Retrospective Analysis Of BK Virus Infection Status And Risk Factors In Renal Transplant Recipients

Objective:To retrospectively analyze the incidence and risk factors for BK virus infection and its development after single-center kidney transplantation,and to provide reference for the prevention and early diagnosis of BK virus infection after kidney transplantation.Methods:According to the inclusion and exclusion criteria,clinical information and followup data within 18 months after surgery were collected from 561 kidney transplant recipients(deceased and living donors)who underwent transplantation at the First Hospital of Jilin University from January 2018 to December 2020.The patients were retrospectively analyzed and divided into four groups: the control group(372 recipients with negative BKV monitoring or persistently low viral load),high-level BK virus urinary group(128 recipients with urine BKV DNA load ≥1.0×107copies/m L and negative plasma),BK virus bloodstream group(52 recipients with detected BKV DNA in plasma and any urine viral load),and BK virus nephropathy(BKVN)group(9recipients confirmed by transplant kidney biopsy to have BKVN).The perioperative data and postoperative follow-up data among the four groups were compared and analyzed.The results of continuous variables were expressed as mean ± standard deviation(SD),and categorical variables were expressed as numbers(percentages).ANOVA and chi-square test(Fisher’s exact test)were used for the analysis of continuous variables and categorical variables,respectively.Variables with P<0.1 in the univariate analysis were included in the ordered multivariate logistic regression model to analyze the independent risk factors for postoperative BK virus infection.Results:Within 18 months after surgery,the incidence of high-level BKV urinary group was 33.69%(189/561),with an average detection time of(4.2±3.8)months after surgery;the incidence of BKV bloodstream group was 10.87%(61/561),with an average detection time of(5.2±3.6)months after surgery;the incidence of BKVN was1.78%(10/561),with an average detection time of(7.0±4.0)months after surgery.The univariate analysis showed that recipient gender(P=0.098),recipient age(P=0.082),immunosuppressive regimen(P<0.001),history of acute rejection(P=0.020),and donor type(P=0.084)were related to BKV infection.After including the factors with P<0.1 in the multivariate ordered logistic regression,male recipients(P=0.013),the immunosuppressive maintenance regimen of tacrolimus+ mycophenolate mofetil+prednisone(Tac +MMF+ Pred)combination(P<0.001),and history of acute rejection(P=0.002)were independent risk factors for postoperative BKV infection.Conclusions:(1)The first year after kidney transplantation is the peak period of BK virus infection,and strengthening the monitoring of BK virus during this period is necessary.(2)Male recipients,the immunosuppressive maintenance regimen of Tac +MMF+Pred combination,and history of acute rejection are independent risk factors for the development of postoperative BKV infection.(3)Compared with female recipients,male recipients are more prone to BK virus urinary symptoms,and history of acute rejection is a risk factor for post-transplant BKV bloodstream infection in kidney transplant recipients.