Accuracy of cell-free Mycobacterium tuberculosis DNA testing in pleural effusion for diagnosing tuberculous pleurisy: a multicenter cross-sectional study.

BACKGROUND: The diagnosis of tuberculous pleurisy (TP) presents a significant challenge due to the low bacterial load in pleural effusion (PE) samples. Cell-free Mycobacterium tuberculosis DNA (cf-TB) in PE samples is considered an optimal biomarker for diagnosing TP. This study aimed to evaluate the applicability of cf-TB testing across diverse research sites with a relatively large sample size. METHODS: Patients suspected of TP and presenting with clinical symptoms and radiological evidence of PE were consecutively enrolled by treating physicians from 11 research sites across 6 provinces in China between April 2020 and August 2022. Following centrifugation, sediments obtained from PE were used for Xpert MTB/RIF (Xpert) and mycobacterial culture, while the supernatants were subjected to cf-TB testing. This study employed a composite reference standard to definite TP, which was characterized by any positive result for Mycobacterium tuberculosis (MTB) through either PE culture, PE Xpert, or pleural biopsy. RESULTS: A total of 1412 participants underwent screening, and 1344 (95.2%) were subsequently enrolled in this study. Data from 1241 (92.3%) participants were included, comprising 284 with definite TP, 677 with clinically diagnosed TP, and 280 without TP. The sensitivity of cf-TB testing in definite TP was 73.6% (95% CI 68.2-78.4), significantly higher than both Xpert (40.8%, 95% CI 35.3-46.7, P < 0.001) and mycobacterial culture (54.2%, 95% CI 48.4-59.9, P < 0.001). When clinically diagnosed TP was incorporated into the composite reference standard for sensitivity analysis, cf-TB testing showed a sensitivity of 46.8% (450/961, 95% CI 43.7-50.0), significantly higher than both Xpert (116/961, 12.1%, 95% CI 10.2-14.3, P < 0.001) and mycobacterial culture (154/961, 16.0%, 95% CI 13.8-18.5, P < 0.001). The specificities of cf-TB testing, Xpert, and mycobacterial culture were all 100.0%. CONCLUSIONS: The performance of cf-TB testing is significantly superior to that of Xpert and mycobacterial culture methods, indicating that it can be considered as the primary diagnostic approach for improving TP detection. Trial registration The trial was registered on Chictr.org.cn (ChiCTR2000031680, https://www.chictr.org.cn/showproj.html?proj=49316 ).

In vitro and in vivo broad antiviral activity of peptides homologous to fusion glycoproteins of Newcastle disease virus and Marek's disease virus.

Newcastle disease virus (NDV) of paramyxovirus and Marek's disease virus (MDV) of herpesvirus, two of the most serious threats to the poultry industry, can give rise to complex co-infections that hinder diagnosis and prevention. In the current study, two different peptides, derived from the MDV gH (gHH2L) and gB (gBH3), respectively, exhibit antiviral activity against NDV in vitro. The potent inhibitory effect of heptad repeat 2 from fusion glycoprotein of the NDV on MDV infection also has been demonstrated. Plaque formation and embryo infectivity assays confirmed these antiviral results. Furthermore, each tandem peptide consisting of two motifs from different viruses exhibits more potent antiviral activity than the constituent peptides. The current work provides a new strategy for developing novel peptides and vaccines against virus infection and co-infections.