CSF "monoclonal" bands in chronic relapsing polyneuropathy.

The characteristics and temporal profiles of cerebrospinal fluid (CSF) and serum immunoglobulin patterns on agarose gel electrophoresis were studied in 47 patients with acute idiopathic polyneuropathy (AIP) and 15 patients with chronic relapsing polyneuropathy (CRP). Nineteen of 47 patients with AIP had transient oligoclonal IgG bands, which disappeared when the neurologic signs subsided. By contrast, 14 of 15 patients with CRP had a "monoclonal" (single) IgG band, which (1) was unchanged on repeated CSF examinations over 18 months, (2) was unaffected by corticosteroid therapy, and (3) did not correlate with the severity or chronicity of the disease. Serum protein patterns and in situ central nervous system IGG synthesis and IgG:albumin index were normal in the CRP patients. The origin of the band and the nature of the putative antigen(s) that the band may be directed against were not identified. Our findings suggest that different immunopathogenic mechanisms may be operating in CRP, compared with AIP. The stable IgG band in CRP may reflect response to a persisting antigenic stimulation and, with further experience, may prove to be of prognostic significance by furnishing early in the illness: (1) a clue to the subsequent course of the disease, and (2) possible guidance on therapeutic decisions.