BACKGROUND: The BK nephropathy (BKN) shows a 10% prevalence among cases of kidney transplantation (KT). We assessed the incidence of BK replication in KT recipients as well as our updated screening strategy and the impact of interventions on BK virus infections. METHODS: Since September 2007, our screening protocol for BK virus included examination of urine cytology or BK virus DNA real-time polymerase chain reaction (PCR) detection on postoperative days 1, 5, 9, 16, 24, 36, 48 weeks up to 1 year. IR present, we tested urine BK virus DNA PCR quantitation. We applied the updated screening protocol from August 2010. It urine BK DNA PCR quantification was above 10(7) copies/mL, we checked regularly blood the BK virus DNA PCR quantification. In addition, if the blood BK virus DNA load was above 10(4) copies/mL and the serum creatinine elevated, we was performed an allograft biopsy. Between September 2007 and December 2011, the 58 recipients who showed BK viremia were enrolled in the present study in 2 groups according to the period of screening protocol (era I, era II). RESULTS: The time between kidney transplantation and BK viremia detection of era II was shorter than that of era I (16 vs 29 weeks; P = .001). Viremia clearance rate at 6 months in era II was significant higher than that of era I (82% vs 36.8%; P = .001) as well as at 12 months (100% vs 61.1%, P < .001) after intervention. Interestingly, viremia clearance at 12 months after intervention was 100% in era II. CONCLUSION: An updated screening protocol for BK virus allowed early detection and accurate diagnosis of BKN. Early detection of BK virus infection enabled early intervention and improved viral clearance rate.
BACKGROUND: The BK nephropathy (BKN) shows a 10% prevalence among cases of kidney transplantation (KT). We assessed the incidence of BK replication in KT recipients as well as our updated screening strategy and the impact of interventions on BK virus infections. METHODS: Since September 2007, our screening protocol for BK virus included examination of urine cytology or BK virus DNA real-time polymerase chain reaction (PCR) detection on postoperative days 1, 5, 9, 16, 24, 36, 48 weeks up to 1 year. IR present, we tested urine BK virus DNA PCR quantitation. We applied the updated screening protocol from August 2010. It urine BK DNA PCR quantification was above 10(7) copies/mL, we checked regularly blood the BK virus DNA PCR quantification. In addition, if the blood BK virus DNA load was above 10(4) copies/mL and the serum creatinine elevated, we was performed an allograft biopsy. Between September 2007 and December 2011, the 58 recipients who showed BK viremia were enrolled in the present study in 2 groups according to the period of screening protocol (era I, era II). RESULTS: The time between kidney transplantation and BK viremia detection of era II was shorter than that of era I (16 vs 29 weeks; P = .001). Viremia clearance rate at 6 months in era II was significant higher than that of era I (82% vs 36.8%; P = .001) as well as at 12 months (100% vs 61.1%, P < .001) after intervention. Interestingly, viremia clearance at 12 months after intervention was 100% in era II. CONCLUSION: An updated screening protocol for BK virus allowed early detection and accurate diagnosis of BKN. Early detection of BK virus infection enabled early intervention and improved viral clearance rate.