Parvovirus B19 infection causing red cell aplasia in renal transplantation on tacrolimus.

Parvovirus B19 infection is known to cause chronic anemia in immunocompromised hosts, including organ transplant recipients. Most reported cases of parvovirus B19-associated aplastic anemia in renal transplant recipients responded to intravenous immunoglobulin (IVIG) infusion. Tacrolimus is of special interest; it was proposed to be associated with pure red cell aplasia (PRCA) on its own because resolution of anemia on withdrawal of tacrolimus was previously observed. Interaction between parvovirus B19 infection and tacrolimus has not been reported. We report a case of parvovirus B19-associated PRCA in a renal transplant recipient treated with tacrolimus who failed to clear the virus despite repeated courses of IVIG. She showed complete recovery promptly after tacrolimus was switched to cyclosporine A. A well-documented concomitant decrease in serum parvovirus DNA polymerase chain reaction titer was also observed. This shows another mechanism by which tacrolimus can aggravate PRCA because of impaired clearance of parvovirus B19 infection in transplant recipients. For those patients receiving tacrolimus who have parvovirus B19 infection with refractory anemia and who fail to recover with IVIG, replacement of tacrolimus with cyclosporine A can be considered.