Effects of Azathioprine and Mycophenolate Mofetil—Immunosuppressive Regimens on the Erythropoietic System of Renal Transplant Recipients

Azathioprine (AZA) and mycophenolate mofetil (MMF) are major immunosupressants used to prevent rejection following renal transplantation. Bone marrow suppression is a potential adverse effect of these agents manifesting itself as leukopenia, thrombocytopenia, and anemia. The aim of this study was to compare the effects of AZA versus MMF immunosuppressive regimens on the erythropoietic system of renal transplant recipients within 6 months after transplantation. Eighty kidney allograft recipients who were on AZA ( n = 40) or MMF ( n = 40) plus cyclosporine and prednisolone were enrolled in this study. Hematologic parameters included red blood cell counts, hemoglobin (Hb), hematocrit, mean corpuscular volume, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) and were measured before and at 1 week, as well as 1 and 6 months posttransplantation. Plasma erythropoietin level was measured at the end of 6 months. Statistical analysis was performed with Student t test; a P value less than .05 was considered significant. There was no significant difference between the two groups regarding red blood cell counts. High Hb level was noted at 1 and 6 months posttransplantation among patients who received MMF. MCH and MCHC were higher among patients on MMF compared with those on AZA at 1 week and 1 month posttransplant. Although the mean plasma erythropoietin levels in AZA-treated patients were higher than those of MMF-treated patients, the trend did not reach statistical significance ( P = .066). MMF administration was apparently associated with a higher level of hemoglobin compared with AZA among renal allograft recipients with good graft function at 6 months posttransplantation.