INTRATHECAL SYNTHESIS OF FREE IMMUNOGLOBULIN LIGHT-CHAINS IN MULTIPLE-SCLEROSIS

Objective - The detection of oligoclonal immunoglobulin free light cha ins (FLC) in the diagnosis of multiple sclerosis (MS) was compared to IgG isoelectric focusing. Material ann methods - Cerebrospinal fluid a nd serum samples from 69 patients with possible first attacks of MS, 5 0 patients with clinically definite MS (CDMS), and 118 patients with o ther neurological diseases (OND) were analyzed. IgG and FLC oligoclona l bands were detected by isoelectric focusing and immunoperoxidase sta ining. Results - Intrathecal synthesis of IgG, kappa FLC, and lambda F LC oligoclonal bands, respectively, was seen in 92%, 92%, and 86% of M S patients; in 61%, 62%, and 64% of patients with possible first attac ks of MS; and in 3%,3%, and 8% of the patients with OND. In control pa tients without IgG synthesis intrathecal lambda FLC synthesis was more common than kappa FLC synthesis (P=0.03). Conclusion - Kappa FLC dete ction proved as useful as IgG analysis for the laboratory diagnosis of MS whereas the presence of intrathecal lambda FLC synthesis was less specific.