove interference of therapeutic monoclonal antibody with serum protein electrophoresis
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-11
    Li Liu, Michael R. Shurin, Sarah E. Wheeler

    Objectives Multiple myeloma (MM) is characterized by malignant growth of plasma cells, usually producing a monoclonal antibody (mAb). New treatments for MM include therapeutic monoclonal antibodies (tmAbs), but patients treated with tmAb demonstrate interference on serum electrophoresis (SPE) and immunoprecipitation electrophoresis (IEP). Evaluation of treatment efficacy and determination of MM remission include SPE and IEP which identifies mAb, but cannot differentiate between disease associated mAb and tmAb. We hypothesized that tmAb could be removed from patient sera before testing by SPE and IEP to provide accurate diagnoses for clinicians. Design and methods We developed the Antigen Specific therapeutic monoclonal Antibody Depletion Assay (ASADA), that utilizes magnetic beads coated with the cognate antigen of the tmAbs, to deplete two different tmAb (daratumumab, elotuzumab) from saline and patient sera and assessed for complete removal of tmAb by SPE and IEP. Results We found that tmAb could be efficiently removed from saline and patient sera. ASADA demonstrated acceptable analytical specificity and sensitivity in IEP. Recovery of appropriate quantitative values by SPE was demonstrated with clinically acceptable precision. A single bead cocktail could be used to treat both daratumumab and elotuzumab. Conclusions This demonstrates proof of principle that ASADA can be used to remove current and future tmAb from patient sera, regardless of platform. This research provides for accurate diagnosis, disease monitoring, and remission status in MM patients being treated with tmAb.

  • Automated Analysis of Dried Urine Spot (DUS) Samples for Toxicology Screening
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-07
    Abed Pablo, Autumn R. Breaud, William Clarke

    Background Dried specimens have been proposed in multiple environments to minimize costs associated with specimen storage and shipping in clinical studies. This report describes the development and validation of an automated method for qualitative toxicology screening of dried urine samples using LC-MS/MS. Methods Urine standards containing 41 compounds were prepared and applied to filter paper cards. Dried urine was eluted from the cards using a Dried Blood Spot (DBS) autosampler from Spark Holland. , which was plumbed inline with a Thermo Scientific Turboflow chromatography system for subsequent MS/MS detection with selected reaction monitoring. Limits of detection, precision of peak areas, repeatability, and carryover studies were conducted. Concordance with a reference LC-MS/MS method using liquid samples was evaluated using remnant discarded specimens. Results The limit of detection ranged from 5-75 ng/mL for most compounds. At the LOD for each analyte, the peak area precision ranged from 8 to 29%. For 20 repeat injections of samples spiked at + or - 25% of the LOD, there was a 4% false positive rate for the 75% x LOD samples, and a 0.4% false negative rate for the +125% x LOD samples. In comparing 40 known positive specimens analyzed with the DUS method and a liquid urine reference method, there was 88% agreement. Analysis of 10 known negative specimens yielded negative results. There was no significant carryover detected up to 2,000 ng/mL for any of the analytes in the assay. Conclusion Using a robotic DUS sampling an inline HTLC-MS/MS system, we have developed and validated a fully-automated and robust method for multi-analyte detection of drugs of abuse in dried urine specimens.

  • Estimating short- and long-term reference change values and index of individuality for tests of platelet function
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-04
    Brooke M. Katzman, Amy M. Wockenfus, Renee J. Scott, Sandra C. Bryant, Allan S. Jaffe, Brad S. Karon

    Background In order to manage risks of bleeding and thrombosis after some surgical procedures, platelet function is often measured repeatedly over days or weeks using laboratory tests of platelet function. To interpret test results in the perioperative period, it is necessary to understand analytical, biological and between-person variation. Methods We collected three separate blood specimens from 16 healthy volunteers on the first study day, and one additional specimen from each volunteer 1, 2, and 3 months later. Arachidonic acid-induced and adenosine diphosphate (ADP)-induced platelet function were measured in duplicate by whole blood impedance aggregometry using Multiplate (ASPI/ADP tests) and VerifyNow (Aspirin Reaction Units [ARU] and P2Y12 Reaction Units [PRU]). The analytical variation (CVA), within-subject variation (CVI), between-subject variation (CVG), index of individuality (II), and reference change values (RCV) were calculated. Results VerifyNow ARU demonstrated the smallest short-term and long-term variability (CVA, CVI, and CVG ~1%), resulting in short- and long-term RCV values <5%. II was also higher (1.92) for VerifyNow ARU than other platelet function tests. Multiplate ASPI and ADP tests had the highest RCV both short-(19.0% and 25.2%, respectively) and long-term (32.1% and 39.6%, respectively) due to increased CVA (>5%) and CVI (3.9–13.1%). VerifyNow PRU had a lower RCV than Multiplate ADP; but was the only test with II <0.6. Conclusions VerifyNow ARU results can be interpreted relative to a fixed cut-off or population-based reference interval; or relative to small changes in an individual’s previous values. VerifyNow PRU and Multiplate ASPI and ADP tests should only be interpreted based upon relative change; and can only distinguish relatively large (>23%) changes over several weeks.

  • Comparison of early cardiovascular risk among Brazilian and African university students
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-01
    Ederson Laurindo Holanda de Sousa, Jânio Emanuel Andrade Cavalcante, Daniel Freire de Sousa, Jamile Magalhães Ferreira, Richard Rarison Cavalcante Meneses, Duaran Lopes Sousa, Allysson Jordan Xavier Silva, Raimundo Rigoberto Barbosa Xavier Filho, Elias da Silva dos Santos, Alexandre Havt, Nagila Raquel Teixeira Damasceno, Tiago Lima Sampaio, Maria Goretti Rodrigues Queiroz
  • Characterization of biotin interference in 21 Vitros 5600 immunoassays and risk mitigation for patient safety at a large academic medical center
    Clin. Biochem. (IF 2.43) Pub Date : 2019-10-31
    Heather M. Stieglitz, Nichole Korpi-Steiner

    Background Biotin and streptavidin are commonly used reagents in clinical immunoassays. Several cases of biotin interference with immunoassay testing for patients taking biotin supplements have been reported, yet, not all analytes and platforms susceptible to biotin interference have been characterized. The objectives of this study are to characterize biotin interference with 21 immunoassays using the Ortho Clinical Diagnostics Vitros 5600, evaluate a biotin-depletion method, and apply risk mitigation strategies for biotin interference during routine clinical testing at our institution. Methods Residual serum without and with increasing concentrations of exogenous biotin were used to evaluate biotin interference with 21 immunoassays using the Vitros 5600. Biotin-depletion was evaluated by comparing measured analyte concentrations in serum with and without exogenous biotin and streptavidin-microparticle pretreatment. Focused education for healthcare professionals about biotin interference was performed in February 2018. Samples with suspected biotin interference were investigated using this biotin-depletion method, and analyte testing by alternate methodology for select samples. Results Exogenous biotin in serum caused dose-dependent negative biases in 15 immunometric assays, and dose-dependent positive biases in 6 competitive immunoassays. Streptavidin-microparticle pretreatment of serum containing exogenous biotin demonstrated recoveries 100 +/- 15% of expected values for all 21 analytes. Physicians identified 21 samples suspicious for biotin interference over 11 months, and streptavidin-microparticle pretreatment verified 11 cases of biotin interference. Conclusions Analytical bias caused by biotin interference is dependent on biotin concentration but independent of analyte concentration for immunometric methods using the Vitros 5600, and dependent on both biotin and analyte concentration for competitive immunoassays. Multi-disciplinary education and a lab streptavidin-microparticle pretreatment method help mitigate risk of erroneous results due to biotin interference for patient safety.

  • Alzheimer's disease: Making the point.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-05-28
    Sergio Bernardini,Tomas Zima

  • Differential diagnosis between Alzheimer's disease and other dementias: Role of cerebrospinal fluid biomarkers.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-19
    Lucia Farotti,Federica Nicoletta Sepe,Andrea Toja,Roberta Rinaldi,Lucilla Parnetti

  • Evolving Hyperthyroidism?
    Clin. Biochem. (IF 2.43) Pub Date : 2019-11-26
    Qing H Meng

  • Playing the game of scientific publishing.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-08-05
    Clare Fiala,Eleftherios P Diamandis

  • High-sensitivity cardiac troponin testing during and after ACS: Complexed or not?
    Clin. Biochem. (IF 2.43) Pub Date : 2019-07-31
    Peter Hwang,Alma Mingels,Peter A Kavsak

  • Clinical significance of inflammatory and fibrogenic cytokines in diabetic nephropathy.
    Clin. Biochem. (IF 2.43) Pub Date : 2012-03-17
    Hala O El Mesallamy,Hanaa H Ahmed,Atef A Bassyouni,Amira S Ahmed

    OBJECTIVES To study the role of inflammatory chemokine; monocyte chemoattractant protein-1 (MCP-1), and fibrogenic markers [transforming growth factor beta-1 (TGF-β(1)), connective tissue growth factor (CTGF) and fibronectin (FN)] in diabetic nephropathy (DN). DESIGN AND METHODS This study included 17 control and 65 type 2 diabetic subjects (18 normoalbuminuric, 22 microalbuminuric and 25 macroalbuminuric). Demographic characteristics, diabetic index and kidney function tests were monitored. Serum TGF-β(1), plasma CTGF, MCP-1 and FN levels were assayed. RESULTS Microalbuminuric and macroalbuminuric subjects showed a significant elevation in TGF-β(1), CTGF, MCP-1 and FN levels as compared with control and normoalbuminuric subjects. There was positive correlation between these markers and fasting plasma glucose, albumin excretion rate and with each other. CONCLUSION This study revealed the importance of these markers in DN pathogenesis which is powered by their association and thus the possibility of their use as biochemical markers in DN was suggested.

  • Assessment of thyroid function in intensive care unit patients by liquid chromatography tandem mass spectrometry methods.
    Clin. Biochem. (IF 2.43) Pub Date : 2016-11-29
    Kerry J Welsh,Brian R Stolze,Xiaolin Yu,Trisha R Podsiadlo,Lisa S Kim,Steven J Soldin

    OBJECTIVES Patients with non-thyroidal illness syndrome have many abnormalities in thyroid hormone tests. Such patients have medical comorbidities associated with low serum proteins and are on multiple medications that interfere with thyroid hormone measurement by immunoassay platforms. It is unknown if these thyroid hormone measurements reflect physiologic conditions or if they are artifacts of testing methodology. METHODS Fifty patients were selected from the intensive care unit (ICU) from our institution. Total and free thyroid hormones in plasma were measured by gold standard liquid chromatography-tandem mass spectrometry (LC-MSMS). The results were compared to the Roche Cobas 6000. Patient medical comorbidities and binding protein levels were assessed. RESULTS Concentrations of total 3,5,5'-triidothyronine (TT3) and total thyroxine (TT4) were significantly more likely to be low by LC-MSMS compared to immunoassay. Free 3,5,5'-triidothyronine (FT3) levels were similar by immunoassay and LC-MSMS. However, FT4 concentrations were mildly elevated for many patients when measured by ultrafiltration LC-MSMS (19/50, 38%) compared to 1/50 (2%) when measured by immunoassay (p=0.0001). Decreased albumin and thyroxine binding globulin were common and patients were on an average of 11.7±5.0 medications, all factors known to interfere with results found on immunoassays. CONCLUSIONS Marked discrepancies in thyroid hormone measurement were noted between reference LC-MSMS and a common immunoassay platform. It is hypothesized that T4 binding to low affinity albumin is displaced by several drugs, raising concentrations of FT4 by LC-MSMS compared to immunoassay, and that the immunoassay values are falsely decreased due to low binding proteins in our patient population.

  • Is measurement of TT3 by immunoassay reliable at low concentrations? A comparison of the Roche Cobas 6000 vs. LC-MSMS.
    Clin. Biochem. (IF 2.43) Pub Date : 2016-02-18
    Likhona Siphe Masika,Zhen Zhao,Steven John Soldin

    OBJECTIVES Thyroid dysfunction is a common medical condition affecting an estimated 30 million people in the US alone. Employing gold standard Liquid chromatography-tandem mass spectrometry (LC-MSMS) methods we have examined the extent of inaccuracy of immunoassay (IA) measurement for total T3 (TT3) at low, normal and high concentrations. DESIGN AND METHODS 268 TT3 Roche Cobas 6000 immunoassay TT3 values (covering the low, normal, and high ranges) were compared with LC-MSMS results. RESULTS At TT3 concentrations between 50 and 113ng/dL (conversion factor for TT3 to SI Units is ng/dL×0.0154=nmol/L), n=122, LC-MSMS values were lower than immunoassay with 72% found to be below the 2.5th percentile by LC-MSMS compared to 27% for immunoassay. Strikingly 45% of the patients classified as normal TT3 by immunoassay were defined as lower than the 2.5th percentile by LC-MSMS. Only 38 of the 122 patients with low T3's were not receiving T4. In this latter group all of whom had TSH's>3.7mIU/L, 74% of results by LC-MSMS were below the 2.5th percentile while only 21% were below the 2.5th percentile by IA. The clinical consequences of these inaccuracies may affect whether dosing with T4 or combination of T4 with T3 is selected for treatment. Finally the correlation of TT3 with TSH was far superior when TT3 was measured by LC-MSMS. A typical case which demonstrates our message is included. CONCLUSION T3 being the active hormone needs to be reliably measured and if the patient has low TT3 and hypothyroid symptoms persist; treatment with T3 should be considered. A typical case report is included to illustrate the problems of inaccurate immunoassay results for TT3. Measurement of TT3 by immunoassay at low concentrations is less than optimal and often provides the clinician with a normal result when the LC-MSMS method and the patient's clinical condition suggests that supplementation with T3 (as in combination therapy) may be required to optimize patient care.

  • Mass spectrometric quantification of salivary metanephrines-A study in healthy subjects.
    Clin. Biochem. (IF 2.43) Pub Date : 2016-02-14
    Thamara E Osinga,Anouk N A van der Horst-Schrivers,Martijn van Faassen,Michiel N Kerstens,Robin P F Dullaart,Karel Pacak,Thera P Links,Ido P Kema

    BACKGROUND Determination of metanephrine (MN), normetanephrine (NMN), and 3-methoxytyramine (3-MT) in saliva may offer potential diagnostic advantages in diagnosing pheochromocytoma. METHODS In this preliminary study, we determined metanephrine concentrations in saliva of healthy subjects and the relationship with simultaneously measured plasma metanephrines. We also studied the possible influence of pre-analytical conditions such as a collection device, awakening, posture, and eating on the salivary metanephrine levels. RESULTS Eleven healthy subjects were included. Fasting blood and saliva samples were collected in seated position and after 30min of horizontal rest. Plasma and salivary MN, NMN, and 3-MT concentrations were determined using a high-performance liquid chromatography tandem mass spectrometric technique (LC-MS/MS) with automated solid phase extraction sample preparation. Metanephrines were detectable in saliva from all participants both in seated and supine position. No significant correlations were observed between the MN, NMN, and 3-MT concentrations in saliva and plasma in seated or supine position. Furthermore, there was no difference between MN, NMN, and 3-MT samples collected with or without a collection device. CONCLUSION Metanephrines can be detected in saliva with LC-MS/MS with sufficient sensitivity and precision. Our findings warrant evaluation of salivary metanephrine measurement as a novel laboratory tool in the work-up of patients suspected of having a pheochromocytoma.

  • Intermuscular adipose tissue is associated with monocyte chemoattractant protein-1, independent of visceral adipose tissue.
    Clin. Biochem. (IF 2.43) Pub Date : 2015-12-27
    Ji-Hee Haam,Young-Sang Kim,Hyung Suk Koo,Juhee Haam,Nam Kyoung Seo,Hyung Yuk Kim,Kyung-Chae Park,Kye-Seon Park,Moon Jong Kim

    OBJECTIVES Emerging evidence suggests that intermuscular adipose tissue is a risk factor for insulin resistance, but the underlying mechanism still remains unclear. We investigated whether the levels of leptin, adiponectin, and monocyte chemoattractant protein-1 are associated with intermuscular adipose tissue in obese subjects. DESIGN AND METHODS A cross-sectional study was performed on 77 obese Korean women. Areas of visceral adipose tissue, subcutaneous adipose tissue, and intermuscular adipose tissue were measured by computed tomography scan, and serum concentrations of adipokines were measured by enzyme-linked immunosorbent assays. Correlation between the levels of adipokines and the fat areas was assessed using Pearson correlation and covariate-adjusted multivariable regression. RESULTS Leptin was positively correlated with subcutaneous adipose tissue (r=0.452, P<0.001), fasting insulin (r=0.403, P<0.001), and homeostasis model assessment of insulin resistance (r=0.360, P=0.001), whereas monocyte chemoattractant protein-1 was positively correlated with intermuscular adipose tissue (r=0.483, P<0.001). After adjustment for age, height, and other body composition metrics, leptin was still related to subcutaneous adipose tissue (β=0.390, P=0.001). Monocyte chemoattractant protein-1 was associated with intermuscular adipose tissue (β=0.433, P=0.001) after adjustment for visceral adipose tissue. CONCLUSIONS Intermuscular adipose tissue was correlated with monocyte chemoattractant protein-1, suggesting its role in the development of insulin resistance.

  • Oxidative stress is associated with weight gain in recipients at 12-months following kidney transplantation.
    Clin. Biochem. (IF 2.43) Pub Date : 2015-11-08
    Young-Eun Cho,Hyung-Suk Kim,Chen Lai,Ansley Stanfill,Ann Cashion

    OBJECTIVE Weight gain after kidney transplantation (Tx) is considered a risk factor for poor outcomes. Increased oxidative stress is associated with not only chronic renal disease and Tx, but also obesity and cardiovascular disease. The aim of this pilot study was to test whether oxidative stress is related to weight gain at 12-months after kidney Tx and to obtain preliminary insight into potential mechanisms involved. DESIGN & METHODS Recipients (n=33) were classified into two groups; weight loss and weight gain, based on their weight changes at 12-months post-transplant. Total antioxidant capacity (TAOC) and lipid peroxidation (TBARS) were measured to evaluate oxidative stress from plasma at baseline and 12-months. A secondary data analysis was conducted to identify potential gene regulation. RESULTS Seventeen recipients lost (-6.63±5.52kg), and sixteen recipients gained weight (8.94±6.18kg). TAOC was significantly decreased at 12-months compared to baseline for the total group, however, there was no significant difference between groups at either time point. TBARS was higher in weight gain group, at both time points, and it was significantly higher at 12-months (p=0.012). Gene expression profiling analysis showed that 7 transcripts annotated to reactive oxygen species related genes in adipose tissue were expressed significantly lower in weight gain group at baseline, which might be a negative feedback mechanism to reduce oxidative stress. CONCLUSION These results may indicate that elevated oxidative stress (TBARS) is associated with weight gain after kidney Tx and that incorporating early clinical prevention strategies known to decrease oxidative stress could be recommended.

  • CUSUM-Logistic Regression analysis for the rapid detection of errors in clinical laboratory test results.
    Clin. Biochem. (IF 2.43) Pub Date : 2015-11-03
    Maureen L Sampson,Verena Gounden,Hendrik E van Deventer,Alan T Remaley

    OBJECTIVE The main drawback of the periodic analysis of quality control (QC) material is that test performance is not monitored in time periods between QC analyses, potentially leading to the reporting of faulty test results. The objective of this study was to develop a patient based QC procedure for the more timely detection of test errors. METHOD Results from a Chem-14 panel measured on the Beckman LX20 analyzer were used to develop the model. Each test result was predicted from the other 13 members of the panel by multiple regression, which resulted in correlation coefficients between the predicted and measured result of >0.7 for 8 of the 14 tests. A logistic regression model, which utilized the measured test result, the predicted test result, the day of the week and time of day, was then developed for predicting test errors. The output of the logistic regression was tallied by a daily CUSUM approach and used to predict test errors, with a fixed specificity of 90%. RESULTS The mean average run length (ARL) before error detection by CUSUM-Logistic Regression (CSLR) was 20 with a mean sensitivity of 97%, which was considerably shorter than the mean ARL of 53 (sensitivity 87.5%) for a simple prediction model that only used the measured result for error detection. CONCLUSION A CUSUM-Logistic Regression analysis of patient laboratory data can be an effective approach for the rapid and sensitive detection of clinical laboratory errors.

  • High sensitivity C-reactive protein (Hs-CRP) remains highly stable in long-term archived human serum.
    Clin. Biochem. (IF 2.43) Pub Date : 2014-01-01
    Ayo P Doumatey,Jie Zhou,Adebowale Adeyemo,Charles Rotimi

    BACKGROUND The stability of biomarkers in stored biomedical samples is crucial, especially when storage is for extended periods of time. High-sensitivity CRP (Hs-CRP) is a biomarker of low grade inflammation that is extensively used to identify and study cardiovascular and/or inflammatory processes in clinical care and large epidemiologic studies. Therefore, assessing Hs-CRP stability in archived samples at a given temperature is important to ensure precision of measurements over time and the validity of studies using archived samples. METHODS We evaluated the stability of Hs-CRP in 30 randomly selected human serum samples by measuring Hs-CRP concentrations in freshly collected sample [Hs-CRP (0)] and in the same set of samples after 7-11years of storage at -80°C [Hs-CRP (LT)]. RESULTS Hs-CRP did not significantly change up to 11years of storage at -80°C as shown by a negligible median difference between Hs-CRP (0) and Hs-CRP (LT), delta(Hs-CRP (0)-Hs-CRP (LT))=-0.01, p=0.45. There was a good concordance and agreement between Hs-CRP (0) and Hs-CRP (LT) as measured respectively by Lin's coefficient of correlation (ρC=0.98) and Bland-Altman analysis (mean difference=-0.02, 95% CI [-0.04-0.0045] p=0.107). In addition, the data also suggest that the time elapsed between collection and Hs-CRP measurement does not affect Hs-CRP stability over time when samples are kept under the appropriate conditions. CONCLUSIONS Long-term storage at -80°C for up to 11years did not significantly affect the stability of serum Hs-CRP. Given the cost and time for collecting fresh samples, this observation represents an important finding for biomedical research and clinical care.

  • Digital pathology and image analysis augment biospecimen annotation and biobank quality assurance harmonization.
    Clin. Biochem. (IF 2.43) Pub Date : 2013-12-24
    Bih-Rong Wei,R Mark Simpson

    Standardization of biorepository best practices will enhance the quality of translational biomedical research utilizing patient-derived biobank specimens. Harmonization of pathology quality assurance procedures for biobank accessions has lagged behind other avenues of biospecimen research and biobank development. Comprehension of the cellular content of biorepository specimens is important for discovery of tissue-specific clinically relevant biomarkers for diagnosis and treatment. While rapidly emerging technologies in molecular analyses and data mining create focus on appropriate measures for minimizing pre-analytic artifact-inducing variables, less attention gets paid to annotating the constituent makeup of biospecimens for more effective specimen selection by biobank clients. Both pre-analytic tissue processing and specimen composition influence acquisition of relevant macromolecules for downstream assays. Pathologist review of biorepository submissions, particularly tissues as part of quality assurance procedures, helps to ensure that the intended target cells are present and in sufficient quantity in accessioned specimens. This manual procedure can be tedious and subjective. Incorporating digital pathology into biobank quality assurance procedures, using automated pattern recognition morphometric image analysis to quantify tissue feature areas in digital whole slide images of tissue sections, can minimize variability and subjectivity associated with routine pathologic evaluations in biorepositories. Whole-slide images and pathologist-reviewed morphometric analyses can be provided to researchers to guide specimen selection. Harmonization of pathology quality assurance methods that minimize subjectivity and improve reproducibility among collections would facilitate research-relevant specimen selection by investigators and could facilitate information sharing in an integrated network approach to biobanking.

  • Blood collection tube-related alterations in analyte concentrations in quality control material and serum specimens.
    Clin. Biochem. (IF 2.43) Pub Date : 2013-11-19
    Raffick A R Bowen,Annie Sattayapiwat,Verena Gounden,Alan T Remaley

    OBJECTIVES Several previous studies have described the effects of interfering substances on clinical assay results; however, the effects of exogenous substances, particularly additives from blood collection tubes on quality control (QC) specimens and serum specimens have not been well examined. This study examines the effects of blood-collection tube additives on total triiodothyronine (TT3), and thyroxine (TT4), cortisol, and routine clinical chemistry tests in QC and serum specimens from apparently healthy volunteers. METHODS QC and serum specimens were poured or collected into different blood collection tubes. TT3 and TT4, cortisol, and routine chemistry tests were analyzed from the different blood-collection tube types. RESULTS The findings of this study demonstrate statistically and/or clinically significant blood collection tube-related alterations in the TT3, TT4, and cortisol concentrations of QC specimens and TT4 concentrations from serum specimens. CONCLUSIONS These findings have important implications for clinical laboratories, demonstrating that QC specimens should ideally, like patients' specimens, be poured into blood collection tubes. This strategy would reveal any adverse effects caused by blood collection tubes, which otherwise would not likely be detected by most routine QC practices. The results of this study also show the importance of producing blood collection tubes that contain additives that are truly inert and do not adversely affect clinical laboratory testing.

  • Performance evaluation of Siemens ADVIA Centaur and Roche MODULAR Analytics E170 Total 25-OH Vitamin D assays.
    Clin. Biochem. (IF 2.43) Pub Date : 2012-06-19
    Yu Chen,Lois Kinney,Andrea Božović,Hilary Smith,Heather Tarr,Eleftherios P Diamandis,Adrien LeBlanc

    OBJECTIVES To evaluate the newly developed Roche MODULAR Analytics E170 Total Vitamin D and the Siemens ADVIA Centaur Vitamin D Total assays. MATERIALS AND METHODS Assays were evaluated using the Clinical and Laboratory Standards Institute protocols. Split patient samples were compared with LC-MS/MS and DiaSorin LIAISON assays (n=79 including 15 specimens with detectable endogenous 25-OH vitamin D(2)). Assay accuracy was also evaluated using the Vitamin D External Quality Assessment Scheme (DEQAS) samples. RESULTS The ADVIA Centaur and E170 assays demonstrated maximum total CVs of 14.1% and 5.9%, respectively. Both showed excellent linearity (R(2)>0.99). The ADVIA Centaur assay demonstrated interference with bilirubin at 800 μmol/L, hemolysis at 1.25 g/L, and triglycerides at 2.8 mmol/L. Compared to LC-MS/MS, the ADVIA Centaur assay demonstrated a R(2) value of 0.893, average bias of -8.8%; the E170 assay an R(2) value of 0.872, average bias of 14.3% with underestimation of 25-OH vitamin D(2). Compared to the LIAISON assay, the ADVIA Centaur assay demonstrated an R(2) value of 0.781, average bias of -17.3%; the E170 assay an R(2) value of 0.823, average bias of 11.4%. The ADVIA Centaur and E170 assays demonstrated a biases of <20% in 10/10 and 8/10 DEQAS samples, respectively. CONCLUSIONS The ADVIA Centaur and E170 vitamin D assays demonstrated acceptable linearity, imprecision, and accuracy. The E170 assay demonstrated consistent underestimation of 25-OH vitamin D(2) levels. Compared with LC-MS/MS, the ADVIA Centaur assay demonstrated a higher R(2) value and a smaller average bias than the E170 assay.

  • Elevated vitamin B₁₂ levels in autoimmune lymphoproliferative syndrome attributable to elevated haptocorrin in lymphocytes.
    Clin. Biochem. (IF 2.43) Pub Date : 2012-02-07
    Raffick A R Bowen,Kennichi C Dowdell,Janet K Dale,Steven K Drake,Thomas A Fleisher,Glen L Hortin,Alan T Remaley,Ebba Nexo,V Koneti Rao

    OBJECTIVE Identify the etiology of elevated B(12) in autoimmune lymphoproliferative syndrome (ALPS). DESIGN Peripheral blood of ALPS patients with elevated B(12) and controls were evaluated. RESULTS Total and holo-haptocorrin (HC) levels were 26- and 23-fold higher in ALPS patients, respectively. No abnormal B(12)-binding proteins were found. Western blot revealed HC in lymphocyte lysates only from ALPS patients. CONCLUSION Elevated concentrations of B(12) found in ALPS patients were due to increased lymphocyte expression of HC.

  • Development and validation of a comprehensive mutation and deletion detection assay for SDHB, SDHC, and SDHD.
    Clin. Biochem. (IF 2.43) Pub Date : 2010-02-16
    Dragana Milosevic,Patrick Lundquist,Kendall Cradic,Noemi Vidal-Folch,ThanhTruc Huynh,Karel Pacak,Stefan K G Grebe

    BACKGROUND Lack of sequencing validation and complexity of deletion testing hinder genetic diagnosis of SDH-associated paraganglioma/pheochromocytoma. METHODS We developed sequencing assays and multiplex ligation-dependent probe amplification (MLPA) deletion detection for SDHB, SDHC and SDHD. Clinical performance was validated on 141 blinded samples, previously tested at NIH. RESULTS Sequencing and deletion detection were highly reproducible and agreed with previous NIH results in 99.3% and 100%, respectively. CONCLUSIONS DNA sequencing combined with MLPA allows reliable and simplified genotyping of SDHB, SDHC and SDHD.

  • Identification of myocardial injury in the emergency setting.
    Clin. Biochem. (IF 2.43) Pub Date : 2009-12-23
    Peter A Kavsak,Andrew Worster,John J You,Mark Oremus,Adell Elsharif,Stephen A Hill,P J Devereaux,Andrew R MacRae,Allan S Jaffe

    Within the past decade, the use of biomarkers to detect myocardial injury in the emergency department (ED) has been given increasing prominence as evident by the numerous studies and guidelines documenting their use. This review details the scope of the clinical problem, the history of changes in the definition of myocardial infarction (MI) and the new approaches, as well as suggestions for using laboratory biomarkers in the early detection of MI in the ED.

  • The use of a cytokine panel to define the long-term risk stratification of heart failure/death in patients presenting with chest pain to the emergency department.
    Clin. Biochem. (IF 2.43) Pub Date : 2009-11-17
    Peter A Kavsak,Alice M Newman,Dennis T Ko,Andrew R Macrae,Allan S Jaffe

    OBJECTIVE To determine if a cytokine panel could be informative regarding subsequent heart failure(HF)/death. DESIGN AND METHODS In 216 subjects presenting with chest pain to an emergency department in 1996, EDTA plasma (-70 degrees C) was thawed for IL-6, MCP-1, IL-10, VEGF, EGF measurement. RESULTS Subjects with any three cytokines elevated were at higher risk for HF/death compared to those with < or = two cytokines elevated. DISCUSSION A cytokine panel might be useful for risk stratification for HF/death.

  • AD biomarker discovery in CSF and in alternative matrices.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-08-23
    Giulia Sancesario,Sergio Bernardini

    Core Alzheimer's Disease (AD) biomarkers are the cerebrospinal fluid (CSF) proteins amyloid β42 and β40, and the tau proteins, total and phosphorylated. Their use is recommended by research guidelines for diagnostic purpose and for stratification of patients for clinical trials. However, novel potential biomarkers are needed, which can mirror risk factors and other different mechanisms of the disease, hopefully in less invasive biological fluids or matrices. Studies on blood, urine, saliva, tears gave promising results, and several novel molecules have been identified, as potential brain derived biomarkers, thanks to the development of novel ultrasensitive technologies. In this review, we discuss about advantages and limits of the classical CSF biomarkers of AD, as well as of novel CSF candidate biomarkers and recent promises from alternative matrices.

  • Assessment of lipid peroxidation and artificial neural network models in early Alzheimer Disease diagnosis.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-07-19
    Carmen Peña-Bautista,Thierry Durand,Camille Oger,Miguel Baquero,Máximo Vento,Consuelo Cháfer-Pericás

    OBJECTIVE Lipid peroxidation constitutes a molecular mechanism involved in early Alzheimer Disease (AD) stages, and artificial neural network (ANN) analysis is a promising non-linear regression model, characterized by its high flexibility and utility in clinical diagnosis. ANN simulates neuron learning procedures and it could provide good diagnostic performances in this complex and heterogeneous disease compared with linear regression analysis. DESIGN AND METHODS In our study, a new set of lipid peroxidation compounds were determined in urine and plasma samples from patients diagnosed with early Alzheimer Disease (n = 70) and healthy controls (n = 26) by means of ultra-performance liquid chromatography coupled with tandem mass-spectrometry. Then, a model based on ANN was developed to classify groups of participants. RESULTS The diagnostic performances obtained using an ANN model for each biological matrix were compared with the corresponding linear regression model based on partial least squares (PLS), and with the non-linear (radial and polynomial) support vector machine (SVM) models. Better accuracy, in terms of receiver operating characteristic-area under curve (ROC-AUC), was obtained for the ANN models (ROC-AUC 0.882 in plasma and 0.839 in urine) than for PLS and SVM models. CONCLUSION Lipid peroxidation and ANN constitute a useful approach to establish a reliable diagnosis when the prognosis is complex, multidimensional and non-linear.

  • The standardization of cerebrospinal fluid markers and neuropathological diagnoses brings to light the frequent complexity of concomitant pathology in Alzheimer's disease: The next challenge for biochemical markers?
    Clin. Biochem. (IF 2.43) Pub Date : 2019-06-14
    Tanguy Fenouil,Anthony Fourier,Isabelle Quadrio,Nathalie Streichenberger,Sergio Bernardini,Tomáš Zima,Armand Perret-Liaudet,David Meyronet

    During the last two decades, neuropathological examination of the brain has evolved both technically and scientifically. The increasing use of immunohistochemistry to detect protein aggregates paralleled a better understanding of neuroanatomical progression of protein deposition. As a consequence, an international effort was achieved to standardize hyperphosphorylated-Tau (phospho-TAU), ßAmyloid (Aß), alpha syncuclein (alpha-syn), phosphorylated transactive response DNA-binding protein 43 (phospho-TDP43) and vascular pathology detection. Meanwhile harmonized staging systems emerged in order to increase inter rater reproducibility. Therefore, a refined definition of Alzheimer's disease was recommended., a clearer picture of the neuropathological lesions diversity emerged secondarily to the systematic assessment of concomitant pathology highlighting finally a low rate of pure AD pathology. This brings new challenges to laboratory medicine in the field of cerebrospinal fluid (CSF) markers of Alzheimer's disease: how to further validate total Tau, phospho-TAU, Aß40 and Aß42 and new marker level cut-offs while autopsy rates are declining?

  • Elecsys® Total-Tau and Phospho-Tau (181P) CSF assays: Analytical performance of the novel, fully automated immunoassays for quantification of tau proteins in human cerebrospinal fluid.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-05-28
    Valeria Lifke,Gwendlyn Kollmorgen,Ekaterina Manuilova,Tobias Oelschlaegel,Lars Hillringhaus,Monika Widmann,Christine A F von Arnim,Markus Otto,Robert H Christenson,Jennifer L Powers,Leslie M Shaw,Oskar Hansson,James D Doecke,Qiao-Xin Li,Charlotte Teunissen,Hayrettin Tumani,Kaj Blennow

    BACKGROUND Total tau (tTau) and phosphorylated 181P tau (pTau) are supportive diagnostic cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease. Manual CSF tau assays are limited by lot-to-lot and between-laboratory variability and long incubation/turnaround times. Elecsys® Total-Tau CSF and Phospho-Tau (181P) CSF immunoassays were developed for fully automated cobas e analyzers, allowing broader access in clinical practice and trials. METHODS Analytical performance, reproducibility, method comparisons with commercially available assays, and lot-to-lot and platform comparability (cobas e 601/411) of the Elecsys® CSF assays were assessed. Tau distributions and concentration ranges were evaluated in CSF samples from two clinical cohorts. RESULTS Both assays showed high sensitivity (limit of quantitation [LoQ]: 63 pg/mL [tTau]; 4 pg/mL [pTau]) and linearity over the measuring range (80-1300 pg/mL; 8-120 pg/mL), which covered the entire concentration range measured in clinical samples. Lot-to-lot and platform comparability demonstrated good consistency (Pearson's r: 0.998; 1.000). Multicenter evaluation coefficients of variation (CVs): repeatability, < 1.8%; intermediate precision, < 2.8%; between-laboratory variability, < 2.7% (both assays); and total reproducibility, < 6.7% (tTau) and < 4.7% (pTau). Elecsys® CSF assays demonstrated good correlation with commercially available tau assays. CONCLUSIONS Elecsys® Total-Tau CSF and Phospho-Tau (181P) CSF assays demonstrate good analytical performance with clinically relevant measuring ranges; data support their use in clinical trials and practice.

  • Method comparison study of the Elecsys® β-Amyloid (1-42) CSF assay versus comparator assays and LC-MS/MS.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-05-28
    Leslie M Shaw,Oskar Hansson,Ekaterina Manuilova,Colin L Masters,James D Doecke,Qiao-Xin Li,Sandra Rutz,Monika Widmann,Andreas Leinenbach,Kaj Blennow

    BACKGROUND Alzheimer's disease (AD) biomarkers, such as cerebrospinal fluid (CSF) amyloid-β (1-42; Aβ42), can provide high diagnostic accuracy. Several immunoassays are available for Aβ42 quantitation, but standardisation across assays remains an issue. We compared the Elecsys® β-Amyloid (1-42) CSF assay with three assays and two liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. METHODS Three method comparison studies evaluated the correlation between the Elecsys® β-Amyloid (1-42) CSF assay versus: INNOTEST® β-AMYLOID(1-42) (860 samples) and the Roche Diagnostics-developed LC-MS/MS method (250 samples); INNO-BIA AlzBio3 and the University of Pennsylvania (UPenn)-developed LC-MS/MS method (250 samples); and ADx-EUROIMMUN Beta-Amyloid (1-42) enzyme-linked immunosorbent assay (ELISA) (49 samples). RESULTS High correlation was demonstrated between Elecsys® β-Amyloid (1-42) CSF and comparator assays: INNOTEST® β-AMYLOID(1-42) (Spearman's ρ, 0.954); INNO-BIA AlzBio3 (Spearman's ρ, 0.864); ADx-EUROIMMUN Beta-Amyloid (1-42) ELISA (Pearson's r, 0.925). Elecsys® assay and LC-MS/MS measurements were highly correlated: Pearson's r, 0.949 (Roche Diagnostics-developed method) and 0.943 (UPenn-developed method). CONCLUSION Findings from this multicentre evaluation further support use of the Elecsys® β-Amyloid (1-42) CSF assay to aid AD diagnosis. CSF-based certified reference materials should improve agreement across assays and mass spectrometry-based methods, which is essential to establish a global uniform CSF Aβ42 cut-off to detect amyloid pathology.

  • Clinical aspects of Alzheimer's disease.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-30
    Martina Zvěřová

    Alzheimer's disease is a progressive, irreversible, incurable, neurodegenerative illness and the most common of the dementing disorders. It starts usually after 60 years of age and may span 8 to 12 years. The continuous and slow decline caused by this disease, is characterized by cognitive deterioration, loss of functional independence, changes in behaviour, and expanding needs for care. In the last three decades, the proteins predominating neuritic plaques and neurofibrillary tangles have been detected and researched: amyloid-beta protein in the plaques and hyperphosphorylated tau in the tangles. Alzheimer's disease is now considered a long-term process with a slow progress and with a prolonged development of pathological changes that precedes symptoms by years. AD is becoming one of the most problematic and expensive illness for the civilization, also known as "silent threat".

  • New molecular approaches to Alzheimer's disease.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-25
    Chiara Di Resta,Maurizio Ferrari

    Alzheimer's disease is a neurodegenerative disorder and the most common and devastating form of dementia. It affects mainly older people, accounting for 50-80% of dementia cases. The age is the main associated risk factor and based on the onset age, early-onset (EOAD) or late-onset (LOAD) forms are distinguished. AD has a strong impact both on the life-style of patients and their families and on the society, due to the high costs related to social and medical care. So far, despite the great advances in understanding of the AD pathogenesis, there is no a cure for this form of dementia and current available treatments are limited to temporarily relieve symptoms. In this review, firstly we give an overview of the current knowledge of the genetic basis of both forms of AD with a particular emphasis on the insights in the understanding of the pathogenic mechanisms of this disorder. Then we discuss the promising relevance of "omics sciences" and the open challenges of the application of Big Data in promoting precision medicine for AD.

  • Blood-based molecular signature of Alzheimer's disease via spectroscopy and metabolomics.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-08
    Lucie Habartová,Kateřina Hrubešová,Kamila Syslová,Jana Vondroušová,Zdeněk Fišar,Roman Jirák,Jiří Raboch,Vladimír Setnička

    OBJECTIVES With over 35 million cases worldwide, Alzheimer's disease (AD) represents the main cause of dementia. The differentiation of AD from other types of dementia is challenging and its early diagnosis is complicated. The established biomarkers are not only based on the invasive collection of cerebrospinal fluid, but also lack sufficient sensitivity and specificity. Therefore, much current effort is aimed at the identification of new biomarkers of AD in peripheral blood. DESIGN AND METHODS We focused on blood-based analyses using chiroptical spectroscopy (Raman optical activity, electronic circular dichroism) supplemented with conventional vibrational spectroscopy (infrared, Raman) and metabolomics (high-performance liquid chromatography with a high-resolution mass detection). RESULTS This unique approach enabled us to identify the spectral pattern of AD and variations in metabolite levels. Subsequent linear discriminant analysis of the spectral data resulted in differentiation between the AD patients and control subjects. CONCLUSIONS It may be stated that this less invasive approach has strong potential for the identification of disease-related changes within essential plasmatic biomolecules and metabolites.

  • Neuro-inflammation and anti-inflammatory treatment options for Alzheimer's disease.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-08
    Tomris Ozben,Serkan Ozben

    Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and dementia. The pathological characteristics of AD include the deposition of amyloid beta (Aβ), neurofibrillary tangles, and neuronal loss. There is evidence showing the involvement of inflammation in AD, including activated microglia within and surrounding senile plaques. Epidemiological studies suggest the use of anti-inflammatory drugs to reduce incidence of AD. However, clinical trials with anti-inflammatory drugs have not been successful.

  • Plasma amyloid beta levels and platelet mitochondrial respiration in patients with Alzheimer's disease.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-08
    Zdeněk Fišar,Roman Jirák,Martina Zvěřová,Vladimír Setnička,Lucie Habartová,Jana Hroudová,Zdislava Vaníčková,Jiří Raboch

    OBJECTIVES Altered amyloid metabolism and mitochondrial dysfunction play key roles in the development of Alzheimer's disease (AD). We asked whether an association exists between disturbed platelet mitochondrial respiration and the plasma concentrations of Aβ40 and Aβ42 in patients with AD. DESIGN AND METHODS Plasma Aβ40 and Aβ42 concentrations and mitochondrial respiration in intact and permeabilized platelets were measured in 50 patients with AD, 15 patients with vascular dementia and 25 control subjects. A pilot longitudinal study was performed to monitor the progression of AD in a subgroup 11 patients with AD. RESULTS The mean Aβ40, Aβ42 and Aβ42/Aβ40 levels were not significantly altered in patients with AD compared with controls. The mitochondrial respiratory rate in intact platelets was significantly reduced in patients with AD compared to controls, particularly the basal respiratory rate, maximum respiratory capacity, and respiratory reserve; however, the flux control ratio for basal respiration was increased. A correlation between the plasma Aβ42 concentration and mitochondrial respiration in both intact and permeabilized platelets differs in controls and patients with AD. CONCLUSIONS Based on our data, (1) mitochondrial respiration in intact platelets, but not the Aβ level itself, may be included in a panel of biomarkers for AD; (2) dysfunctional mitochondrial respiration in platelets is not explained by changes in plasma Aβ concentrations; and (3) the association between mitochondrial respiration in platelets and plasma Aβ levels differs in patients with AD and controls. The results supported the hypothesis that mitochondrial dysfunction is the primary factor contributing to the development of AD.

  • Search for biomarkers of Alzheimer's disease: Recent insights, current challenges and future prospects.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-04-07
    Kateřina Hrubešová,Markéta Fousková,Lucie Habartová,Zdeněk Fišar,Roman Jirák,Jiří Raboch,Vladimír Setnička

    Due to the trend of prolonged lifespan leading to higher incidence of age-related diseases, the demand for reliable biomarkers of dementia rises. In this review, we present novel biomarkers of high potential, especially those found in blood, urine or saliva, which could lead to a more comfortable patient experience and better time- and cost-effectivity, compared to the currently used diagnostic methods. We focus on biomarkers that might allow for the detection of Alzheimer's disease before its clinical manifestations. Such biomarkers might be helpful for better understanding the etiology of the disease and identifying its risk factors. Moreover, it could be a base for developing new treatment or at least help to prolong the presymptomatic stage in patients suffering from Alzheimer's disease. As potential candidates, we present, for instance, neurofilament light in both cerebrospinal fluid and blood plasma or amyloid β in plasma. Above all, we provide an overview of different approaches to the diagnostics, analyzing patient's biofluids as a whole using molecular spectroscopy. Infrared and Raman spectroscopy and especially chiroptical methods provide information not only on the chemical composition, but also on molecular structure. Therefore, these techniques are promising for the diagnostics of Alzheimer's disease, as the accumulation of amyloid β in abnormal conformation is one of the hallmarks of this disease.

  • 更新日期:2019-11-01
  • Choosing the best statistical method for reference interval estimation.
    Clin. Biochem. (IF 2.43) Pub Date : 2019-06-15
    V Higgins,S Asgari,K Adeli

  • Real-time reverse transcription loop-mediated isothermal amplification for rapid and simple quantification of WT1 mRNA.
    Clin. Biochem. (IF 2.43) Pub Date : 2009-03-20
    Soji Morishita,Hidenori Tani,Shinya Kurata,Kazunori Nakamura,Satoshi Tsuneda,Yuji Sekiguchi,Naohiro Noda

    OBJECTIVES This study developed a novel MRD monitoring method targeting Wilms' tumor gene (WT1) mRNA using reverse transcription loop-mediated isothermal amplification (RT-LAMP). DESIGN AND METHODS A primer set for the assay was designed on the basis of the sequences between the 17AA and KTS regions of WT1mRNA. WT1 mRNA was quantified by real-time RT-LAMP and the accuracy of RT-LAMP was compared with that of real-time RT-PCR. RESULTS The standard curve was expressed as a linear relationship between the log copy numbers of WT1 mRNA ranging from 6.8 x 10 to 6.8 x 10(9) copies and the threshold time with a correlation coefficient of R(2) > 0.994. The measured values obtained by RT-LAMP strongly correlated with those obtained by real-time RT-PCR. CONCLUSION RT-LAMP can be used to determine WT1 mRNA expression levels. This assay will contribute to a more specific, simple, and rapid MRD monitoring than conventional assays.

  • The urinary steroid profile in patients diagnosed with adrenal incidentaloma.
    Clin. Biochem. (IF 2.43) Pub Date : 2009-03-20
    Alicja Kotłowska,Edmund Maliński,Krzysztof Sworczak,Jolanta Kumirska,Piotr Stepnowski

    OBJECTIVE The aim of this study was to investigate the possible urinary markers of hormonal activity in patients with non-functioning adrenal incidentalomas. In order to evaluate the endocrine activity of aforementioned tumours, urinary steroid metabolite levels were analyzed in samples from patients and controls. Possible blocks in metabolic pathways of the examined hormones were determined by comparing selected urinary steroid metabolite sums and ratios in both groups of interest. DESIGN Urine samples were collected from 20 patients with non-functioning adrenal incidentalomas and from 25 controls matched in terms of age, sex and BMI. Excretion of 19 major urinary steroid metabolites was analyzed by gas chromatography. The results were subjected to statistical analysis. RESULTS In patients with adrenal incidentalomas sum of total urinary cortisol metabolites was significantly increased in respect to the control group. We also observed a shift towards tetrahydrocorticosterone, cortisol and etiocholanolone production in patients. No significant differences in production of other urinary steroid metabolites were noted in patients with adrenal incidentalomas in respect to control group. CONCLUSIONS Our data suggests that not only urinary free cortisol but also its metabolite such as tetrahydrocortisol and other steroids including etiocholanolone and corticosterone tetrahydrometabolite might be urinary markers for the endocrine activity of adrenal incidentalomas. Enhanced levels of these urinary steroid metabolites indicate an impairment of 11beta-hydroxysteroid dehydrogenase activity and slightly increased activity of 5beta-reductase in patients with adrenal incidentalomas.

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