Superiority of TB-PCR Over Conventional and Immunologic Tests for Diagnosing Tuberculosis in Small Bronchoscopic Non-Malignant Specimens

Background In the small non-malignant specimens acquired through respiratory endoscopy, the conventional pathological examination approaches such as acid-fast staining have certain restrictions in the sensitivity of tuberculosis diagnosis. Objective To investigate the sensitizing effect and clinical value of polymerase chain reaction for Mycobacterium tuberculosis (TB-PCR) based on fluorescent probe nucleic acid detection technology in improving the diagnostic positive rate of non-malignant small specimens obtained by respiratory endoscopy. Methods A retrospective analysis was conducted on 729 patients with suspected TB who underwent respiratory endoscopy. All patients provided small non-malignant specimens for TB-PCR, acid-fast staining, and mycobacterial culture. A clinical composite diagnosis served as the gold standard. Diagnostic performance was assessed by accuracy, sensitivity, specificity, and area under the ROC curve (AUC). A subgroup of 113 patients underwent additional testing (T-SPOT. TB, TB-Ab, BALF-G-Xpert, BALF-TB) for extended comparison. Results The AUC, accuracy, sensitivity, specificity, PPV and NPV of TB-PCR in the diagnosis of TB were 0.88 (95% CI: 0.86-0.90), 0.88 (95% CI: 0.85-0.90), 0.99 (95% CI: 0.98-1.00), 0.78 (0.74-0.82), 0.79 (95% CI: 0.75-0.83), 0.99 (95% CI: 0.97-1.00), respectively. Among 729 patients (391 TB+, 338 TB-), TB-PCR showed significantly higher overall diagnostic efficacy (AUC: 0.88) than acid-fast staining (AUC: 0.77, P Conclusion The application of TB-PCR for the detection of lung samples obtained through respiratory endoscopy holds significant clinical application value in the diagnosis of TB. Clinicians should fully recognize the merits and potential of TB-PCR technology, proactively apply it in clinical practice, and choose appropriate detection methods based on the specific conditions of patients.