A model for disease heterogeneity in systemic lupus erythematosus. Relationships between histocompatibility antigens, autoantibodies, and lymphopenia or renal disease.

We composed a model from autoimmune serologic findings, HLA antigens, and clinical findings that explains, at least partially, the clinical heterogeneity of 40 patients with systemic lupus erythematosus (SLE). In these patients, anti-RO (SS-A) was related to the HLA-DQ1/DQ2 heterozygotes, anti-La (SS-B) was related to HLA-B8 and HLA-DR3, and anti-nuclear RNP (Sm) was related to HLA-DR4. Lymphopenia was associated with anti-Ro (SS-A) and, secondarily, with anti-single-stranded DNA. Renal disease in these SLE patients was inversely associated with anti-La (SS-B) and was positively associated with anti-double-stranded DNA. There were no associations between the HLA antigens and these clinical manifestations. The results support a model of disease expression in which individuals are nonspecifically potentiated for SLE. Their HLA antigen composition influences the production of particular autoantibodies that are related in complex ways to the different particular clinical findings of SLE manifested in individual patients.