COMPLICATIONS - INFECTIONS

V. Patel, A. Gautam, L. Pelletier, J. Orozco, J. Francis, M. Nuhn
Section Of Transplantation, Department Of Surgery, Boston University School of Medicine, Boston/MA/UNITED STATES OF AMERICA

Body: Background: We started a universal screening of all our kidney transplant recipients for BK virus as a part of the post transplant care in 2005. This is a review of our experience in patients with at least 6 months post transplant follow up. Methods: Retrospective chart evaluation of all kidney transplants performed by our center from January 2005 to August 2009. Urine PCR for BK Virus was done on all patients starting from 4 weeks post transplantation and if negative repeated monthly for first 6 months and every 3 – 4 months subsequently. If the test was positive, on the next visit a urine and blood BK virus PCR was done and repeated every 2-4 weeks as the patient was followed with slow reduction in immunosuppression. The quantitative range of this assay is 2.6-8.6 log copies/mL (390-390,000,000 copies/mL). A kidney biopsy was done if indicated by graft dysfunction. Results: 153 kidney transplants were done during the study period. There were 4 graft losses within the first 6 weeks and these were excluded from analysis. Induction immunosuppression consisted of IL-2 antibody in 105 and thymoglobulin in 44 patients. In 104 patients (70%) the urine BK virus PCR remained negative. In 20 (13%) patients only the urine was positive for BK virus, and an additional 24 (16%) patients had a positive BK virus PCR in blood. There was no statistical difference (p=0.0515) in incidence according to induction [IL-2 75 (72%) never, 15 (14%) urine only, 15(14%) blood; Thymoglobulin 26 (59%) never, 8 (18%) urine and 10 (22%) blood]. Delayed graft function was seen in 44 (30%) patients. There was no difference (p=0.4813) in these subgroups [No DGF 72 (69%) never, 14 (13%) urine only, 19 (18%) blood; DGF 32 (72%) never, 6 (14%) urine only, 6 (14%) blood]. The mean time to first detection was shorter with thymoglobulin induction (146 days; range 26-367 days) as compared to IL-2 (350 days; range 23-1198 days). Urine only positivity was first detected from 37 to 1198 (mean 428 days) and blood 26 to 762 days (mean 167 days). With reduction in immunosuppression there was gradual reduction and elimination of positive PCR tests in all cases except one which resulted in graft failure. In all other cases there was no increase in serum creatinine. The only biopsy was done in the one case with rapid deterioration and showed extensive BK nephropathy. Conclusions: Routine universal BK virus surveillance is cost effective as it tends to detect BK virus replication early and reduction of immunosuppression with continued viral monitoring results in good outcome with renal preservation.

Disclosure: All authors have declared no conflicts of interest.