Evaluation of nucleotide MALDI-TOF MS on bronchoalveolar lavage fluid for pulmonary Tuberculosis: experience from a tertiary hospital in southwestern China

Abstract

To evaluate the diagnostic accuracy of matrix-assisted laser desorption ionization time-of-flight mass spectrometry based on nucleotide (nucleotide MALDI-TOF MS) on bronchoalveolar lavage fluid (BALF) from suspected pulmonary tuberculosis (PTB) patients. A retrospective study was conducted on suspected PTB patients admitted to Chongqing Public Health Medical Center between May 2021 and January 2022. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) values of nucleotide MALDI-TOF MS as well as smear microscopy, Mycobacterium Growth Indicator Tube 960 culture (MGIT 960 culture), and Xpert MTB/RIF were calculated and compared. Total of 343 presumed PTB cases were enrolled. Overall, using the clinical diagnosis as reference, the sensitivity and NPV of nucleotide MALDI-TOF MSwas 71.5% and 43.1%, respectively, significantly higher than smear microscopy (22.6%, 23.2%), MGIT 960 culture (40.6%, 18.9%), Xpert MTB/RIF (40.8%, 27.9%). Furthermore, nucleotide MALDI-TOF MS also outperformed over Xpert MTB/RIF and MGIT 960 culture on smear-negative BALFs. Approximately 50% and 30% of patients benefited from nucleotide MALDI-TOF MS compared with smear and MGIT 960 culture or Xpert MTB/RIF, respectively. This study demonstrated that the analysis of BALF with nucleotide MALDI-TOF MS provided an accurate and promising tool for the early diagnosis of PTB.