Association of cerebrospinal fluid IgM index with central nervous system involvement in Behçet's disease.

Immunoglobulin (IgM, IgA, and IgG) and albumin values were determined in 12 patients who had signs and symptoms of central nervous system involvement attributable to Behçet's disease. Only the cerebrospinal fluid IgM index, which was significantly elevated in patients with active neuro-Behçet's syndrome, was found to decrease when the neurologic manifestations of the disease had disappeared. This indicates that determination of this index may be of help in the evaluation of central nervous system disease activity in neuro-Behçet's syndrome.