BK Virus Nephropathy in Renal Transplantation and the Effect of Intravenous Immunoglobulin: A Prospective Longitudinal Single-Center Study in South Asia.

Aims and Objectives: The aim was to assess the prevalence and treatment of BK virus nephropathy (BKVN) in patients who underwent renal transplantation at a single center in South India with a 1-year follow-up analysis. To assess the efficacy of treatment with intravenous immunoglobulin (IvIg) in cases of proven BKVN. Materials and Methods: Three hundred and seventy-one patients underwent renal transplantation from 2018 to 2020. All were screened for BKVN with quantitative serum polymerase chain reaction (PCR) every 3 months for 1 year after transplant. Patients with positive tests underwent renal allograft biopsy. In all patients, antimetabolite was stopped, tacrolimus dose was reduced, and leflunomide was started. All patients with biopsy-proven BKVN were administered IvIg 2 grams/kg over 5 days and had a 1-year follow-up. Results: Fourteen patients had BK viremia; 12 had biopsy-proven BKVN. All were male with a mean age of mean age: 45.3 years ± 14.8 standard deviation (SD). Induction: basiliximab (7) and antithymocyte globulin (ATG) (7). Maintenance immunosuppression: tacrolimus, enteric-coated mycophenolate mofetil, and prednisolone. The median presentation time was 12 months. Mean graft function: baseline S. Creatinine of 1.32 mg/dL changed to 2.01 mg/dL at diagnosis. The mean presenting BKV PCR (copies/ml) was 44912 ± 56285 SD. No significant differences were observed in time of presentation, severity, mean tacrolimus level, and graft failure between patients receiving basiliximab or ATG. There were two relapses; two grafts failed. Class I BKVN had a better prognosis. Graft survival at 1 year was 85.71%. Conclusions: This is the first South Asian follow-up study of BKVN in kidney transplant recipients treated with IvIg. BKVN was documented in the first 15 months after transplant. There was no increased prevalence of BKVN in patients with ATG. Histopathological class has prognostic relevance with Class I having a better prognosis. Multipronged treatment, including IvIg, leads to 1-year graft survival of 85.71%. Long-term outcomes need follow-up. [ABSTRACT FROM AUTHOR]