Chien Jung-Yien, Lin Ching-Kai, Yu Chong-Jen, Hsueh Po-Ren
Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
Front Microbiol. 2020 Sep 22;11:588963. doi: 10.3389/fmicb.2020.588963. eCollection 2020.
This study evaluated the performance of the Xpert MTB/RIF Ultra assay (Xpert Ultra) to detect smear-negative pulmonary tuberculosis (PTB). Xpert Ultra assay was prospectively performed using bronchial washing fluid (BWF) in comparison to COBAS TaqMan MTB (COBAS) assay and mycobacterial culture. Of the 165 enrolled participants, 27 (16.4%) had PTB based on composite reference standard and 16 (9.7%) had culture-confirmed PTB. By the composite reference standard of PTB, the sensitivity of Xpert Ultra (63.0, 95% confidence interval, CI, 42.4-80.6%) was higher than the COBAS assay (25.9%, = 0.006), BWF-culture (33.3%, = 0.029) and sputum-culture (37.0%, = 0.057). Meanwhile, the specificity of Xpert Ultra was 99.3% which was slightly lower than the 100.0% specificity of the COBAS assay ( = 1.000) and cultures ( = 1.000). Against the reference standard of culture-confirmed PTB, Xpert Ultra also had a higher sensitivity (62.5, 95% CI, 35.4-84.8%) than the COBAS assay (31.3%, = 0.077) and was similar to BWF-culture (56.3%, = 0.719) and sputum-culture (62.5%, = 1.000). However, one subject with previously treated old PTB had a false-positive result on the Xpert Ultra assay. This prospective study showed Xpert Ultra assay using BWF had better sensitivity than COBAS assay and mycobacterial cultures but could represent a false positive in patients with inactive old PTB.
本研究评估了Xpert MTB/RIF Ultra检测法（Xpert Ultra）检测涂片阴性肺结核（PTB）的性能。与COBAS TaqMan MTB（COBAS）检测法和分枝杆菌培养相比，前瞻性地使用支气管灌洗液（BWF）进行Xpert Ultra检测法。在165名登记参与者中，根据综合参考标准，27名（16.4%）患有PTB，16名（9.7%）患有培养确诊的PTB。按照PTB的综合参考标准，Xpert Ultra的敏感性（63.0，95%置信区间，CI，42.4 - 80.6%）高于COBAS检测法（25.9%，P = 0.006）、BWF培养（33.3%，P = 0.029）和痰培养（37.0%，P = 0.057）。同时，Xpert Ultra的特异性为99.3%，略低于COBAS检测法（100.0%，P = 1.000）和培养法（100.0%，P = 1.000）。相对于培养确诊PTB的参考标准，Xpert Ultra的敏感性（62.5，95%CI，35.4 - 84.8%）也高于COBAS检测法（31.3%，P = 0.077），与BWF培养（56.3%，P = 0.719）和痰培养（62.5%，P = 1.000）相似。然而，一名既往接受过治疗的陈旧性PTB患者在Xpert Ultra检测法上出现假阳性结果。这项前瞻性研究表明，使用BWF的Xpert Ultra检测法比COBAS检测法和分枝杆菌培养具有更好的敏感性，但在陈旧性非活动性PTB患者中可能出现假阳性。
