Nair Swathy S, Varghese Ria Elza, Saji Anjana, Thekkuveettil Anoopkumar
Division of Molecular Medicine, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, 695012, India.
Sci Rep. 2025 Mar 24;15(1):10069. doi: 10.1038/s41598-025-93565-6.
Current nucleic acid amplification techniques for the diagnosis of pulmonary tuberculosis (TB) lack the simplicity and affordability of achieving the goals envisioned in the WHO END-TB strategy, particularly for low- and middle-income countries (LMICs). Here we report a cost-effective real-time LAMP (rt-LAMP) assay with high sensitivity for the early diagnosis of pulmonary TB. A sample size of 350 was calculated using Buderer's formula. The assay was validated in the laboratory using mpt64 cloned gene targets and clinical patient samples. The lower limit of detection for the rt-LAMP assay was observed as 10 copies/µl. Out of 350 suspected TB patient samples, 47 were positive for MGIT culture (microbiological reference standard, MRS), 42 were positive for Xpert MTB/RIF and 41 were positive for rt-LAMP assay. Compared to MRS, rt-LAMP showed a sensitivity of 89.36% (95% CI 76.9-96.45%) and a specificity of 94.06% (95% CI 90.77-96.44%). When compared to Xpert MTB/RIF, rt-LAMP showed a sensitivity of 93.33% (95% CI 83.80-98.15%), a specificity of 98.62% (95% CI 96.51-99.62%), negative predictive value of 98.62% (95% CI 96.52-99.47%), positive predictive value of 93.33% (95% CI 84.07-97.38%). Youden index value of rt-LAMP was 0.92 when compared with Xpert MTB/RIF, indicating a significantly low false positive rate. As the technology has been developed in an open platform, the assay will be useful in early diagnosis of pulmonary TB, particularly in screening large susceptible populations in LMICs.
目前用于诊断肺结核（TB）的核酸扩增技术缺乏实现世界卫生组织终止结核病战略所设想目标的简便性和可承受性，特别是对于低收入和中等收入国家（LMICs）而言。在此，我们报告一种具有高灵敏度的经济高效的实时环介导等温扩增（rt-LAMP）检测方法，用于肺结核的早期诊断。使用布德勒公式计算得出样本量为350。该检测方法在实验室中使用mpt64克隆基因靶点和临床患者样本进行了验证。rt-LAMP检测方法的检测下限为10拷贝/微升。在350份疑似结核病患者样本中，47份MGIT培养呈阳性（微生物学参考标准，MRS），42份Xpert MTB/RIF检测呈阳性，41份rt-LAMP检测呈阳性。与MRS相比，rt-LAMP的灵敏度为89.36%（95%置信区间76.9-96.45%），特异性为94.06%（95%置信区间90.77-96.44%）。与Xpert MTB/RIF相比，rt-LAMP的灵敏度为93.33%（95%置信区间83.80-98.15%），特异性为98.62%（95%置信区间96.51-99.62%），阴性预测值为98.62%（95%置信区间96.52-99.47%），阳性预测值为93.33%（95%置信区间84.07-97.38%）。与Xpert MTB/RIF相比，rt-LAMP的约登指数值为0.92，表明假阳性率显著较低。由于该技术是在开放平台上开发的，该检测方法将有助于肺结核的早期诊断，特别是在低收入和中等收入国家筛查大量易感人群方面。
