HLA-DR4 is not a requisite for autoimmunity to collagen in rheumatoid arthritis.

Immunogenetic studies in rheumatoid arthritis have demonstrated an increased frequency of the HLA-DR4 alloantigen in individuals with both the sporadic and familial forms of the disease. To investigate the significance of this association, we ascertained whether the possession of DR4 is necessary for the expression of cellular and humoral immunity to native human type II collagen. Our results indicate that the presence of DR4 is not required for the development of autoimmunity to collagen in rheumatoid arthritis.