Autoimmunity in rheumatoid arthritis. An approach via a study of B lymphocytes.

In this article the relationship between the cellular elements of the immune response and inflammation are examined with reference to the B lymphocyte repertoire. Evidence is presented that, in addition to an environment in the joint that favors localization and activation of auto-reactive B lymphocytes, the circulating B lymphocyte pool in rheumatoid arthritis is abnormally enriched in cells that bear a receptor for mouse erythrocytes and possess CD5 antigen. B lymphocytes with these novel phenotypic markers secrete autoantibodies and are found in abundance in fetal lymphoid tissues and cord blood; analogous cells in the mouse belong to a distinct lineage and are implicated in allotype- and idiotype-restricted interactions. It is postulated that a subset of B lymphocytes is of primary importance in the etiopathogenesis of rheumatoid disease.