Effects of erythropoietin treatment on cell-mediated immune responses in predialysis patients

The effects of erythropoietin (EPO) treatment on the immune functions of dialysis patients have been shown to be controversial and there are only limited data concerning predialysis patients.

Twenty-four predialysis patients with renal anemia were assigned to subcutaneous EPO treatment, and those in need (n=19) were additionally treated with i.v. iron every other week. We analyzed the effect of the start of EPO treatment on (i) lymphocyte and lymphocyte subclass counts, (ii) lymphocyte stimulation functions and (iii) persisting IgG-class antibody levels to the viral antigens of Epstein-Barr virus and cytomegalovirus.

Our main findings were a decrease in the absolute lymphocyte count, combined with decreases in all the main lymphocyte subclass counts. The absolute number of cells with activation and memory markers remained constant, and therefore their proportion slightly increased. The proliferation responses to phytohemagglutinin, tuberculin and tetanus declined significantly, while the amount of IgG-class viral antibodies remained unchanged, meaning that the humoral side of immunity was not affected by the start of the EPO treatment. Similarly, the proliferation response to pokeweed mitogen, a B-cell mitogen, was unchanged.

EPO treatment has a suppressive effect on cellular immune functions of predialysis patients. This suppression does not correlate with erythropoiesis, kidney function or iron status.