Lymphocytes subsets in osteoarthritis versus rheumatoid arthritis.

It has been suggested that osteoarthritis (OA) is induced by mechanical stress manifested by cartilage destruction with no or minimal involvement of the immune response as compared to that in rheumatoid arthritis (RA). This study is a trial to investigate the hypothesis that the immune response has a critical role in the pathogenesis of OA. This work was performed on 2 groups of patients: the first group included 20 primary OA knee patients and the second group included 18 RA patients as autoimmune controls.