BACKGROUND: Polyoma BK virus nephropathy (BKVN) is one of the important causes of graft failure and loss among renal transplant patients. Reduction of immunosuppression is the most important preferred treatment approach; however, there is no agreed protocol for additional treatments. OBJECTIVE: Our aim was to investigate the effects on graft survival of intensive treatment protocols for BKVN among renal transplant patients. METHODS: 214 patients were included in the study. All patients underwent investigation for the presence of BKV in plasma samples every 3 months starting from the third month after transplantation. Biopsies were obtained upon detection of graft dysfunction or viremia. If BKVN was positive, viremia was investigated monthly. RESULTS: Plasma plus biopsy-proven BKVN were detected in 19 patients (8.9%), whose mean age was 45.8 ± 12.0 years; 68.4% (n = 13) were male and 94.7% (n = 18) were recipients of a living-donor kidney. There were 5.2% (n = 1) diabetic subjects, and the mean time prior to dialysis was 39.6 ± 44.8 (3-125) months. BKVN was observed at a mean of 6.8 ± 2.9 (4-14) months after the transplantation. It positively correlated with the baseline serum creatinine level (r = 0.159; P = .02), application and cumulative dose of antithymocyte globulin (r = 0.177; r = 0.165; respectively; P = .01), mean tacrolimus dose (r = 0.303; P < .001), and hepatitis B virus positivity (r = 0.169; P = .01). Immunosuppression was decreased in all patients who developed BKVN. In addition, leflunomide was applied in 68%, intravenous immunoglobulin in 74%, and cidofovir in 32% of patients. Acute rejection rates did not increase significantly after lowering immunosuppression (P > .05). CONCLUSION: BKVN is one of the important problems in renal transplant patients. Intensive treatment of BKVN with heterogeneous regimens, including combined treatment with leflunamide + IVIG together with immunosuppressive dose reduction, was an effective approach to prolong graft survival.
BACKGROUND:Polyoma BK virus nephropathy (BKVN) is one of the important causes of graft failure and loss among renal transplant patients. Reduction of immunosuppression is the most important preferred treatment approach; however, there is no agreed protocol for additional treatments. OBJECTIVE: Our aim was to investigate the effects on graft survival of intensive treatment protocols for BKVN among renal transplant patients. METHODS: 214 patients were included in the study. All patients underwent investigation for the presence of BKV in plasma samples every 3 months starting from the third month after transplantation. Biopsies were obtained upon detection of graft dysfunction or viremia. If BKVN was positive, viremia was investigated monthly. RESULTS: Plasma plus biopsy-proven BKVN were detected in 19 patients (8.9%), whose mean age was 45.8 ± 12.0 years; 68.4% (n = 13) were male and 94.7% (n = 18) were recipients of a living-donor kidney. There were 5.2% (n = 1) diabetic subjects, and the mean time prior to dialysis was 39.6 ± 44.8 (3-125) months. BKVN was observed at a mean of 6.8 ± 2.9 (4-14) months after the transplantation. It positively correlated with the baseline serum creatinine level (r = 0.159; P = .02), application and cumulative dose of antithymocyte globulin (r = 0.177; r = 0.165; respectively; P = .01), mean tacrolimus dose (r = 0.303; P < .001), and hepatitis B virus positivity (r = 0.169; P = .01). Immunosuppression was decreased in all patients who developed BKVN. In addition, leflunomide was applied in 68%, intravenous immunoglobulin in 74%, and cidofovir in 32% of patients. Acute rejection rates did not increase significantly after lowering immunosuppression (P > .05). CONCLUSION: BKVN is one of the important problems in renal transplant patients. Intensive treatment of BKVN with heterogeneous regimens, including combined treatment with leflunamide + IVIG together with immunosuppressive dose reduction, was an effective approach to prolong graft survival.