Outcomes of renal transplant recipients with BK virus infection and BK virus surveillance in the Auckland region from 2006 to 2012

AIM To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy(BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus(BKV) surveillance programme.METHODS A cohort of 226 patients who received their renal transplants from 2006 to 2012 was retrospectively reviewed.RESULTS Seventy-six recipients(33.6%) had a BK viral load(BKVL) test and 9 patients(3.9%) developed BKVN. Cold ischaemia time(HR = 1.18, 95%CI: 1.04-1.35) was found to be a risk factor for BKVN. Four recipients with BKVN had complete resolution of their BKV infection; 1 recipient had BKVL less than 625 copies/mL; 3 recipients had BKVL more than 1000 copies/mL and 1 had graft failure from BKVN. BKVN has a negative impact on graft function [median estimated glomerular filtration rate(eG FR) 22.5(IQR 18.5-53.0) mL /min per 1.73 m^2, P = 0.015), but no statistically significant difference(P = 0.374) in renal allograft function was found among negative BK viraemia group [median e GFR 60.0(IQR 48.5-74.2) mL /min per 1.73 m^2), positive BK viraemia without BKVN group [median eG FR 55.0(IQR 47.0-76.0) mL /min per 1.73 m^2] and unknown BKV status group [median eG FR 54.0(IQR 43.8-71.0) mL /min per 1.73 m^2]. The incidence and treatment outcomes of BKVN were similar to some centres with BKV surveillance programmes.CONCLUSION Recipients with BVKN have poorer graft function. Although active surveillance for BKV has been shown to be effective in reducing incidence of BKVN, it should be tailored specifically to that transplant centre based on its epidemiology and outcomes of BKVN, particularly in centres with limited resources.

Clinical study of different immune induction and BK virus infection after renal transplantation

Objective:To monitor the incidence of BK virus infection in hematuria of renal transplant recipients induced by different immunizations.Methods:A total of 109 patients who underwent renal transplantation in Baogang Hospital of Inner Mongolia from January 2019 to December 2022 were analyzed retrospectively.The results of BK virus DNA detection in urine and blood were observed after operation.They were divided into three groups according to different immunosuppressive induction regimens;35 patients in group A,42 patients in group B,and 32 patients in group C(basiliximab).To explore the effect of different immune induction regimens on BK virus infection in renal transplant recipients.Results:The positive rate of urine BK virus in all patients in 1 month after operation was 10.09%(11/109),which was significantly higher than that of blood BK virus 0%(0/109),and the difference had a statistical significance(p<.05).The positive rate of urine BK virus in all patients in 6 months after operation was 31.19%(34/109),which was significantly higher than that of blood BK virus 3.67%(4/109),and the difference had a statistical significance(p<.05).The positive rate of urine BK virus in all patients in 12 months after operation was 35.79%(39/109),which was significantly higher than that of blood BK virus 5.50%(6/109),and the difference had a statistical significance(p<.05).The urinary BK virus infection rate was increased significantly from 1 month to 6 months after operation,but was not increased significantly from 6 months to 12 months after operation.There was a statistically significant difference between the two groups(p<.05).The BK virus infection rate in renal transplant recipients induced by basiliximab within the first month was significantly lower than that in patients using polyclonal antibodies,but the urinary BK virus infection rate after one year was not significantly different from that in patients using polyclonal antibodies.Conclusions:There are slight differences in BK virus infection after early renal transplantation with different immune induction therapies,but there is no significant difference in the long-term.It is recommended to strengthen the early monitoring of BK virus after renal transplantation,timely adjust immunosuppressive regimens to achieve the early detection and early treatment.