A nonsputum triage test to rule out tuberculosis (TB) disease is a WHO high-priority diagnostic, and a combinatory score based on a 3-gene host signature has shown promise in discriminating TB from other illnesses. We evaluated the accuracy of an early-prototype cartridge assay (“Xpert MTB Host Response” or Xpert-MTB-HR-Prototype) of this 3-gene signature on biobanked blood samples from people living with HIV (PLHIV) against a comprehensive microbiological reference standard (CMRS) and against Xpert MTB/RIF on the first sputum sample alone. We depict results based on performance targets set by the WHO in comparison with a laboratory-based C-reactive protein (CRP) assay. Of 201 patients included, 67 were culture positive for Mycobacterium tuberculosis. The areas under the concentration-time curve (AUCs) for Xpert-MTB-HR-Prototype were 0.89 (confidence interval [CI], 0.83 to 0.94) against the CMRS and 0.94 (CI, 0.89 to 0.98) against Xpert MTB/RIF. Considering Xpert-MTB-HR-Prototype as a triage test (at the nearest upper value of sensitivity to 90%), specificities were 55.8% (CI, 47.2 to 64.1%) compared to the CMRS and 85.9% (CI, 79.3 to 90.7%) compared to Xpert MTB/RIF as confirmatory tests. Considering Xpert-MTB-HR-Prototype as a stand-alone diagnostic test, at a specificity near 95%, the test achieved a sensitivity of 65.7% (CI, 53.7 to 75.9%), while the CRP assay achieved a sensitivity of only 13.6% (CI, 7.3 to 23.4%). In this first accuracy study of a prototype blood-based host marker assay, we show the possible value of the assay for triage and diagnosis in PLHIV.

中文翻译：

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一种新的基于血液的检测方法来鉴定艾滋病毒携带者结核病的诊断准确性研究

一项无痰分流试验可以排除结核病（TB），这是WHO的优先诊断手段，基于3基因宿主特征的综合评分已显示出将结核病与其他疾病区分开的希望。我们针对综合性微生物学参考，评估了来自艾滋病毒感染者（PLHIV）的生物库血样中该3基因签名的早期原型盒测定（“ Xpert MTB宿主反应”或Xpert-MTB-HR-原型）的准确性。标准（CMRS）并仅在第一个痰液样本中针对Xpert MTB / RIF。我们描述了基于由WHO设定的绩效目标与基于实验室的C反应蛋白（CRP）分析相比的结果。在包括的201位患者中，有67位结核分枝杆菌培养阳性。Xpert-MTB-HR-原型在浓度-时间曲线下的面积（AUCs）相对于CMRS为0.89（置信区间[CI]，0.83至0.94），相对于Xpert MTB / RIF为0.94（CI，0.89至0.98）。将Xpert-MTB-HR-Prototype作为分类测试（灵敏度的最接近上限值为90％），与CMRS相比，特异性为55.8％（CI，47.2至64.1％）和85.9％（CI，79.3至90.7） ％）与Xpert MTB / RIF进行比较作为确认性测试。将Xpert-MTB-HR-Prototype作为独立的诊断测试，在接近95％的特异性下，该测试的灵敏度为65.7％（CI为53.7至75.9％），而CRP分析的灵敏度仅为13.6。 ％（CI，7.3至23.4％）。在基于原型血液的宿主标记检测的首次准确性研究中，我们显示了该检测对PLHIV的分类和诊断的可能价值。