Immunofluorescence studies in a case of rheumatoid neuropathy.

Findings in a sural nerve biopsy from a patient with rheumatoid neuropathy are reported. Inflammatory changes in different stages were observed in epineurial arterioles. Arterioles with fibrinoid necrosis contained IgG, IgM, rheumatoid factor and complement. The same substances were found at the inner site of the perineurial sheaths. It is suggested that these proteins leaked out of endoneurial vessels and became trapped in the perineurial sheaths. With anti-herpes simplex virus serum fluorescence was seen in monuclear cells of infiltrated vessel walls. This virus could not be isolated in tissue culture.