BACKGROUND/AIMS: BK virus-associated nephropathy (BKVAN) is an important cause of allograft dysfunction in kidney transplant recipients. It has an unfavorable clinical course, and no definite treatment guidelines have yet been established. Here, we report our center's experience with biopsy-proven BKVAN and investigate factors associated with its progression. METHODS: From January 2004 to April 2013, 25 patients with BKVAN were diagnosed by biopsy at Seoul St. Mary's Hospital. Of the 25 patients, 10 were deceaseddonor transplant recipients and 15 were living-donor transplant recipients. Three of the patients underwent retransplantation. The primary immunosuppressant used was tacrolimus in 17 patients and cyclosporine in eight patients. RESULTS: BKVAN was observed at a mean duration of 22.8 ± 29.1 months after transplantation. The mean serum creatinine level at biopsy was 2.2 ± 0.7 mg/dL. BKVAN occurred with acute rejection in eight patients (28%). Immunosuppression modification was performed in 21 patients (84%). Additionally, leflunomide and intravenous immunoglobulin were administered to 13 patients (52%) and two (8%), respectively. Allograft loss occurred in five patients (27.8%) during the follow- up period at 0.7, 17.1, 21.8, 39.8, and 41.5 months after the BKVAN diagnosis. Advanced stages of BKVAN, increased creatinine levels, and accompanying acute rejection at the time of BKVAN diagnosis increased the risk of allograft failure. CONCLUSIONS: The clinical outcomes in patients with biopsy-proven BKVAN were unfavorable in the present study, especially in patients with advanced-stage BKVAN, poor renal function, and acute allograft rejection.
Adult ; Allografts ; Antiviral Agents/therapeutic use ; BK Virus/*pathogenicity ; Biomarkers/blood ; Biopsy ; Creatinine/blood ; Disease Progression ; Female ; Graft Rejection/diagnosis/drug therapy/immunology/*virology ; Graft Survival ; Humans ; Immunocompromised Host ; Immunosuppressive Agents/adverse effects ; Kaplan-Meier Estimate ; Kidney Transplantation/*adverse effects ; Male ; Middle Aged ; Opportunistic Infections/diagnosis/drug therapy/immunology/*virology ; Polyomavirus Infections/diagnosis/drug therapy/immunology/*virology ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Time Factors ; Treatment Outcome ; Tumor Virus Infections/diagnosis/drug therapy/immunology/*virology

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