Case report: immunoglobulin A deficiency in patients with juvenile rheumatoid arthritis treated with aspirin.

In three patients with juvenile rheumatoid arthritis, serum IgA concentrations were within the normal limit at the onset of disease and before aspirin administration. After aspirin administration, their serum IgA levels gradually decreased. After discontinuation of aspirin, their serum IgA levels gradually increased. These results suggest that IgA deficiency may be due to aspirin administration in such patients. The IgA production in vitro of peripheral blood mononuclear cells from a patient taken 3 months of discontinuation of aspirin was markedly inhibited by preincubation with aspirin. Since the patients' serum IgG and IgM levels hardly changed the heavy chain class switching may be influenced by aspirin through some undefined mechanisms.