Clinical application of time-of-flight mass spectrometry nucleic acid detection technology in diagnosis of drug-resistant pulmonary tuberculosis

Purpose: This study aims to evaluate the clinical diagnostic value of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for tuberculosis and drug-resistant tuberculosis.

Patients and methods: Totally 201 pulmonary tuberculosis patients were recruited retrospectively. All patients underwent smear microscopy, Mycobacterium growth indicator tube (MGIT) 960 culture, loop-mediated isothermal amplification (LAMP) molecular testing, Xpert MTB/RIF (Xpert), and MassARRAY assay which is a MALDI-TOF MS based method.

Results: Among the enrolled patients, 28.36 %, 43.78 %, 47.26 %, 64.68 %, and 85.57 % tested positive by smear, culture, LAMP, Xpert, and MALDI-TOF MS, respectively. MALDI-TOF MS had significantly higher detection rates than the other methods (All P < 0.05). In the 88 culture-positive patients, the positive detection rates for smear, LAMP, Xpert, and MALDI-TOF MS were 43.2 %, 68.2 %, 85.2 %, and 94.3 %, respectively; In 113 culture-negative cases, the positive rates for the above tests were 16.8 %, 31.0 %, 48.7 %, and 78.8 %, respectively. Among the 130 Xpert-positive cases, the positive rates for smear, culture, LAMP, and MALDI-TOF MS were 40.77 %, 57.7 %, 70.77 %, and 98.46 %, respectively; In the 71 Xpert-negative cases, the positive rates for above tests were 5.6 %, 18.3 %, 4.2 %, and 62.0 %, respectively. In the 61 rifampicin-resistant cases, the successful detection rate of MALDI-TOF MS (96.72 %) was significantly higher than that of Xpert (81.97 %) (P < 0.05). The concordance between MALDI-TOF MS and pDST for detecting resistance to 11 anti-tuberculosis drugs ranged from 83.0 % to 98.9 %.

Conclusion: Nucleic acid detection technology using time-of-flight mass spectrometry provides a powerful tool for the rapid diagnosis of tuberculosis and drug-resistant tuberculosis, with advantages of high sensitivity and reliability, warranting further promotion and application.