BACKGROUND/AIMS: BK virus (BKV) has been associated with late-onset hemorrhagic cystitis (HC) in recipients of hematopoietic stem cell transplantation (HSCT). Cidofovir has been used at higher doses (3 to 5 mg/kg/wk) with probenecid prophylaxis; however, cidofovir may result in nephrotoxicity or cytopenia at high doses. METHODS: Allogeneic HSCT recipients with BKV-associated HC are treated with 1 mg/kg intravenous cidofovir weekly at our institution. A microbiological response was defined as at least a one log reduction in urinary BKV viral load, and a clinical response was defined as improvement in symptoms and stability or reduction in cystitis grade. RESULTS: Eight patients received a median of 4 weekly (range, 2 to 11) doses of cidofovir. HC occurred a median 69 days (range, 16 to 311) after allogeneic HSCT. A clinical response was detected in 7/8 patients (86%), and 4/5 (80%) had a measurable microbiological response. One patient died of uncontrolled graft-versus-host disease; therefore, we could not measure the clinical response to HC treatment. One microbiological non-responder had a stable BKV viral load with clinical improvement. Only three patients showed transient grade 2 serum creatinine toxicities, which resolved after completion of concomitant calcineurin inhibitor treatment. CONCLUSIONS: Weekly intravenous low-dose cidofovir without probenecid appears to be a safe and effective treatment option for patients with BKV-associated HC.
Administration, Intravenous ; Adult ; Antiviral Agents/*administration & dosage/adverse effects ; BK Virus/*drug effects/immunology ; Cystitis/diagnosis/*drug therapy/immunology/virology ; Cytosine/administration & dosage/adverse effects/*analogs & derivatives ; Drug Administration Schedule ; Female ; Hematopoietic Stem Cell Transplantation/*adverse effects ; Humans ; Immunocompromised Host ; Male ; Organophosphonates/*administration & dosage/adverse effects ; Polyomavirus Infections/diagnosis/*drug therapy/immunology/virology ; Retrospective Studies ; Time Factors ; Transplantation, Homologous ; Treatment Outcome ; Tumor Virus Infections/diagnosis/*drug therapy/immunology/virology ; Viral Load