A Rare Case of Parvovirus Infection Causing Pure Red Cell Aplasia in a Kidney-Pancreas Transplant Recipient

Parvovirus B19 infection can rarely manifest with pure red cell aplasia in immunocompromised hosts. This case details a 48-year-old male, 11 years post kidney-pancreas transplant who was admitted with a chronic normocytic anaemia (haemoglobin 72 g/L) after being admitted four months prior with a bleeding peptic ulcer, requiring eight units of packed red blood cells. In the following months, the recipient required eight further packed red blood cell units despite normal repeat upper and lower gastrointestinal endoscopies. He had normal haematinics, with a persistent reticulocytopenia (0.3%, 7 × 10⁹ cells/L) despite 80 μg per week of subcutaneous darbepoetin alfa. Platelet and leukocyte counts were within normal limits. Parvovirus B19 polymerase chain reaction (PCR) test result was "detected" with a low cycle threshold (Ct) value of 13 generated by real-time PCR (RT-PCR). Transfusion-transmitted parvovirus was considered due to temporal association with recent blood products, but retrospective testing demonstrated that parvovirus serology and PCR results were "not detected" pre-transfusion; and that the first "detected" PCR result occurred following the first packed red blood cell transfusion. Australian Red Cross Lifeblood was notified, and lookback investigations excluded the blood products as a route for parvovirus transmission, postulating that community acquisition was most likely. High dose intravenous immunoglobulin (IVIG total 400 mg/kg/day over 5 days) and immunosuppression reduction led to haemoglobin stability to > 80 g/L over 14 days. Treatment response was further extrapolated by a parvovirus PCR cycle threshold increase to 25, 7 days after first IVIG dose in the absence of gold standard quantitative PCR testing unavailability.