Human kallikrein 6 cerebrospinal levels are elevated in multiple sclerosis

The protease, human kallikrein-related peptidase 6 (hK6) is derived from activated macrophages in the central nervous system (CNS) and may contribute to pathology observed in multiple sclerosis (MS). In the present study, we compared serum and cerebrospinal fluid (CSF) protein concentrations of human kallikrein-related peptidase 6 derived from neurological controls and patients diagnosed with advanced multiple sclerotic disease. Mean serum levels of human kallikrein-related peptidase 6 were similar in neurological controls and patients diagnosed with relapsing-remitting (RR), secondary progressive (SP) and primary progressive (PP) multiple sclerosis with mean levels ranging from 3.5 to 3.75 ng/ml. Patients diagnosed with advanced multiple sclerosis showed mean CSF levels (29 ng/ml) that were significantly higher than neurological controls (25.5 ng/ml). Determining CSF concentrations of human kallikrein-related peptidase 6 may therefore have diagnostic value in MS.