Tacrolimus, a forgotten agent in kidney transplant leukopenia

Leukopenia in kidney transplant patients is frequent, it causes potentially life-threatening complications, but it is often poorly characterized. Opportunistic infections, immunologic disturbances and drug-related toxicity are principal causes of single or multilineage cytopenias. Tacrolimus-induced leukopenia is a less recognized but frequent complication. We describe one patient with leukopenia developing within seven months after renal transplant. After excluding other potential causes, tacrolimus was switched to cyclosporine, with recovery of white blood cell count. Based on the clinical report, the authors reviewed causes of post-transplant leukopenia, focusing on the diagnostic investigation. Early diagnosis and interventions are fundamental to improve prognosis.