Does tacrolimus cause more severe anemia than cyclosporine A in children after renal transplantation?

Understanding renal posttransplantation anemia in the pediatric population

Advances in renal transplantation management have proven to be beneficial in improving graft and patient survival. One of the properties of a well-functioning renal allograft is the secretion of adequate amounts of the hormone erythropoietin to stimulate erythropoiesis. Posttransplantation anemia (PTA) may occur at any point in time following transplantation, and the cause is multifactoral. Much of our understanding of PTA is based on studies of adult transplant recipients. The limited number of studies that have been reported on pediatric renal transplant patients appear to indicate that PTA is prevalent in this patient population. Erythropoietin deficiency or resistance is commonly associated with iron deficiency. An understanding of the risk factors, pathophysiology and management of PTA in the pediatric renal transplant population may provide guidelines for clinicians and researchers in the pursuit of larger prospective randomized control studies aimed at improving our limited knowledge of PTA. Recognition of PTA through regular screening and evaluation of the multiple factors that may contribute to its development are recommended after transplantation.

Bone marrow hypoplasia complicating tacrolimus (FK506) therapy

Tacrolimus (FK506)-induced hematological toxicity, which has rarely been reported in transplant recipients, may result in anemia episodes, reported mainly in kidney and heart transplant recipients, sporadic cases of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, red cell aplasia (4 reported cases), and generalized bone marrow suppression (only 1 reported case). We describe a case of a liver transplant recipient with pancytopenia that appeared during immunosuppressive therapy with tacrolimus. This patient suffered from progressive anemia, leukopenia with severe neutropenia, and mild thrombocytopenia; bone marrow biopsy showed hypoplasia (20% of cellularity) without dysplasia. Bone marrow recovery was made possible by suspending tacrolimus and changing to immunosuppression with cyclosporine A, despite the two drugs being very similar in their mechanism of immunosuppression. Contrary to previously reported cases (pure red cell aplasia and bone marrow hypoplasia), the recovery of hemoglobin and neutrophil values was slow after tacrolimus suspension, even though in the first month transfusions were no longer necessary.