Prognostic value of cerebrospinal fluid IgA and IgG in multiple sclerosis.

IgA antibodies do not activate complement and may compete with and protect against myelin degradation caused by IgM and IgG in multiple sclerosis (MS). We retrospectively evaluated cerebrospinal fluid (CSF) IgA and IgG (as indices and extended indices) from 1980 to 1988 in 68 patients with definitive MS. Sixty-one of them had survived since the time of sampling (11-19 years).