Long-term effects on lymphocytotoxic antibodies and immune reactivity in hemodialysis patients treated with recombinant human erythropoietin.

Twenty-six hemodialysis patients were given human recombinant erythropoietin to correct anemia. Eighteen patients had previously received multiple transfusions and 18 had been transfused within the preceding six months. Ten patients had lymphocytotoxic antibodies (panel reactive antibodies, PRA), measured as percent positive reactions against a panel of lymphocytes from 22 lymphocyte donors before the start of erythropoietin treatment. There was a significant decrease in mean PRA activity from 60% to 35% (p less than 0.05) during 6-18 months of treatment. Three of 26 patients received blood transfusions after the start of erythropoietin treatment, because of intercurrent disease or blood loss. Kidney transplantation was performed in four of the PRA-positive patients and in eight of the PRA-negative patients. Nine kidney transplants are currently functioning. The three graft losses were due to rejections. The lymphocyte immune reactivity measured after stimulation in MLC (mixed lymphocyte culture) against pooled lymphocytes and after PHA (phytohemagglutinin) and Con A (Concanavalin A) stimulation, was significantly lower in the hemodialysis patients than in the healthy controls (p less than 0.05). The responses did not change after correction of anemia. The number of OKM1 (Ortho's monoclonal antibody against M1 cells [monocytes])-positive cells among peripheral blood lymphocytes were significantly higher (p less than 0.001) in uremic patients than in healthy controls. After 12-18 months of treatment with erythropoietin this difference disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)