BACKGROUND The aim of the study was to investigate if speciation analysis by liquid chromatography coupled to mass spectrometry could be used to detect organic and inorganic binding forms of selenium in the cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD) and age-matched control subjects (AMC). METHODS PD patients and control subjects were enrolled from three different neurological departments. CSF samples were collected according to standardized biomarker protocols and subjected to inductively coupled plasma mass spectrometry (ICP-MS) for total selenium determination and ion exchange chromatography (IEC) hyphenated to ICP-MS for selenium speciation analysis. RESULTS 75 PD patients and 68 age-matched controls were enrolled for speciation analysis. 8 different species could be detected, but only selenoprotein P (SELENOP), human serum albumin-bound Se (Se-HSA), selenomethionine (Se-Met) and an unidentified Se-compound (U2) presented with more than 50% values above the limit of quantification, without showing significant differences between both groups (p > 0.05). The Se-HSA / Se-Met ratio yielded a significant difference between PD and AMC (p = 0.045). The inorganic species Se-IV and Se-VI were only detectable in a minor part of PD and AMC samples. A highly significant correlation between total selenium levels and SELENOP (PD p < 0.0001; AMC p < 0.0001) and Se-HSA (PD p < 0.0001; AMC p < 0.0001) could be demonstrated, respectively. CONCLUSIONS Speciation analysis yielded new insight into selenium homeostasis in PD but cannot be used to establish a diagnostic biomarker. The small number of detectable values for Se-IV and Se-VI suggests an inferior role of these potentially neurotoxic binding forms in PD pathology in contrast to other neurodegenerative disorders.

中文翻译：

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帕金森氏病患者脑脊液中硒的形态分析。

背景技术本研究的目的是研究通过液相色谱与质谱联用的形态分析是否可用于检测帕金森氏病（PD）和年龄匹配的患者的脑脊液（CSF）中硒的有机和无机结合形式对照对象（AMC）。方法来自三个不同神经科的PD患者和对照组。根据标准生物标志物协议收集CSF样品，然后进行电感耦合等离子体质谱（ICP-MS）进行总硒测定，将离子交换色谱法（IEC）连接到ICP-MS进行硒形态分析。结果纳入了75名PD患者和68名年龄匹配的对照进行形态分析。可以检测到8种不同的物种，但只有硒蛋白P（SELENOP），人血清白蛋白结合的硒（Se-HSA），硒代蛋氨酸（Se-Met）和未鉴定的硒化合物（U2）的含量超出定量限50％以上，而两组之间均无显着差异（p> 0.05）。Se-HSA / Se-Met比值在PD和AMC之间产生显着差异（p = 0.045）。只能在PD和AMC样品的一小部分中检测到无机物Se-IV和Se-VI。可以证明总硒水平与SELENOP（PD p <0.0001; AMC p <0.0001）和Se-HSA（PD p <0.0001; AMC p <0.0001）之间有极显着的相关性。结论形态分析对PD中的硒稳态产生了新的见解，但不能用于建立诊断性生物标志物。