[The content of free light-chain immunoglobulins in the cerebrospinal fluid and the importance of its determination for the differential diagnosis of multiple sclerosis].

The serum and liquor of 70 patients with multiple sclerosis (MS), 54 patients with other neurological diseases and 20 controls were examined for free light chains (FLC) of immunoglobulins type chi and lambda. The findings were compared to blood-brain barrier competence, liquor pleocytosis, IgG intrathecal synthesis 86% MS patients exhibited high levels of liquor chi-type FLC which appeared early in the disease course irrespectively of MS phase and pattern. Simultaneous high content of lambda-type FLC was reported in 52% of the cases. Patients in need of differential diagnosis were characterized by normal or reduced (in spinocerebellar ataxia) concentrations of FLC except for the conditions with impaired blood-brain barrier.