Humoral immune response to individual Yersinia enterocolitica antigens in patients with and without reactive arthritis.

The IgG, IgA and IgM antibody responses to individual Yersinia enterocolitica antigens were analysed by immunoblotting in 10 patients with reactive arthritis and 11 patients with enterocolitis caused by Y. enterocolitica serotype 0:3. The IgG antibody response was directed against partly different antigens compared with IgA. The expression of these antigens varied with bacterial culture conditions. The IgG and IgM antibody responses in the early stages of infection (less than or equal to 3 weeks) were directed against a large number of antigens. The IgA response was more selective, with antibodies against 240, 48 and 34.5 kD antigens dominating. IgA antibodies against eight antigens ranging in molecular weight from 52.5 to 105 kD were seen exclusively among arthritic patients. When following the IgA antibody response in the two groups of patients for up to 993 days, antibodies tended to persist to selective antigens. However, these antigens varied to some extent between patients, but the persistence was seen both among arthritic and non-arthritic patients. Persistent antibodies to 240, 48 and 34.5 kD antigens were most common. IgA antibodies to a 112 kD antigen were more prevalent and persisted longer in patients with arthritis compared to patients with uncomplicated infection.