Cyclophosphamide exposure pretransplant is associated with complications in the first year after kidney transplant.

OBJECTIVES Some patients needing a kidney transplant have used cyclophosphamide before the transplant. Long-term bone marrow damage associated with cyclophosphamide could manifest with myelotoxic complications after transplant in the context of the immunosuppressant, but evidence for this has not been published. MATERIALS AND METHODS We performed a retrospective, single-center analysis of renal transplant recipients with prior cyclophosphamide exposure and compared posttransplant short-term outcomes to a random control group (clinical outcomes identified by searching automated electronic databases). RESULTS Sixteen recipients had taken cyclophosphamide before the transplant and were compared with a control group of 32 patients. Hospitalization rates were equal, and although there were 3 times more hospitalizations secondary to an infective course in the cyclophosphamide group, this did not achieve significance (0.63 vs 0.22; P = .147). There was no difference in rates of bacteriuria, cytomegalovirus, or Polyomavirus. The cyclophosphamide group was at significantly greater risk of needing a blood transfusion immediately after the transplant (average number of units of blood per patient, 0.44 vs 0.19; P = .038). Also, they were 3 times more likely to require anemia treatments 1 year after the transplant (average number of anemia treatment medications, 0.75 vs 0.25; P = .014). Full blood count parameters, graft function, and graft and patient survival at 1 year posttransplant were equal. CONCLUSIONS Evidence suggests that pretransplant administration of cyclophosphamide is associated with adverse short-term outcomes posttransplant. Further analyses are warranted to investigate these preliminary findings to determine whether myelosuppressive immunosuppressant should be modified in the context of prior cyclophosphamide exposure.