Bajgai Johny, Cho Chi-Hyun, Lee Jong-Han
Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea.
Department of Convergence Medicine, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea.
Diagnostics (Basel). 2025 Jul 14;15(14):1776. doi: 10.3390/diagnostics15141776.
Accurate differentiation between (MTB) and nontuberculous mycobacteria (NTM) is essential for proper diagnosis and treatment. This study compares the diagnostic performance of two commercial real-time PCR kits, AdvanSure TB/NTM and Kogene PowerChek MTB/NTM, for detecting MTB, NTM, and negative (no growth, NG) clinical specimens. A total of 390 clinical residual specimens were collected from patients between December 2022 and June 2023. The samples, including sputum, bronchoalveolar lavage, tracheal aspirate and body fluid, were initially tested with MGIT culture and then analyzed using both PCR kits. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were evaluated. Discrepant results between the two PCR assays were further investigated using sequencing to identify the detected mycobacterial species, and final diagnoses were verified by culture results and review of electronic medical records. Of the 390 specimens, both AdvanSure and PowerChek real-time PCR assays demonstrated 100% sensitivity for both MTB and NTM detection. For MTB detection, AdvanSure demonstrated a specificity of 100%, with a PPV, NPV, and overall accuracy all reaching 100%. In comparison, PowerChek showed a specificity of 98.62%, a PPV of 96.15%, an NPV of 100%, and an overall accuracy of 98.97%. For NTM detection, both AdvanSure and PowerChek exhibited identical performance metrics. The specificity was 99.58% for both assays, with a PPV of 99.34%, NPV of 100%, and an overall accuracy of 99.74%. Five discrepant results were finally confirmed as four NTM detection cases and one negative case by culture and clinical diagnosis which showed four cases of PowerChek MTB+NTM detection and one case of NTM detection, respectively. The PowerChek MTB/NTM real-time PCR kit demonstrated excellent diagnostic performance for the detection of MTB and NTM, with high sensitivity, specificity, and accuracy. Minor discrepancies, particularly in detecting MTB+NTM mixed infections, highlight the importance of complementary sequencing analysis for resolving uncertain results. These findings support the clinical utility of both PCR assays as reliable tools for rapid diagnosis of mycobacterial infections. PowerChek showed occasional false positives, suggesting that optimizing the assay's cutoff threshold or amplification parameters could enhance its specificity and reduce false-positive results in clinically ambiguous cases.
准确区分结核分枝杆菌（MTB）和非结核分枝杆菌（NTM）对于正确的诊断和治疗至关重要。本研究比较了两种商用实时荧光定量PCR试剂盒AdvanSure TB/NTM和Kogene PowerChek MTB/NTM在检测MTB、NTM及阴性（无生长，NG）临床标本方面的诊断性能。2022年12月至2023年6月期间，共收集了390份患者的临床剩余标本。这些样本包括痰液、支气管肺泡灌洗液、气管吸出物和体液，首先用MGIT培养法进行检测，然后使用两种PCR试剂盒进行分析。评估了敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和总体准确性。使用测序进一步研究两种PCR检测之间的差异结果，以鉴定检测到的分枝杆菌种类，并通过培养结果和电子病历审查来验证最终诊断。在390份标本中，AdvanSure和PowerChek实时荧光定量PCR检测对MTB和NTM的检测均显示出100%的敏感性。对于MTB检测，AdvanSure的特异性为100%，PPV、NPV和总体准确性均达到100%。相比之下，PowerChek的特异性为98.62%，PPV为96.15%，NPV为100%，总体准确性为98.97%。对于NTM检测，AdvanSure和PowerChek表现出相同的性能指标。两种检测的特异性均为99.58%，PPV为99.34%，NPV为100%，总体准确性为99.74%。通过培养和临床诊断，最终确认了5个差异结果，分别为4例NTM检测病例和1例阴性病例，其中PowerChek检测分别为4例MTB+NTM阳性和1例NTM阳性。PowerChek MTB/NTM实时荧光定量PCR试剂盒在检测MTB和NTM方面表现出优异的诊断性能，具有高敏感性、特异性和准确性。微小的差异，特别是在检测MTB+NTM混合感染时，凸显了补充测序分析对于解决不确定结果的重要性。这些发现支持了两种PCR检测作为快速诊断分枝杆菌感染的可靠工具的临床实用性。PowerChek偶尔出现假阳性，这表明优化检测的临界值或扩增参数可以提高其特异性，并减少临床诊断不明确情况下的假阳性结果。
