# Diagnostic value of phenotypic testing combined with molecular biology testing for tuberculosis

## TL;DR

Combining phenotypic and molecular tests with multiple specimen types improves tuberculosis diagnosis accuracy.

## Contribution

The study shows that integrating multiple testing methods and specimen types enhances diagnostic performance for tuberculosis.

## Key findings

- Combining four tests across sputum and BALF achieved an AUROC of 0.917 and 83.3% sensitivity.
- Using multiple tests on a single specimen type outperformed single-method testing.
- Integrated testing improves early diagnosis and treatment guidance for pulmonary tuberculosis.

## Abstract

To evaluate the diagnostic value of combining phenotypic testing with molecular biology testing for tuberculosis, a retrospective study was conducted on 264 presumed pulmonary tuberculosis patients across four hospitals from July 2021 to September 2023. The area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, positive predictive value and negative predictive value were calculated for two phenotypic testing methods—liquid-based sandwich cup acid-fast staining and mycobacterial culture—and two molecular biology testing methods—Boao MTB TaqMan-qPCR and GeneXpert MTB/RIF—using sputum and bronchoalveolar lavage fluid specimens for the diagnosis of active pulmonary tuberculosis. Using the final clinical diagnosis as the reference standard, the combination of both two specimen types and all four testing methods yielded the highest AUROC of 0.917 and sensitivity of 83.3%, significantly outperforming either multiple specimens tested by a single method or multiple methods applied to a single specimen. Moreover, combining multiple tests on either sputum or BALF specimens provided superior diagnostic performance compared with individual tests alone. This study demonstrates that integrating phenotypic and molecular biology testing, across multiple specimen types can provide more accurate guidance for the early diagnosis and treatment of pulmonary tuberculosis.

The online version contains supplementary material available at 10.1038/s41598-026-43218-z.