BK Viral Infection in Kidney Transplantation: The Role of Induction Therapy.

Abstract

Background: BK viral nephropathy occurs in up to 10% of kidney allograft recipients. The rate of allograft failure, in affected individuals, ranges from 10-50%. To examine the role of induction therapy, in the development of BK viral disease, we performed a retrospective review of our renal transplant database. Methods: All renal transplant recipients over a 36 month period were included. BK viral infection was defined as a plasma BK quantitative PCR > 3,000 copies/ml, and/or a renal allograft biopsy demonstrating BK nephropathy. Statistical analysis was performed on only those allograft recipients with BK studies available. Results: BK infection data was available in 247 patients. The rate of BK infection was 41/247 (16.6%). Baseline immunosuppression, consisting of tacrolimus, mycophenolate sodium, and corticosteroids, was similar for all patients. The incidence of BK infection based on the type of induction agent was: BK infection was more common in patients who received alemtuzumab (13/40, 32.5%) versus basiliximab (2/21, 9.5%), and anti-thymocyte globulin (7/59, 11.9%), or no induction therapy (19/127, 15%; p=0.04). The increased incidence of BK infection observed with alemtuzumab induction was independent of acute cellular rejection or requirement of high-dose corticosteroids, anti-thymocyte globulin, or monoclonal anti-CD3 therapy during the first year post-transplant (OR 3.62, CI 1.35-9.76; p=0.01). Conclusion: In comparison to other induction agents, alemtuzumab is associated with a significantly higher incidence of BK viral infection. Thymoglobulin and basiliximab induction are not associated with a higher incidence of BK viral infection, when compared to patients that do not receive induction therapy.