Enteroviral-related antigen in circulating immune complexes of amyotrophic lateral sclerosis patients.

Circulating immune complexes were isolated by polyethylene glycol precipitation from the sera of patients with amyotrophic lateral sclerosis. Rabbits immunized with circulating immune complexes from 3 of 5 amyotrophic lateral sclerosis patients induced antisera that specifically reacted with enterovirus-infected cells by immunofluorescence and enzyme-linked immunosorbent assay. These antisera were nonneutralizing and did not react with purified virus. In addition, peripheral lymphocytes of amyotrophic lateral sclerosis patients produced lymphokine in response to extracts from enterovirus (Coxsackie B4) infected cells. These results suggest both a humoral (circulating immune complex) and a cellular immune response in some patients with amyotrophic lateral sclerosis to enterovirus-coded or -induced antigen.