Parvovirus B19 microepidemic in renal transplant recipients with thrombotic microangiopathy and allograft vasculitis.

Parvovirus B-19 (B-19) can lead to various clinical scenarios in renal transplant recipients. Here, we report a B-19 microepidemic that occurred between January and March 2007, involving renal transplant recipients from a single center in Tabriz, Iran. We observed 6 patients in whom there was a temporal association between active B-19 infection and thrombotic microangiopathy and intrarenal small and medium-sized vessel vasculitis. Patients typically presented with deteriorating renal allograft function and anemia, and laboratory findings revealed thrombotic microangiopathy. Ultimately, extensive endothelial injury and renal allograft vasculitis that mimicked a vascular rejection ensued. In conclusion, B-19-related thrombotic microangiopathy may precede allograft vasculitis in renal transplant recipients. A high index of suspicion is required for early diagnosis and treatment of B-19 infection. To the best of our knowledge, this series represents the first report of B-19-related renal allograft vasculitis in the English literature.