Department of Pediatrics, Advanced Pediatrics Centre (APC), Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
J Infect Chemother. 2020 Aug;26(8):823-830. doi: 10.1016/j.jiac.2020.03.019. Epub 2020 May 12.
Loop-mediated isothermal amplification (LAMP) assay is a novel molecular diagnostic technique that can be used for the diagnosis of tuberculosis (TB). It is most suited for developing countries as it is rapid, inexpensive, highly sensitive, requiring minimal infrastructure, training and manpower. Studies in pediatric TB are lacking. We evaluated LAMP in the diagnosis of pediatric pulmonary TB.
This was a cross-sectional analytical study conducted at a tertiary care teaching hospital in North India from July 2014 to June 2015 involving 60 children with suspected pulmonary TB. Respiratory specimens (sputum, gastric lavage, bronchoalveolar lavage and/or endotracheal aspirates) were collected and subjected to BACTEC MGIT 960 culture, IS6110 PCR, and LAMP assay targeting IS6110 gene of Mycobacterium tuberculosis.
Thirty seven children had confirmed and probable TB according to the composite reference standard (CRS). Among all the 3 tests used for diagnosis of Pulmonary TB, LAMP had highest sensitivity (37.8%) followed by PCR (27%), and culture (21.6%) when compared against the predefined CRS. Culture had maximum specificity of 100%; and PCR, and LAMP had specificity of 95-96%. The sensitivity, specificity, PPV, and NPV of LAMP against culture as reference standard were 75%, 72.4%, 42.9%, and 91.3% respectively. Similarly sensitivity, specificity, PPV, and NPV of PCR against culture as reference standard were 75%, 86.2%, 60%, and 86.2% respectively. On combining LAMP with culture, sensitivity increased to 45.7% (7.8% increase, p = 0.04).
We noted that LAMP had highest sensitivity when compared to culture and PCR and comparable specificity.
环介导等温扩增（LAMP）检测是一种新型分子诊断技术，可用于结核病（TB）的诊断。它最适合发展中国家使用，因为它快速、廉价、高度敏感，所需基础设施、培训和人力最少。儿科结核病的研究较少。我们评估了 LAMP 在儿科肺结核诊断中的应用。
这是一项在印度北部的一家三级护理教学医院进行的横断面分析研究，涉及 2014 年 7 月至 2015 年 6 月期间 60 名疑似肺结核的儿童。收集呼吸道标本（痰、胃灌洗、支气管肺泡灌洗和/或气管内抽吸物），并进行 BACTEC MGIT 960 培养、IS6110 PCR 和针对结核分枝杆菌 IS6110 基因的 LAMP 检测。
根据综合参考标准（CRS），37 名儿童被确诊为确诊和可能的结核病。在用于诊断肺结核的 3 种检测方法中，LAMP 的敏感性最高（37.8%），其次是 PCR（27%），而培养的敏感性最低（21.6%）。与预先定义的 CRS 相比，培养的特异性最高（100%），PCR 和 LAMP 的特异性为 95-96%。LAMP 作为参考标准与培养相比的敏感性、特异性、PPV 和 NPV 分别为 75%、72.4%、42.9%和 91.3%。同样，PCR 作为参考标准与培养相比的敏感性、特异性、PPV 和 NPV 分别为 75%、86.2%、60%和 86.2%。当将 LAMP 与培养相结合时，敏感性增加到 45.7%（增加 7.8%，p=0.04）。
我们发现，与培养和 PCR 相比，LAMP 的敏感性最高，特异性相当。
