[Oligoclonal aspects of IgG of the cerebrospinal fluid. Methods of analysis and clinical correlations].

Intrathecal synthesis of immunoglobulins is analyzed by two methods: quantitatively by immunoglobulin titration (IgG index) in cerebrospinal fluid (CSF) and qualitatively by demonstration of oligoclonal distribution of gammaglobulins. The authors report the results of a comparative study evaluating the IgG index and agarose electrophoresis versus electrofocusing. Sensitivity of electrofocusing was higher than the IgG index of standard agarose electrophoresis. Electrofocusing is the best method of proving intrathecal synthesis of immunoglobulins. Although oligoclonal bands are a useful aid in the diagnosis of multiple sclerosis, they indicate an immunological response but are not diagnostic for a particular disease.