Circulating autoantibodies to erythropoietin are associated with human immunodeficiency virus type 1-related anemia

In a cohort of 204 unselected consecutive human immunodeficiency virus type 1 (HIV-1)-infected patients, the association of circulating autoantibodies to endogenous erythropoietin (EPO) with HIV-1-related anemia was studied. Circulating autoantibodies to EPO were present in 48 (23.5%) of the 204 pat ients studied. Circulating autoantibodies were an independent predictor of anemia (odds ratio [OR] = 5.0; 95% confidence interval [CI], 2.5-9.9), as s trong as other known causes of anemia. The association of anti-EPO antibodi es with anemia became stronger when the analysis was limited to the group o f patients without any medical condition causing anemia (OR = 10.4; 95% CI, 3.2-33.9). Moreover, the effect on hemoglobin levels remained significant even after adjusting for other anemia parameters. Anti-EPO autoantibodies w ere associated with higher EPO levels (r =.25, P =.012) and with a more pro minent EPO response to anemia. Our findings suggest that autoimmunity, amon g other factors, may contribute to the pathogenesis of HIV-l-related anemia .