Cholesterol levels in plasma and cerebrospinal fluid in patients with clinically isolated syndrome and relapsing-remitting multiple sclerosis.

Cholesterol is essential for myelin formation, but may also modulate mechanisms involved in adaptive immune responses. It is unclear whether lack of remyelination in multiple sclerosis (MS) results from an insufficient capacity of oligodendrocyte precursor cells to differentiate or from cholesterol insufficiency. Several studies have assessed the potential association of lipid profile and its metabolism with demyelination, disability, and disease progression. The aim of the present study was to measure cholesterol levels in plasma and cerebrospinal fluid (CSF) of patients with relapsing remitting MS (RRMS) or with clinically isolated syndrome (CIS), and to investigate whether there is an association between cholesterol levels and disease characteristics. Sixty-two patients with CIS and 46 patients with RRMS were included in the study. All patients had low EDSS and were medication-free at assessment. Forty-eight subjects within the same age range served as controls. Cholesterol concentrations were measured in plasma and in CSF by the same enzymatic - colorimetric method, and were related to clinical status, disease activity in magnetic resonance imaging (MRI) and presence of oligoclonal bands in CSF (OBs). Significantly lower levels of plasma and CSF cholesterol were found in patients compared to controls. Patients with OBs showed significantly lower levels of CSF cholesterol but not plasma cholesterol compared to OBs-negative patients. A positive correlation of plasma cholesterol with age and of CSF cholesterol with EDSS was found. Our results suggest that low CSF cholesterol in MS patients with positive OBs might reflect extensive demyelination and a more aggressive disease course associated with an increased humoral immune response against membrane components.