肾移植受者BK病毒感染的检测方法及免疫抑制方案对BK病毒活化的影响

目的 探讨肾移植术后受者BK病毒感染的检测方法及免疫抑制方案对BK病毒活化的影响.方法 选择1999年1月至2007年1月问进行肾移植术的200例受者为研究对象,其中100例基础免疫抑制方案为他克莫司(FK506)十霉酚酸酯(MMF)的受者作为密切观察组;另100例基础免疫抑制方案不同、但在年龄和术后是否发生急性排斥反应方面与密切观察组受者相一致(按1:1匹配)的受者作为对照观察组.在肾移植术后平均15.3个月时,分别采集所有受者的血、尿样本,行BK病毒尿沉渣Decoy细胞计数与BK病毒DNA含量的检测.分析和比较尿Decoy细胞计数、尿BK病毒含量及血BK病毒含量之间的关系;比较两组Decoy细胞、BK病毒尿症与BK病毒血症阳性率的差异.结果 200例受者的尿Decoy细胞、BK病毒尿症与病毒血症的阳性率分别为:34.0%、36.0%和16.5%.尿Decoy细胞计数与尿BK病毒含量呈正相关(r=0.714,P＜0.001),但尿液和外周血中BK病毒含量无明显相关性(P＞0.05).密切观察组的尿Decoy细胞、BK病毒尿症与BK病毒血症的阳性率分别为49%、50%和24%,对照观察组上述指标的阳性率分别是19%、22%和9%,两组的差异有统计学意义(P＜0.01).结论 尿沉渣Decoy细胞计数方法简单、易行并敏感,可以做为BK病毒活化的指标;血、尿BK病毒DNA的检测可进一步了解病毒活化情况、筛杳BK病毒相关的移植肾肾病.FK506+MMF的组合免疫抑制方案易发生BK病毒的活化,受者术后需进行密切观察和相关的检测.

Clinical diagnosis of BK virus infection in renal transplant recipients and influence of the immunosuppressive protocol on BKV replication

Objective To investigate the methods for clinical diagnosis of BK virus (BKV) infection and to analyze the influence of immunosuppressive protocol on BKV activation in renal transplant recipients. Methods 200 renal recipients receiving renal transplantation during 1999. 1-2007. 1 were selected as objectives, among which, 100 cases subject to FKS06 + MMF protocol were regarded as the intensive observation group; with different immunosuppressive protocol, but the same age and the occurrence of the acute rejection as those of the intensive observation group, the other 100 recipients served as control observation group. 15.3 months, on the average after kidney transplantation,the urine and peripheral blood (PB) samples of 200 renal transplant recipients were taken for the BKV cytological test of urinary sediment and real-time PCR for BKV DNA of both urine and PB in order to analyze the relationship among the amount of decoy cells in urine, the BKV load in urine and the BKV load in PB and compare the positive rate of urine decoy cell, BKV viruria and viremia between the above two groups. Results The positive rate of urine decoy cell, BKV viruria and viremia in all patients were 34%, 36% and 16%, respectively. The amount of deooy cells in urine samples was related to the BKV load in urine samples (r=0.714, P＜0.001), but the BKV load in urine samples was not related to that in PB samples (P=0.14). The positive rate of urine decoy cell, BKV viruria and viremia in the intensive observation group were 49%, 50% and 24%, and in control observation group 19%, 22% and 9%, respectively, with the difference being significant between two groups.Conclusions Urine cytology is very convenient, useful and sensitive for the evaluation of BKV replication. Also BKV DNA detection in the urine and peripheral blood is important to screen the evidence of BK reaction further in order to prevent irreversible graft damage of BKVAN. Using FK506 + MMF can increase the infection rate of BKV in renal transplant recipients, and intensively BKV monitoring is necessary for these recipients.