Persistent Parvovirus B19 Viremia Despite Repeated Intravenous Immunoglobulin Therapy After Kidney Transplantation: A Case Report.

Parvovirus B19 infection is an increasingly recognized opportunistic infection in kidney transplant recipients and should be considered in patients presenting with unexplained anemia after transplantation. We report the case of a 31-year-old kidney transplant recipient who developed Parvovirus B19 infection 27 days after transplantation. The patient presented with a flu-like syndrome, severe leukopenia, and erythropoietin-resistant anemia. Quantitative polymerase chain reaction revealed a viral load exceeding 10⁹ copies/mL. Intravenous immunoglobulin therapy was administered, resulting in hematological improvement. However, despite three courses of intravenous immunoglobulin therapy and prolonged reduction of immunosuppressive treatment, persistent Parvovirus B19 viremia was documented for approximately 40 months. During follow-up, donor-specific antibodies developed, and the kidney allograft biopsy demonstrated recurrent IgA nephropathy without evidence of rejection. Viral load progressively decreased to 280 copies/mL in December 2022 before becoming undetectable in January 2023, allowing progressive reintroduction of mycophenolate mofetil. This case highlights the challenges associated with achieving viral clearance in kidney transplant recipients with Parvovirus B19 infection and emphasizes the importance of long-term virological and immunological monitoring.