Management and Outcome of BK Viremia in Renal Transplant Recipients - A Prospective Single Centre Study.

Abstract

Purpose: BK viremia can lead to BK nephropathy which can progress to graft loss. Our prospective study shows management and outcome of BK viremia in renal transplant recipient. Methods: In this study 34 recipients were diagnosed with BK viremia between 2002 to 2012. They were followed for at least 5 years. Standard immunosuppressive therapy consisted of Steroid, Azathioprine / MMF, Neoral / Tacrolimus was employed. In five patients induction was done with either ATG or IL-2 antagonist. Quantification of BK virus DNA surveillance in plasma / urine was performed at six and twelve months after transplant. Patients with significant viremia (defined as > 10,000 viral copies / ml) underwent graft biopsy and treated with 30-50% reduction in doses of immunosuppression without antiviral therapy. Target CNI level were lowered in the significant viremia group while it was unchanged for all other patients. Results: 2726 renal transplants were carried out between 2002 to 2012. Out of these 34 (8.0%) developed significant BK viremia. Eleven patients (39%) developed BK nephropathy, while 23 (61%) presented with viremia without evidence of BK nephropathy on graft biopsy. Mean plasma level of BK virus DNA declined by 98% at 1 yr after peak viremia. In all 13 patients (26%) developed acute rejection and all of them responded to either Solumedrol or ATG. Conclusion: Reduction in immunosuppression alone resulted in the successful resolution of viremia with preservation of graft function.