BACKGROUND Serum chitotriosidase is a promising biomarker that has shown high specificity and sensitivity in patients with sarcoidosis. The aim of this study was to investigate correlations between serum chitotriosidase, clinical phenotypes, disease localizations and different radiological lung involvement and to identify clinical features associated with over-expression of chitotriosidase in a large cohort of sarcoidosis patients. METHODS Chitotriosidase activity was evaluated in a population of 694 consecutive patients (males 39%, age 55.8 ± 12.8 years). Clinical and respiratory functional characteristics, Clinical Outcome Scale (COS) classification, clinical phenotypes proposed by the GenPhenResA project, and radiological assessment, including CT scan, were collected. Serum sampling and clinical and functional assessments at follow-up were also included. RESULTS Significantly higher chitotriosidase activity was observed in sarcoidosis patients than in healthy controls (p < 0.0001). Evidence of lung fibrosis with reticular abnormalities and traction bronchiectasis at High resolution CT, presence of multiple extrapulmonary sarcoid localizations and increased 24-h urinary excretion of calcium were associated with significantly higher chitotriosidase activity (p < 0.005). Patients with remitted or minimal disease had lower values of chitotriosidase than patients with persistent disease. At follow-up, patients who required an increase in steroid dose showed an increase in its activity. CONCLUSIONS Chitotriosidase is a reliable biomarker of sarcoidosis. It is increased in patients with sarcoidosis correlating with disease activity, severity and multiorgan dissemination. Steroid therapy tended to reduce chitotriosidase expression, however it responded in cases of disease relapse.

中文翻译：

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壳三糖苷酶：结节病患者活动和严重程度的生物标志物。

背景技术血清壳三糖苷酶是一种有前途的生物标志物，在结节病患者中已显示出高特异性和敏感性。这项研究的目的是调查在大型结节病患者队列中血清壳三糖苷酶，临床表型，疾病部位和不同的放射性肺受累之间的相关性，并确定与壳三糖苷酶过度表达相关的临床特征。方法对694名连续患者（男性39％，年龄55.8±12.8岁）中的壳三糖苷酶活性进行了评估。收集了临床和呼吸功能特征，临床结果量表（COS）分类，GenPhenResA项目提出的临床表型以及包括CT扫描在内的放射学评估。随访时还包括血清采样以及临床和功能评估。结果结节病患者的壳三糖苷酶活性明显高于健康对照组（p <0.0001）。高分辨率CT显示肺纤维化伴网状异常和支气管扩张，伴有肺外结节状多发以及钙24小时尿排泄增加，与壳三糖苷酶活性显着升高相关（p <0.005）。与持续疾病患者相比，疾病缓解或轻微患者的壳三糖苷酶值较低。在随访中，需要增加类固醇剂量的患者表现出其活性增加。结论壳三糖苷酶是结节病的可靠生物标志物。在结节病患者中，与疾病活动性，严重程度和多器官传播相关的患者中，其增加。类固醇疗法倾向于降低壳三糖苷酶的表达，但是在疾病复发的情况下它可以缓解。