Diagnostic performance of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in bronchoalveolar lavage fluid for pulmonary tuberculosis in HIV-infected patients.

Introduction: Pulmonary tuberculosis (PTB) remains a significant health concern, particularly in individuals infected with human immunodeficiency virus (HIV) who are more susceptible to developing active TB disease. Early and accurate diagnosis of TB is crucial for effective treatment and prevention of transmission. This study aims to evaluate the potential of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of bronchoalveolar lavage fluid (BALF) for diagnosis of suspected PTB in HIV-infected patients.

Methods: This retrospective study recruited 60 HIV-infected patients with suspected PTB presenting with respiratory symptoms and abnormal chest radiographs between January 2022 and June 2023. BALF samples were collected and subjected to analysis using MALDI-TOF MS, GeneXpert, acid-fast bacilli (AFB) smear and culture. And their diagnostic performance was compared.

Results: The sensitivity of MALDI⁃TOFMS for diagnosing PTB was 83.3 %, which was better than that of smear 11.9 %, culture 40.5 % or Xpert38.1 % (all  < 0.01). The area under the curve (AUC) value of MALDI⁃TOFMS was 0.889, which was better than that of smear 0.532, culture 0.675 or Xpert 0.690 (all  < 0.01). The katG315 and rpoB-RRDR 511 mutations were detected by the MALDI⁃TOFMS in two patients.

Conclusion: Nucleotide MALDI-TOFMS has a good clinical performance for rapid diagnosis of PTB from BALF samples in HIV infected patients, and detects mutations of TB simultaneously.