Abstract:
We performed a prospective study to evaluate the diagnostic accuracy of nucleotide matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in identifying nontuberculous mycobacterium (NTM) from clinical respiratory samples. A total of 175 eligible patients were prospectively enrolled, including 108 patients diagnosed with NTM pulmonary disease (NTM-PD) and 67 control patients with other diseases. All specimens were subjected to acid-fast staining, liquid culture combined with MPT64 antigen detection, and a nucleotide MALDI-TOF MS assay. NTM cultures were also subjected to the MeltPro Myco assay for species identification. Altogether, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of nucleotide MALDI-TOF MS were 77.8% (95% CI: 68.6-85.0%), 92.5% (82.8-97.2%), 94.4% (86.8-97.9%), and 72.1% (61.2-81.0%), respectively; these results were not statistically different from the results of culture + MPT64 antigen testing (75.0% [65.6-82.6%], 95.5% [86.6-98.8%], 96.4% [89.2-99.1%], and 70.3% [59.7-79.2%], respectively). In the identification of NTM species, of the 84 nucleotide MALDI-TOF MS positive samples, 77 samples (91.7%) were identified at the species level. Using culture + MeltPro Myco assay as the reference standard, nucleotide MALDI-TOF MS correctly identified 77.8% (63/81) of NTM species. Our results demonstrated that the nucleotide MALDI-TOF MS assay was a rapid single-step method that provided the reliable detection of NTM and identification of NTM species. This new method had the same sensitivity and specificity as the culture + MPT64 antigen method, but was much more rapid.
摘要:
我们进行了一项前瞻性研究,以评估核苷酸基质辅助激光解吸电离飞行时间质谱(MALDI-TOFMS)在从临床呼吸道样本中鉴定非结核分枝杆菌(NTM)的诊断准确性。共有175名符合条件的患者被前瞻性纳入,包括108例诊断为NTM肺病(NTM-PD)的患者和67例其他疾病的对照患者。所有标本均进行抗酸染色,液体培养结合MPT64抗原检测,和核苷酸MALDI-TOFMS测定。还对NTM培养物进行MeltProMyco测定以进行物种鉴定。总之,灵敏度,特异性,阳性预测值(PPV),核苷酸MALDI-TOFMS的阴性预测值(NPV)为77.8%(95%CI:68.6-85.0%),92.5%(82.8-97.2%),94.4%(86.8-97.9%),和72.1%(61.2-81.0%),分别;这些结果与培养+MPT64抗原检测结果无统计学差异(75.0%[65.6-82.6%],95.5%[86.6-98.8%],96.4%[89.2-99.1%],和70.3%[59.7-79.2%],分别)。在NTM物种的鉴定中,84个核苷酸的MALDI-TOFMS阳性样本,在物种水平上鉴定了77个样品(91.7%)。使用培养物+MeltProMyco测定法作为参考标准,核苷酸MALDI-TOFMS正确鉴定了77.8%(63/81)的NTM物种。我们的结果表明,核苷酸MALDI-TOFMS测定是一种快速的单步方法,可提供可靠的NTM检测和NTM物种鉴定。该方法具有与培养+MPT64抗原法相同的灵敏度和特异性,但是要快得多。