Aung Ye Win, Faksri Kiatichai, Sangka Arunnee, Tomanakan Kanchana, Namwat Wises
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Faculty of Associated Medical Science, Khon Kaen University, Khon Kaen 40002, Thailand.
Pathogens. 2023 Feb 18;12(2):345. doi: 10.3390/pathogens12020345.
Tuberculosis (TB) is one of the top 10 causes of death worldwide. It is challenging to find methods of diagnosis of active pulmonary TB that are sensitive enough to detect cases for proper treatment before unintentional transmission. Droplet digital PCR (ddPCR) is a highly sensitive method to detect genetic material of pathogens, but it has rarely been used for diagnosis of TB. This study compared the sensitivity of ddPCR with that of GeneXpert and AFB smear microscopy in 180 leftover sputum samples from patients suspected of having TB on the basis of clinical symptoms and radiography. Absolute quantification of copy numbers of MTB-specific genes was possible using ddPCR targeting the gene. Among the 180 samples, 41.1% were diagnosed as having TB using ddPCR. The sensitivities of AFB smear microscopy, GeneXpert and ddPCR were 41.9%, 82.4% and 100%, respectively. AFB smear microscopy and GeneXpert both had a specificity of 100%, and the specificity of ddPCR was 95.3%. The accuracy of ddPCR (97.2%) is higher than that of GeneXpert (92.7%). This robust ddPCR system could potentially be used as a method for early diagnosis of TB.
结核病（TB）是全球十大死因之一。要找到足够敏感的活动性肺结核诊断方法，以便在无意间传播之前检测出病例并进行适当治疗，这具有挑战性。液滴数字PCR（ddPCR）是一种检测病原体遗传物质的高灵敏度方法，但很少用于结核病的诊断。本研究比较了ddPCR与GeneXpert和抗酸杆菌涂片显微镜检查对180份根据临床症状和影像学怀疑患有结核病患者的剩余痰液样本的敏感性。使用针对该基因的ddPCR可以对结核分枝杆菌特异性基因的拷贝数进行绝对定量。在180份样本中，41.1%的样本通过ddPCR诊断为患有结核病。抗酸杆菌涂片显微镜检查、GeneXpert和ddPCR的敏感性分别为41.9%、82.4%和100%。抗酸杆菌涂片显微镜检查和GeneXpert的特异性均为100%，ddPCR的特异性为95.3%。ddPCR的准确性（97.2%）高于GeneXpert（92.7%）。这种强大的ddPCR系统有可能用作结核病早期诊断的方法。
