Gowda Nikhil C, Ray Animesh, Soneja Manish, Khanna Arjun, Sinha Sanjeev
Department of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Department of Pulmonary Medicine and Critical Care Medicine, Yashoda Superspeciality Hospital, Kaushambi, Uttar Pradesh, India.
Lung India. 2018 Jul-Aug;35(4):295-300. doi: 10.4103/lungindia.lungindia_412_17.
Sputum smear-negative and sputum-scarce pulmonary tuberculosis (PTB) is a diagnostic challenge. Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) provides a rapid diagnosis on high-quality biological specimen obtained by bronchoscopy.
The aim of this study is to evaluate Xpert MTB/RIF on bronchoalveolar lavage (BAL) fluid in sputum smear-negative and sputum-scarce PTB patients.
Tertiary care hospital in India.
This was prospective observational study.
Between January 2015 and November 2016, we prospectively recruited sputum-smear negative and sputum-scarce patients under evaluation for PTB and performed BAL. Sensitivity, specificity, positive, and negative predictive values were calculated for the diagnosis of PTB on BAL fluid for acid-fast bacilli smear and Xpert MTB/RIF using liquid culture as the reference standard and compared to the final diagnosis based on composite reference standard. Sensitivity, specificity, and predictive values were calculated with 95% class intervals. McNemar's test was used for comparison of sensitivities.
Of the 60 patients included, 52 (88.3%) had a final diagnosis of PTB and 16 (26.7%) were culture confirmed. Xpert MTB/RIF had a sensitivity and specificity of 81% (54%-96%) and 73% (56%-85%) in culture confirmed cases; 46% (32%-60%) and 100% (63%-100%) for the final diagnosis; 32% (17%-51%) and 100% (54%-100%) in culture negative cases, respectively. Culture had a sensitivity of 32% (20%-47%) for the final diagnosis.
In sputum smear-negative and sputum-scarce patients with clinico-radiological features of PTB Xpert MTB/RIF has good sensitivity for diagnosis on BAL fluid. It is useful even when cultures are negative.
痰涂片阴性及痰量少的肺结核（PTB）是一项诊断挑战。Xpert 结核分枝杆菌/利福平（MTB/RIF）检测可对通过支气管镜获取的高质量生物标本进行快速诊断。
本研究旨在评估 Xpert MTB/RIF 检测在痰涂片阴性及痰量少的 PTB 患者支气管肺泡灌洗（BAL）液中的应用。
印度的一家三级护理医院。
这是一项前瞻性观察性研究。
2015 年 1 月至 2016 年 11 月期间，我们前瞻性招募了正在接受 PTB 评估的痰涂片阴性及痰量少的患者，并进行了 BAL 检查。以液体培养作为参考标准，计算了 BAL 液中抗酸杆菌涂片和 Xpert MTB/RIF 检测对 PTB 诊断的敏感性、特异性、阳性预测值和阴性预测值，并与基于综合参考标准的最终诊断结果进行比较。敏感性、特异性和预测值以 95%的置信区间计算。采用 McNemar 检验比较敏感性。
纳入的 60 例患者中，52 例（88.3%）最终诊断为 PTB，16 例（26.7%）经培养确诊。在培养确诊的病例中，Xpert MTB/RIF 的敏感性和特异性分别为 81%（54% - 96%）和 73%（56% - 85%）；对于最终诊断，敏感性和特异性分别为 46%（32% - 60%）和 100%（63% - 100%）；在培养阴性的病例中，敏感性和特异性分别为 32%（17% - 51%）和 100%（54% - 100%）。培养对于最终诊断的敏感性为 32%（20% - 47%）。
对于具有 PTB 临床放射学特征的痰涂片阴性及痰量少的患者，Xpert MTB/RIF 检测在 BAL 液诊断中具有良好的敏感性。即使培养结果为阴性，该检测仍有用。
