环介导等温扩增法对无痰或痰涂阴肺结核的诊断价值

Diagnostic value of loop-mediated isothermal amplification method in non sputum or smear negative pulmonary tuberculosis

目的:探讨环介导等温扩增法(loop-mediated isothermal amplification,LAMP)检测支气管肺泡灌洗液对无痰或涂阴肺结核的诊断价值。方法:采用前瞻性研究方法,纳入2021年4月至2022年4月重庆市巫山县人民医院收治且符合入组标准的无痰/痰涂片阴性疑似肺结核患者作为研究对象,均在支气管镜下刷片行荧光染色显微镜检查(简称“涂片镜检”),并取支气管肺泡灌洗液行LAMP和GeneXpert MTB/RIF(简称“Xpert”)检测结核分枝杆菌复合群DNA。以最终临床诊断为参照标准,分析3种方法在所有疑似肺结核患者中的检测效能。结果:研究共纳入232例患者,以最终临床诊断将患者分为涂阴/无痰肺结核患者(139例)和非结核肺病患者(93例)。LAMP、Xpert和涂片镜检对232例疑似肺结核患者的检测阳性率分别为43.53%(101/232)、43.97%(102/232)和8.19%(19/232)。以最终临床诊断为参照标准,LAMP、Xpert和涂片镜检对无痰/涂阴肺结核的检测敏感度分别为71.94%(100/139)、72.66%(101/139)和13.67%(19/139),特异度分别为98.92%(92/93)、98.92%(92/93)和100.00%(93/93),诊断一致率分别为82.76%(192/232)、83.19%(193/232)和48.28%(112/232),约登指数分别为0.709、0.716和0.137。结论:LAMP对无痰/涂阴肺结核患者支气管肺泡灌洗液的检测效能与Xpert基本一致,可明显提高早期诊断率;且LAMP操作简便、收费价格低廉,更适用于基层医疗机构推广应用。

Objective:To explore the diagnostic value of loop-mediated isothermal amplification(LAMP)in detecting bronchoalveolar lavage fluid(BALF)in non sputum or smear negative pulmonary tuberculosis.Methods:The prospective study method was adopted,with the subjects being the sputum free or smear negative suspected pulmonary tuberculosis patients who were admitted to Wushan County People’s Hospital of Chongqing from April 2021 to April 2022 and met the inclusion criteria;they all brushed under bronchoscope for fluorescent staining microscopy(referred to as“smear”),and took BALF for LAMP and GeneXpert MTB/RIF(referred to as“Xpert”)to detect Mycobacterium tuberculosis complex DNA.With the final clinical diagnosis as the reference standard,the detection efficiency of the three methods was analyzed.Results:A total of 232 patients were included in the study.The patients were divided into smear negative/sputum free pulmonary tuberculosis patients(139 cases)and non tuberculosis pulmonary disease patients(93 cases)according to the final clinical diagnosis.The positive rates of LAMP,Xpert and smear in 232 patients with suspected pulmonary tuberculosis were 43.53%(101/232),43.97%(102/232)and 8.19%(19/232),respectively.Taking the final clinical diagnosis as the reference standard,the detection sensitivity of LAMP,Xpert and smear for sputum free or smear negative pulmonary tuberculosis were 71.94%(100/139),72.66%(101/139)and 13.67%(19/139)respectively;the specificity were 98.92%(92/93),98.92%(92/93)and 100.00%(93/93)respectively;the diagnostic coincidence rates were 82.76%(192/232),83.19%(193/232)and 48.28%(112/232);the Yoden index were 0.709,0.716 and 0.137,respectively.Conclusion:The detection efficiency of LAMP for BALF in patients with sputum free or smear negative pulmonary tuberculosis is basically consistent with that of Xpert,significantly improving the early diagnosis rate;in addition,LAMP is easy to operate and cheap,which is more suitable for the promotion and application of grass-roots medical institutions.