BK Virus Infection In Renal Transplant Recipients: Diagnosis And Risk Factors Analysis

Objective To investigate diagnostic methods, epidemiologic feature and risk factors of BK virus infection in renal transplantation recipients and to study its effect on renal graft function.Methods 92 cases of renal transplant recipients in Zhongshan Hospiatal were enrolled in the study of BK virus detection including decoy cells in urinary sediment, BKV-DNA in urine and plasma in comparison with the control group. Patients were followed up and epidemiological features and risk factors of BK virus infection were analyzed.Results Among 92 patients, decoy cells were found in 29(31.5%) patients. The median time to the first positive of decoy cells was 18.3 months post kidney transplantation (KTx). The sensitivity and specificity of decoy cells to diagnose BK virus infection were 67.7% and 86.9% respectively. 22 (23.9%) patients were diagnosed as BK viruria at a median time of 16.3 months post KTx, and 9 (9.8% ) recipients were diagnosed as BK viremia at a median time of 39.5 months post KTx. Positive of decoy cells were closely related to renal graft dysfunction. 8 of 9 renal recipients diagnosed as BK viremia were demonstrated as graft dysfunction. Risk factors of BK virus infection were analyzed by Logistic regression methods, and it was found that immune induction therapy and patients without hemodialysis before KTx were two high risk factors. Whereas, immunosuppressive regimen, primary kidney disease and post-surgery infection were found no significant relationship with BK virus infection.Conclusion BK virus infection is a common complication of Chinese renal transplant recipients.The infection of BK virus may result in graft dysfunction, ureter stenosis and hydronephrosis. Detection of decoy cells and BKV-DNA in urine samples may lead to early diagnosis of BK virus infection.