EVIDENCE THAT TREATMENT OF ESRD PATIENTS WITH RECOMBINANT-HUMAN-ERYTHROPOIETIN INDUCES IMMUNOSUPPRESSION WITHOUT AFFECTING THE DISTRIBUTIONOF PERIPHERAL-BLOOD MONONUCLEAR CELL SUBPOPULATIONS

Fifteen patients with end-stage renal disease (ESRD) were blood sample d before and 1-, 2-, 3-, and 6 months after institution of recombinant human erytropoietin (r-HuEPO) therapy. Subpopulations of immunocompet ent pheripheral blood mononuclear cells (PBMC) were analyzed by flow c ytometry using monoclonal antibodies against various T-lymphocyte anti gens, B-lymphocytes, natural killer (NK)-cells, monocytes, and macroph ages, and finally bone marrow progenitor cells. Functional properties of peripheral T-lymphocytes were analyzed by proliferation assays with mitogens, alloantigens and microbiological antigens. All patients but 3 responded with sufficient correction of the anaemia. The absolute n umber of leucocytes and lymphocytes remained unchanged during the stud y. Likewise, a remarkable intraindividual months to month constancy in the relative distribution of all PBMC subsets analyzed was recorded d uring the observation period, although some interindividual variabilit y was observed. In contrast, the T-lymphocyte responsiveness decreased significantly except for 2 out of 11. We conclude, that treatment of renal anemia with r-HuEPO seems to induce immunosuppression in ESRD pa tients without affecting the distribution of various PBMC subsets.