Immunogenetic markers in rheumatic diseases.

Certain genetic markers in the major histocompatibility complex have been associated with increased risk of developing ankylosing spondylitis, rheumatoid arthritis, and systemic lupus erythematosus. These markers, however, do not appear in all patients with these diseases, suggesting that other gene products or environmental factors may play a role in disease expression. Current investigations using monoclonal antibody and peptide mapping techniques suggest that many gene products share similar protein sequences with known disease susceptibility genetic markers.