Serologic subsets in systemic lupus erythematosus: an examination of autoantibodies in relationship to clinical features of disease and HLA antigens.

A search for anti-Ro or anti-nRNP antibodies by precipitin analysis among a population of 64 patients with systemic lupus erythematosus (SLE) or mixed connective tissue disease was undertaken. The 25% of SLE patients with anti-Ro did not have any distinct clinical features, compared to patients without anti-Ro or to anti-nRNP patients with SLE or mixed connective tissue disease. However, these patients did have a significantly greater frequency of rheumatoid factor (80%). Most importantly however, patients with anti-Ro had a significantly increased frequency of HLA-B8 (81%) and HLA-DRw3 (100%) compared to patients with anti-nRNP (B8--29%; DRw3--33%) or SLE patients without such antibodies (B8--41%; DRw3--25%). These data suggest the existence of a specific immune response gene for Ro close to the D region of the major histocompatibility complex.