Sung Heungsup, Choi Byung Hoo, Pyo Yeon Jung, Kim Mi-Na, Han Duck Jong
Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea.
J Korean Med Sci. 2008 Oct;23(5):814-8. doi: 10.3346/jkms.2008.23.5.814.
Quantitative measurement of BK virus DNA (Q-BKDNA) has been used for the early diagnosis and monitoring of BK virus-associated nephropathy (BKVAN). This study was designed to determine the BKDNA cutoff for the diagnosis of BKVAN. Between June 2005 and February 2007, 64 renal transplant recipients taken renal biopsies due to renal impairment submitted plasma and urine for Q-BKDNA. Eight BKVAN patients (12.5%) had median viral loads of 6.0 log10 copies/mL in plasma and 7.3 log10 copies/mL in urine. Among 56 non-BKVAN patients, 45 were negative for Q-BKDNA; 4 were positive in plasma with a median viral load of 4.8 log10 copies/ mL, and 10 were positive in urine with a median viral load of 4.8 log10 copies/mL. Receiver operating characteristic curve analysis showed that a cutoff of 4.5 log10 copies/mL in plasma and a cutoff of 5.9 log10 copies/mL in urine had a sensitivity of 100% and a specificity of 96.4%, respectively. A combined cutoffs of 4 log10 copies/ mL in plasma and 6 log10 copies/mL in urine had better performance with a sensitivity of 100% and a specificity of 98.2% than each cutoff of urine or plasma. QBKDNA with the combined cutoffs could reliably diagnose BKVAN in renal transplant recipients.
BK病毒DNA定量检测（Q-BKDNA）已用于BK病毒相关性肾病（BKVAN）的早期诊断和监测。本研究旨在确定诊断BKVAN的BKDNA临界值。2005年6月至2007年2月期间，64例因肾功能损害接受肾活检的肾移植受者提交了血浆和尿液样本进行Q-BKDNA检测。8例BKVAN患者（12.5%）血浆中病毒载量中位数为6.0 log10拷贝/mL，尿液中为7.3 log10拷贝/mL。在56例非BKVAN患者中，45例Q-BKDNA检测为阴性；4例血浆检测为阳性，病毒载量中位数为4.8 log10拷贝/mL，10例尿液检测为阳性，病毒载量中位数为4.8 log10拷贝/mL。受试者工作特征曲线分析显示，血浆临界值为4.5 log10拷贝/mL，尿液临界值为5.9 log10拷贝/mL时，敏感性分别为100%和特异性为96.4%。血浆临界值为4 log10拷贝/mL和尿液临界值为6 log10拷贝/mL的联合临界值表现更佳，敏感性为100%，特异性为98.2%，优于单独的尿液或血浆临界值。具有联合临界值的Q-BKDNA能够可靠地诊断肾移植受者中的BKVAN。
