Background Diagnosing tuberculous serous effusions involving the pleura, peritoneum, and pericardium remains a clinical challenge, primarily due to the paucibacillary nature of such infections and the suboptimal sensitivity of conventional diagnostic modalities. This study aimed to evaluate the diagnostic performance of nanopore-targeted sequencing (NTS) for detecting the Mycobacterium tuberculosis complex (MTBC) in various tuberculous serous effusions, in comparison with standard diagnostic techniques. Our results demonstrated that NTS achieves significantly higher sensitivity while maintaining 100% specificity; additionally, it can simultaneously identify drug resistance-associated mutations, thereby facilitating earlier and more precise clinical decision-making for anti-tuberculosis therapy. Methods A prospective cohort study was conducted on patients presenting with serous effusions of suspected tuberculous origin. Effusion samples (pleural, peritoneal, and pericardial) were collected via thoracentesis, paracentesis, or pericardiocentesis, respectively. All samples underwent a panel of standard tests, including acid-fast bacilli (AFB) smear microscopy, mycobacterial culture, Xpert MTB/RIF assay, and biochemical analyses (including adenosine deaminase ADA activity detection). The diagnostic performance of NTS was systematically evaluated and compared against both microbiological reference standards and composite clinical diagnostic criteria. Results A total of 119 patients with serous effusions were enrolled, including 89 cases of tuberculous effusions and 30 cases of non-tuberculous effusions. The overall positive rates of AFB smear microscopy, MTB culture, and Xpert MTB/RIF assay were markedly low, at 1.12, 8.89, and 12.35%, respectively. NTS exhibited significantly superior sensitivity (61.8%) compared with other conventional microbiological tests (T-SPOT, Xpert MTB/RIF, and MTB culture; all p 0.05) while retaining perfect specificity (100%). Notably, despite the limited sample sizes in the peritoneal and pericardial subgroups, NTS demonstrated notable diagnostic performance in pleural effusion samples, with preliminary findings suggesting potential utility across other serous fluid types. Furthermore, NTS provided valuable genotypic information on drug resistance mutations in MTBC-positive samples. Conclusion NTS demonstrates substantially higher sensitivity than conventional microbiological methods for the rapid identification of tuberculous serous effusions. Its unique ability to directly detect MTBC DNA and drug resistance markers in low-bacillary-load serous fluids (pleural, peritoneal, and pericardial effusions) renders it particularly valuable for the early and precise diagnosis of tuberculous serous effusions, and it has the potential to guide the timely initiation of targeted anti-tuberculosis therapy.
Wang et al. (2026) studied this question.