Humoral and cellular immunologic aspects of adjuvant and collagen arthritis in rats

Systemic and local immunological responses of rats sensitized with either M. butyricum or native type II collagen have been evaluated. In rats exhibiting adjuvant-induced arthritis no antibodies to collagen could be detected. In animals exhibiting collagen-induced arthritis, high antibody titers developed by day 14, and could be correlated with the severity of the arthritis. Delayed type hypersensitivity (DTH) responses were measured by a 5-iodo-2'-deoxyuridine 125-I (125-IUdR) uptake assay. Arthritic scores in rats immunized with collagen were not accompanied by a positive DTH response, whereas adjuvant arthritic rats showed a positive response. T-lymphocyte cellular responses in both adjuvant- and collagen-induced arthritic rats were measured. In neither syndrome were major alterations observed in T-lymphocyte subpopulations. These results provide evidence that adjuvant-induced arthritis and type II collagen-induced arthritis are distinct entities, and that they may be discriminated by the nature of the humoral response.