The Study Of BK Virus Epidemiology On Renal Allograft In Living Donor Renal Transplant Recipients

BK virus belongs to the polyomavirus, which is an important riskfactor in kidney graft nephropathy. Since the1990s, with the kidneytransplants widely carrying out, the BK virus nephropathy caused by BKVinfection leading to graft loss cases increased significantly. According tothe domestic and foreign studies, about1%to5%of the recipients mayhave BKVN after renal transplantation, half of the BKVN may led to graftloss, which caused the high attention of scholars. Previous studies showedthat the incidence of BK infection and the rate of BKVN after renaltransplantation in309Hospital of PLA single center were consistent withthe foreign research data. This revealed that the BK virus infection wasuniversal in renal transplant recipients.The objective of this study was to investigate the epidemiologicalcharacteristics of BK virus infection in living donor renal transplantrecipients and to analyze the risk factors of BK virus infection andBK virus nephropathy (BKVN).We systematically screened for active BKV infection at preoperativeand at0.5,1,3,6,9,12and15months after transplantation in43livingdonor renal transplant recipients from February1,2012to January31,2013in309Hospital of PLA. The screening tests included regularly testing urineand serum BKV DNA loads, meanwhile recorded the results carefully.Living donors routine screened serum BKV DNA before surgery inPeople’s Liberation Army309Hospital. Routine histopathologicalexamination and immunohistochemist were performed on renal tissuesfrom partial patients who received the tests of renal biopsy． The test results were divided into three groups according to BK viruria,BK viremia and pathological diagnosis BKVN. Then statistical recordedgender, age, postoperative diabetes (PTDM), acute rejection (AR), delayedgraft function (DGF), postoperative pneumonia, preoperative immuneinduction therapy, postoperative immunosuppressive regimen and otherinformation. Then analyzed the risk factors related to living donorrecipients who was infected BK virus and diagnosed BKVN.Throughout the follow-up monitor of average15months (12-18months), we found20cases of urinary BKV DNA-positive recipients, therate was46.5%; and six cases recipients blood BKV DNA were positive,the rate was14.0%; one case of recipient，s biopsy pathology was diagnosedas BKVN, the rate was2.3%. The six month was the viruria and viremiapeak time after transplantation. Application of statistical correlationanalysis showed that gender, BK viremia before renal transplantation,immune induction program, postoperative diabetes, acute rejection andpostoperative pulmonary infection have no correlation with BKV infectionand BKVN (P>0.05); FK506was significantly associated with viremia inliving donor renal transplant recipients who took FK506after the transplantoperation（r=0.319,P=0.037）.Compared with the previous study of this hospital, we can draw theconclusion: BK viremia after living donor kidney transplantation incidencewere lower than cadaver renal transplantation, viruria had the similar rates.After living donor kidney transplantation immune inhibitor was lower, andthe incidence of BKVN was lower. The six month was the viruria andviremia peak time after transplantation, it suggested the importance ofmonitoring urine and blood BKV DNA loads in living donor renalrecipients closely during this period in order to reduce BKVN.Immunosuppressive scheme based on FK506was an independent riskfactor of immune related, which may lead to BKV viruria progress toBKVN in living donor kidney transplant recipients.