肾移植患者尿小圆上皮细胞阳性指标与BK病毒尿症的临床相关性

 目的 分析肾移植患者尿液中小圆上皮细胞（small round epithelial cells，SREC）阳性指标与BK病毒尿症的相关性。方法 定期收集2017年1月至2019年10月的152名肾移植患者的尿液标本，检测尿SREC指标以及运用实时荧光定量PCR方法检测尿液标本中BKV-DNA拷贝数，并对检测结果进行分析评价。将BK病毒尿症患者的尿沉淀进行尿沉淀染色液和免疫荧光染色处理。结果 36名（23%）BKV尿症患者发病时间为术后（2.5±0.5）个月，患者尿液标本里发现94%为SREC阳性指标，首次检测SREC阳性指标的中位时间为移植后（1.0±0.5）个月，SREC阳性指标以及SREC持续阳性时间段（the duration of SREC positivity，DSRECP）在BK病毒尿症患者的检测率高于非BK病毒尿症患者（P<0.05）。SREC持续阳性时间段能提前（1.0±0.5）个月预测BK病毒尿症发生，阳性预测值为94.44%，阴性预测值为85.34%。回归模型分析证实SREC阳性指标与阳性持续时间段可预测BK病毒尿症的发生不受干扰因素影响（P<0.05），ROC曲线中SREC阳性持续时间段在诊断BK病毒尿症的曲线下面积（AUC）为89.11%，cut-off值为85天，差异具有统计学意义。结论 肾移植患者尿SREC阳性指标与BK病毒尿症具有显著相关性，可作为临床上早期预测并辅助诊断BK病毒尿症的潜在临床指标。

Positive indicators of urine small round epithelial cells and their clinical correlation with BK viruria in renal transplant recipients

Objective To analyze the correlation between positive indicators of small round epithelial cells (SREC) in urine and BK viruria in renal transplantation recipients. Method A total of 152 renal transplantation patients' urine samples from Jan 2017 to Oct 2019 were collected routinely. The urine small round epithelial cell indicators were detected, and real-time fluorescent quantitative PCR was used to detect the BKV-DNA test during the time of follow-up. Urine sediment specimens from renal transplant recipients with BK viruria were processed with urine sediment staining and immunofluorescence. Results Thirty-six (23%) patients with BK viruria time of onset was (2.5±0.5) months. 94% of patients' urine samples were positive for SREC. The median time for first detection of SREC positive indicators was (1.0±0.5) months after transplantation. The SREC positive indicators and the duration of SREC positivity (DSRECP) in patients with BK viruria was higher than that in non-BK viruria patients (P<0.05). DSRECP could predict the occurrence of BK viruria (1.0±0.5) months in advance, and the positive prediction value was 94.44%, and the negative predictive value was 85.34%. The immunofluorescence results confirmed that there BK viruria particles were in the cytoplasm of SREC, and the number of SREC was directly proportional to copy number of urine BKV-DNA, and the cell morphogenesis was different with Decoy cells. Regression model analysis confirmed that SREC positive indicators and DSRECP could predict the occurrence of BK viruria(P <0.05) without disruption. The area under the ROC curve (AUC) for the diagnosis of BK viruria for DSRECP in the ROC curve was 89.11%, and the cut-off value was 85 days, which was statistically significant. Conclusion Urine SREC in renal transplant recipients can predict the occurrence of BK viruria, and SREC potentially can be a clinical indicator for early clinical prediction and an aid to BK viruria.