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Background: Several novel molecular platforms using nucleic acid amplification tests have been developed for the diagnosis of pulmonary tuberculosis (PTB) and rapid detection of isoniazid and rifampin resistance. Among them, the BD MAX MDR-TB assay (BD MAX) has shown high sensitivity and specificity; however, its diagnostic accuracy performed on bronchoscopy specimens has not been reported., Methods: We retrospectively reviewed the medical records of patients with suspected PTB who underwent bronchoscopy. Patients who underwent BD MAX testing of bronchoscopy specimens were included in the final analysis. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for PTB diagnosis were calculated using a positive culture of Mycobacterium tuberculosis as the reference standard., Results: Of 114 patients, 34 had culture-confirmed PTB. The sensitivity, specificity, PPV, and NPV of BD MAX performed on bronchoscopy specimens for the diagnosis of PTB were 79.4%, 88.8%, 75.0%, and 91.0%, respectively. The sensitivity of BD MAX was superior to that of acid-fast bacillus smear (79.4% vs. 38.2%, p < 0.001)., Conclusion: BD MAX performed on bronchoscopy specimens showed high accuracy for diagnosing PTB. BD MAX can be performed on bronchoscopy specimens in patients with suspected PTB.

Background: Missing isoniazid (INH) resistance during tuberculosis (TB) diagnosis can worsen the outcomes of INH-resistant TB. The BD MAX MDR-TB assay (BD MAX) facilitates the rapid detection of TB and INH and rifampin (RIF) resistance; however, data related to its performance in clinical setting remain limited. Moreover, its effect on treatment outcomes has not yet been studied., Methods: We compared the performance of BD MAX for the detection of INH/RIF resistances to that of the line probe assay (LPA) in patients with pulmonary TB (PTB), using the results of a phenotypic drug sensitivity test as a reference standard. The treatment outcomes of patients who used BD MAX were compared with those of patients who did not., Results: Of the 83 patients included in the study, the BD MAX was used for an initial PTB diagnosis in 39 patients. The sensitivity of BD MAX for detecting PTB was 79.5%. The sensitivity and specificity of BD MAX for INH resistance were both 100%, whereas these were 50.0% and 95.8%, respectively, for RIF resistance. The sensitivity and specificity of BD MAX were comparable to those of LPA. The BD MAX group had a shorter time interval from specimen request to the initiation of anti-TB drugs (2.0 days vs. 5.5 days, p=0.001)., Conclusion: BD MAX showed comparable performance to conventional tests for detecting PTB and INH/RIF resistances. The implementation of BD MAX as a diagnostic tool for PTB resulted in a shorter turnaround time for the initiation of PTB treatment.