BK Polyomavirus-Induced Nephropathy in Native Kidney.

BK polyomavirus has been well-studied as an opportunistic infection in immunocompromised kidney transplant patients. In the majority of the population, BK polyomavirus establishes a lifelong infection in renal tubular and uroepithelial cells; however, in an immunocompromised state, the virus can reactivate and can lead to BK polyomavirus-associated nephropathy (BKN). In this case, the patient was a 46-year-old male with a past medical history of HIV, compliant with antiretroviral therapy (ART), and B-cell lymphoma treated with chemotherapy. The patient presented with worsening kidney function of unknown etiology. This prompted further assessment with a kidney biopsy. Kidney biopsy findings were consistent with BKN. In the literature, BKN has been studied in renal transplant patients; however, it rarely involves native kidneys.