Background Current clinical tests for mycobacterial pulmonary diseases (MPD), such as pulmonary tuberculosis (PTB) and non-tuberculous mycobacteria pulmonary diseases (NTM-PD), are inaccurate, time-consuming, sputum-dependent, and/or costly. We aimed to develop a simple, rapid and accurate breath test for screening and differential diagnosis of MPD patients in clinical settings. Methods Exhaled breath samples were collected from 142 PTB, 68 NTM-PD and 9 PTB&NTM-PD patients, 93 patients with other pulmonary diseases (OPD) and 181 healthy controls (HC), and tested using the online high-pressure photon ionisation time-of-flight mass spectrometer (HPPI-TOF-MS). Machine learning models were trained and blindly tested for the detection of MPD, PTB, NTM-PD, and the discrimination between PTB and NTM-PD, respectively. Diagnostic performance was evaluated by metrics of sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC). Results The breath PTB detection model achieved a sensitivity of 81.8%, a specificity of 94.3%, an accuracy of 90.7%, and an AUC of 0.957 in the blinded test set (n=150). The corresponding metrics for the NTM-PD detection model were 95.5%, 86.7%, 88.0% and 0.947, respectively. For distinguishing PTB from NTM-PD, the model also achieved good performance with sensitivity, specificity, accuracy, and AUC of 95.5%, 90.9%, 93.9% and 0.974, respectively. 24 potential breath biomarkers associated with MPD were putatively identified and discussed, which included 2-picoline, ethanol, 1-Pentene, etc. Conclusions The developed breathomics-based MPD detection method was demonstrated for the first time with good performance for potential screening and diagnosis of PTB and NTM-PD using a refined operating procedure on the HPPI-TOF-MS platform.

Background: We performed a prospective multicenter diagnostic study to evaluate combined interferon-γ (IFN-γ) and interleukin-2 (IL-2) release assays for detecting active pulmonary tuberculosis (TB) in China. Methods: Adult patients presenting with symptoms suggestive of pulmonary TB were consecutively enrolled in three TB-specialized hospitals. Sputum specimens and blood samples were collected from each participant at enrollment. In vitro measurements of IFN-γ and IL-2 release from Mycobacterium tuberculosis (MTB)-specific antigen-stimulated patient peripheral blood mononuclear cells were conducted using enzyme-linked immunosorbent assays (ELISAs).Results: Between July 2017 and December 2018, a total of 3,245 patients with symptoms suggestive of pulmonary TB were included in the final analysis. Of these patients, 2,536 were diagnosed with active TB, including 1,092 definite and 1,444 clinically diagnosed cases. Overall sensitivity and specificity rates of the IFN-γ release assay were 83.8% and 81.5%, respectively, as compared to IL-2 assay rates yielding greater specificity (94.3%) but lower sensitivity (72.6%). Notably, a parallel-type combination test for IFN-γ/IL-2 provided greatest overall sensitivity (87.9%) but relatively low specificity (79.8%). Meanwhile, a series-type combination test had an overall sensitivity rate of 68.5% that, when stratified by case subgroup, yielded sensitivity rates of 72.1% and 65.8% for definite and clinically diagnosed TB cases, respectively.Conclusion: We developed a new immunological method to differentiate between active TB and other pulmonary diseases. Our data demonstrated that both series-type and parallel-type IFN-γ/IL-2 combination tests may improve diagnosis of active TB cases in different settings. Additionally, the diagnostic accuracy of the series-type combination assay correlated with disease severity in our patient cohort.

BackgroundThe positive rate of pathogenic examination about tuberculosis is low. It is still difficult to achieve early diagnosis for some TB patients. The value of Interferon-gamma release assays (IGRA) in the diagnosis of active tuberculosis remains controversial. The purpose of this multicenter prospective study was to verify and validate the role of TBAg/PHA ratio (TB-specific antigen to phytohaemagglutinin) of T-SPOT.TB assay in diagnosing ATB.MethodsWe prospectively enrolled 2390 suspected pulmonary tuberculosis patients with positive T-SPOT assay results from three tertiary hospitals. ResultsA total of 1549 ATB(active tuberculosis) patients (including 1091 confirmed and 458 probable ATB) and 724 non-tuberculosis (non-TB) patients with positive T-SPOT results were included. The results of this study showed that ESAT-6 and CFP-10 in the T-SPOT.TB assay were significantly higher in the ATB group compared with the non-TB group, while PHA was lower in the ATB group. Results of ESAT-6 , CFP-10 and PHA show a certain diagnostic performance, but moderate sensitivity and specificity. The TBAg/PHA ratio, a further calculation of ESAT-6 , CFP-10 and PHA in T-SPOT.TB assay showed improved performance in the diagnosis of active Tuberculosis. If using the threshold value of 0.2004, the specificity and sensitivity of TBAg/PHA ratio in distinguishing ATB from non-TB were 92.3% and74.4%, PPV was 95.4, PLR was 9.6.ConclusionBy recalculating the results of T-SPOT.TB Assay , the TBAg/PHA ratio shows high prospect value in the diagnosis of active tuberculosis in high prediction areas.