BK Virus–Associated Hemorrhagic Cystitis in a Human Immunodeficiency Virus–Infected Patient

BK virus-associated hemorrhagic cystitis is a common clinical problem in bone marrow transplant recipients but is considered rare in other immunosuppressed patient populations. We describe a human immunodeficiency virus-infected patient with non-Hodgkin's lymphoma in whom BK virus-associated hemorrhagic cystitis developed; viruria was quantitated in urine by immunocytochemistry, and the patient showed no response to cidofovir.