Increased cerebrospinal fluid chitotriosidase index in patients with multiple sclerosis

Objective - To investigate chitotriosidase (CTTS) activity in serum and cerebrospinal fluid (CSF) in multiple sclerosis (MS) patients in relation to disease course and CSF markers for immune activation or inflammation. Materials and methods - We studied 80 patients with relapsing-remitting MS (RRMS), 24 with secondary progressive MS (SPMS), 20 with primary progressive MS (PPMS) and 29 patients with other neurological disorders (OND). We measured CTTS activity and studied the correlation with CSF mononuclear cell count (MNC) and intrathecal IgG production. Results - CTTS activity was significantly higher in CSF, but not in serum, from the total MS group compared with OND and controls. In RRMS and SPMS CTTS, index was increased compared with controls (RRMS, 0.10 +/- 0.21; SPMS, 0.10 +/- 0.15; controls, 0.021 +/- 0.020), but not in PPMS (0.061 +/- 0.052). CTTS index was higher in MS patients with elevated MNC or CSF-restricted oligoclonal IgG bands than in MS patients without these CSF findings. Conclusions - CTTS index is elevated in RRMS and SPMS. The CTTS index is related to CSF markers of inflammation or immune activation.