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 patients studied. Circulating autoantibodies were an independent predictor of anemia (odds ratio [OR]=5.0; 95% confidence interval [CI], 2.5-9.9), as strong as other known causes of anemia. The association of anti-EPO antibodies with anemia became stronger when the analysis was limited to the group of 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 were associated with higher EPO levels (r=.25, P=.012) and with a more prominent EPO response to anemia. Our findings suggest that autoimmunity, among other factors, may contribute to the pathogenesis of HIV-1-related anemia.