Recurrent Parvovirus B19 Infection in Pediatric Heart Transplant Recipients

Introduction Parvovirus B19 viremia has been reported as a cause of recurrent anemia in solid organ transplant (SOT) recipients. Many pediatric reports of this occurrence have been described in kidney transplant recipients, but less is known about this phenomenon in other pediatric SOT recipients. Furthermore, how immunosuppression may affect this outcome and how to manage chronic viremia remain to be studied. Case Presentation Here, we present a case series of three pediatric patients at a single institution (patients A, B, and C) who underwent orthotopic heart transplantation after which they developed parvovirus B19 viremia associated with recurrent episodes of aplastic anemia. Each patient required heart transplantation for dilated cardiomyopathy. Age at initial transplant ranged from 1 month, 19 days (patient A) to 6 months, 8 days (patient B). Patients A and B were both on tacrolimus and sirolimus dual therapy for immunosuppression, while patient C was on tacrolimus and mycophenolate for immunosuppression. The average time to parvovirus viremia was 133 months (range: 124 months in patient B to 142 months in patient C). Patient A had two anemic crises due to high parvovirus B19 viral load, while patients B and C had three each. Each anemic crisis was managed with red blood cell transfusion and high-dose intravenous immunoglobulin therapy. In each case, all patients were unable to make specific parvovirus IgG responses following infection. Patient A had previously been on a long-standing immunoglobulin replacement therapy with acute anemic crises attributed to lapses in therapy. While on immunoglobulin replacement, patient A has had no further crises. Notably, patients A and C also had long-standing severe CD4+ and CD8+ T cell lymphopenia, while patient B had normal enumeration of lymphocyte subsets. Discussion Parvovirus B19 infection is a serious cause of morbidity and need for hospitalization and blood product transfusion among SOT recipients. Time to first infection and number of anemic crises may be influenced by the mode of immunosuppression. Immunosuppression may also affect class switching and production of an effective IgG antibody response following infection. As such, chronic immunoglobulin replacement therapy may be a viable option for management of parvovirus B19 viremia in SOT recipients.