Department of Laboratory Medicine, Clinical Laboratories, University of California San Francisco, San Francisco, CA 94107, United States.
J Clin Virol. 2012 Dec;55(4):310-6. doi: 10.1016/j.jcv.2012.08.016. Epub 2012 Sep 11.
Polyomavirus-associated nephropathy is a significant cause of kidney rejection in renal transplant recipients. Quantification of BK viral load in plasma and urine can predict the development of polyomavirus-associated nephropathy, though each assay requires careful evaluation of analytical and clinical performance characteristics for optimal use.
This study evaluated the analytical and clinical performance characteristics of the Simplexa BK virus quantitative PCR assay.
Analytical validation was performed using commercial standards, BK virus stock culture, and patient specimens. Clinical performance was evaluated using biopsy-proven BK nephropathy as the gold standard.
The Simplexa BK virus quantitative PCR assay was linear over a range of 2.7-10.4 log(10) copies/mL. Limit of detection was 2.7-2.8 log(10) copies/mL in plasma and urine samples. Sensitivities were 100% and 100% and specificities were 84% and 86% for plasma and urine samples, respectively, when compared to a reference BK assay. Clinical cutoff values of 4.0 log(10) copies/mL (plasma) and 7.5 log(10) copies/mL (urine) yielded 100% sensitivity and specificities of 87.5% and 85%, respectively, for biopsy-proven polyomavirus nephropathy.
The Simplexa BK virus quantitative PCR assay has high sensitivity and acceptable analytical characteristics for clinical use. The clinical cutoff values presented here provide a rational approach to the monitoring and treatment of renal transplant recipients for polyomavirus-associated nephropathy.
多瘤病毒相关性肾病是肾移植受者发生肾排斥的重要原因。通过检测血浆和尿液中的 BK 病毒载量，可以预测多瘤病毒相关性肾病的发生，但是每种检测方法都需要仔细评估分析和临床性能特征，以实现最佳应用。
本研究评估 Simplexa BK 病毒定量 PCR 检测方法的分析和临床性能特征。
使用商业标准品、BK 病毒储备液和患者标本进行分析验证。以活检证实的 BK 肾病为金标准评估临床性能。
Simplexa BK 病毒定量 PCR 检测方法在 2.7-10.4 log(10)拷贝/mL 范围内呈线性。在血浆和尿液样本中，检测限为 2.7-2.8 log(10)拷贝/mL。与参考 BK 检测方法相比，该方法在血浆和尿液样本中的灵敏度均为 100%，特异性分别为 84%和 86%。当临床界值分别为 4.0 log(10)拷贝/mL（血浆）和 7.5 log(10)拷贝/mL（尿液）时，对活检证实的多瘤病毒肾病的灵敏度和特异性分别为 100%和 87.5%和 85%。
Simplexa BK 病毒定量 PCR 检测方法具有较高的灵敏度和可接受的分析性能，适用于临床应用。本文提出的临床界值为监测和治疗肾移植受者多瘤病毒相关性肾病提供了合理的方法。
