Chitotriosidase: a sensitive biomarker of sarcoidosis

Chitotriosidase is a member of family of glycosylhydrolases, enzymes involved in the degradation of chitin and chitin-like substrate, identified in a wide variety of organisms. Increased concentrations of chitotriosidase have been reported in several lysosomal storage diseases and more recently also in sarcoidosis. In this study chitotriosidase concentrations were evaluated in a population of 233 sarcoidosis patients and 70 controls in order to verify enzyme specificity and sensibility and to evaluate chitotriosidase prognostic meaning. Chitotriosidase has been found significantly increased in serum of patients with sarcoidosis than in controls (p< 0.0001). ROC curve analysis revealed: cut-off value of 39.50 nmol/h/ml, sensitivity 89,70% and specifity 90%. The analysis of chitotriosidase in different phenotypic subgroups of patients revealed very high serum enzyme levels in symptomatic patients requiring systemic steroid therapy at onset and after disease relapses. In conclusion as a new potential biomarker of sarcoidosis severity, chitotriosidase resulted sensitive, reproducible and easily detectable in serum.