Clinical Virology, Laboratory Medicine, University Hospital Basel, Basel, Switzerland.
Transplantation & Clinical Virology, Department of Biomedicine, University of Basel, Basel, Switzerland.
J Med Virol. 2021 Jun;93(6):3804-3812. doi: 10.1002/jmv.26649. Epub 2020 Nov 10.
Many clinical laboratories have replaced virus isolation in cell-culture (VIC) for cytomegalovirus (CMV) by quantitative-nucleic-acid testing (QNAT), rendering clinically relevant CMV-replication difficult to distinguish from CMV-shedding or latent infection. We compared direct VIC in 1109 consecutive bronchoalveolar lavage fluids (BALFs) and a well-validated CMV-QNAT (Basel-CMV-UL111a-77bp). In the retrospective Group 1 (N = 694) and Group 2 (N = 303), CMV-QNAT was performed within 48 h from 2-fold and 10-fold concentrated total nucleic acid (TNA) eluates, respectively. In Group 3 (N = 112), 2-fold and 10-fold concentrated TNA eluates were prospectively analyzed in parallel to VIC. CMV was detected by VIC in 79 of 694 (11%) and 26 of 303 (9%) of Groups 1 and 2, but in 114 of 694 (16%) and 57 of 303 (17%) by CMV-QNAT, respectively. Median CMV loads were significantly higher in VIC-positive than in VIC-negative BALF. The likelihood for CMV detection by VIC was 85% for BALF CMV- loads >4 log copies/ml. In the prospective Group 3, CMV was detected by VIC in 10 of 112 (9%), and in 14 of 112 (13%) and 20 of 112 (18%) by CMV-QNAT, when using 2-fold and 10-fold concentrated TNA eluates, respectively. Notably, CMV was undetectable by CMV-QNAT in 10 VIC-positive cases of Groups 1 and 2, but in none of Group 3. We conclude that CMV-QNAT can be adopted to BALF diagnostics but requires several careful steps in validation. CMV-QNAT loads >10 000 copies/ml in BALF may indicate significant CMV replication as defined by VIC, if short shipment and processing procedures can be guaranteed. Discordance of detecting CMV in time-matched plasma samples emphasises the role of local pulmonary CMV replication, for which histopathology remains the gold standard of proven CMV pneumonia.
许多临床实验室已通过定量核酸检测（QNAT）取代了细胞培养中的病毒分离（VIC）来检测巨细胞病毒（CMV），这使得临床相关的 CMV 复制难以与 CMV 脱落或潜伏感染区分开来。我们比较了 1109 例连续支气管肺泡灌洗液（BALF）的直接 VIC 和经过良好验证的 CMV-QNAT（巴塞尔-CMV-UL111a-77bp）。在回顾性第 1 组（N=694）和第 2 组（N=303）中，CMV-QNAT 分别在 2 倍和 10 倍浓缩总核酸（TNA）洗脱液后 48 小时内进行。在第 3 组（N=112）中，2 倍和 10 倍浓缩的 TNA 洗脱液被前瞻性地与 VIC 同时分析。VIC 在第 1 组和第 2 组中分别检测到 694 例中的 79 例（11%）和 303 例中的 26 例（9%）为 CMV 阳性，但在第 3 组中，694 例中有 114 例（16%）和 303 例中有 57 例（17%）通过 CMV-QNAT 检测到 CMV。VIC 阳性 BALF 的 CMV 负荷中位数明显高于 VIC 阴性 BALF。当 BALF CMV 负荷>4 log 拷贝/ml 时，VIC 检测 CMV 的可能性为 85%。在前瞻性第 3 组中，VIC 在 112 例中有 10 例（9%），在 112 例中有 14 例（13%）和 20 例（18%）通过 CMV-QNAT 检测到 CMV，分别使用 2 倍和 10 倍浓缩的 TNA 洗脱液。值得注意的是，在第 1 组和第 2 组的 10 例 VIC 阳性病例中，CMV-QNAT 未能检测到 CMV，但第 3 组没有。我们得出的结论是，CMV-QNAT 可用于 BALF 诊断，但需要在验证过程中采取几个仔细的步骤。如果可以保证短的运输和处理程序，那么 BALF 中 CMV-QNAT 负荷>10,000 拷贝/ml 可能表明存在由 VIC 定义的显著 CMV 复制。时间匹配的血浆样本中 CMV 检测的不一致性强调了局部肺 CMV 复制的作用，而组织病理学仍然是 CMV 肺炎的金标准。
