Use of T-SPOT.TB for the diagnosis of unconventional pleural tuberculosis is superior to ADA in high prevalence areas: a prospective analysis of 601 cases

Evaluation of the diagnostic efficacy of EC-Test for latent tuberculosis infection in ambulatory people with HIV

BACKGROUND

Latent tuberculosis infection (LTBI) co-infected with human immunodeficiency virus (HIV) is more likely to develop into active tuberculosis (ATB), recombinant Mycobacterium tuberculosis fusion protein ESAT6/CFP10 (EC-Test) is a latest developed method for LTBI. Compared with the interferon γ release test assays (IGRAs), the diagnostic performance of EC-Test to LTBI screening in HIV needs to be evaluated.

METHODS

A population-based multicenter prospective study was conducted in Guangxi Province, China. The baseline data was collected and LTBI were measured by QuantiFERON-TB Gold In-Tube (QFT-GIT), EC-Test and T-cell spot of the TB assay (T-SPOT.TB).

RESULTS

A total of 1478 patients were enrolled. when taking T-SPOT.TB as reference, the value of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and consistency that EC-Test to diagnosis LTBI in HIV was 40.42, 97.98, 85.26, 85.04 and 85.06% respectively; when taking QFT-GIT as reference, the value was 36.00, 92.57, 55.10, 85.09 and 81.13%, respectively. When the CD4 + cell count was <200 cells/μl, the accuracies of EC-Test to T-SPOT.TB and QFT-GIT were 87.12 and 88.89%, respectively; when it was 200 ≤ CD4 + ≤ 500 cells/μl, the accuracies of EC-Test was 86.20 and 83.18%, respectively; when the CD4 + cell count >500 cells/μl, the accuracies of EC-Test were 84.29 and 77.94%, respectively. The incidence of adverse reactions in EC-Test was 34.23% and the serious adverse reactions were 1.15%.

CONCLUSION

EC-Test has good consistency compared with IGRAs in detecting LTBI in HIV no matter in different immunosuppression status or different regions, and the safety of EC-Test is also well, suitable for LTBI screening in HIV in high prevalence settings.

Diagnostic Value of CD25, CD69, and CD134 on Tuberculosis-Specific Antigen-Stimulated CD4+ T Cells for Tuberculous Pleurisy

Rapid and accurate methods for the diagnosis of tuberculous pleurisy (TP) are urgently needed. Activation markers of tuberculosis (TB)-reactive T cells are considered promising for the diagnosis of active TB (ATB). Different activation indexes may play different roles in the progression of TB, but there are few reports on T cell activation indicators, except for HLA-DR. Hence, we evaluated the expression of early (CD25 and CD69) and late (CD134) activation markers on TB antigen-stimulated CD4+ T cells in populations with different TB infection status and investigated their diagnostic value for ATB, particularly, for TP. Moreover, we compared the differences in the diagnostic efficacy among the indexes from peripheral blood (PB) and pleural fluid (PF) for TP. The expression of each activation marker was significantly increased in TB-infected populations (patients with ATB and latent TB infection vs. healthy individuals; patients with TP vs. non-TP) and was significantly higher in the PF than in the PB of patients with TP. The diagnostic performance of the coexpressed activation markers was superior to that of single expression markers in the differential diagnosis of ATB and non-TB, with CD25+CD134+ showing the best diagnostic efficiency (AUC: 0.93, 95% CI, 0.87-0.99; sensitivity: 86.7%, 95% CI, 72.5%-94.5%; and specificity: 94.0%, 95% CI, 82.5%-98.4%). Except for TB-IGRA, the activation indexes were more accurate than conventional laboratory methods for ATB diagnosis. In addition, the expression of CD25+CD134+ in PB and PF was the best values for differential diagnosis of TP and NTP, with AUCs of 0.87 (95% CI, 0.77-0.96) and 0.95 (95% CI, 0.90-1.00), respectively. Our study provides information on the diagnostic value of different activation markers for TB and shows that the expression of CD25+CD134+ on CD4+ T cells in PF can serve as a potential marker for TP diagnosis.

Next-Generation TB Vaccines: Progress, Challenges, and Prospects

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is a prevalent global infectious disease and a leading cause of mortality worldwide. Currently, the only available vaccine for TB prevention is Bacillus Calmette-Guérin (BCG). However, BCG demonstrates limited efficacy, particularly in adults. Efforts to develop effective TB vaccines have been ongoing for nearly a century. In this review, we have examined the current obstacles in TB vaccine research and emphasized the significance of understanding the interaction mechanism between MTB and hosts in order to provide new avenues for research and establish a solid foundation for the development of novel vaccines. We have also assessed various TB vaccine candidates, including inactivated vaccines, attenuated live vaccines, subunit vaccines, viral vector vaccines, DNA vaccines, and the emerging mRNA vaccines as well as virus-like particle (VLP)-based vaccines, which are currently in preclinical stages or clinical trials. Furthermore, we have discussed the challenges and opportunities associated with developing different types of TB vaccines and outlined future directions for TB vaccine research, aiming to expedite the development of effective vaccines. This comprehensive review offers a summary of the progress made in the field of novel TB vaccines.

Application of Adenosine Deaminase and γ-Interferon Release Assay in Pleural Fluid for the Diagnosis of Tuberculous Pleural Effusion in Patients Over 40 Years Old

Background

In patients with tuberculous pleural effusion (TPE) of various ages, the diagnostic accuracy of pleural biomarkers varies, and there are insufficient studies specifically in different age groups. Therefore, we investigated the adenosine deaminase cut-off value and its combination with the gamma interferon release assay for the diagnosis of TPE among patients aged ≥40 years.

Methods

A retrospective analysis of 198 patients who underwent medical thoracoscopy and were admitted to the hospital between 2015 and 2020 with exudative pleural effusion and either fever, night sweats, fatigue, cough, or other clinical manifestations was performed. The medical thoracoscopy, ADA, and T-SPOT results were analysed in the pleural fluid. The patients were divided into groups based on age: 18-39, 40-59, and 60-87.

Results

The best cut-off values of ADA were 29.5, 31.5 and 19.5 U/L, respectively, for the aged 18-39, aged 40-87 and aged 60-87 groups. The accuracy of 31.5 U/L was higher than 40 U/L for aged ≥40 years (86 vs 83%). The ADA diagnostic accuracy was higher than that of people under 40 years (83 vs 77%) when cut-off value of ADA was 40 U/L, but the IGRA accuracy was lower than that of people under 40 (87 vs 91%). The sensitivity of ADA or IGRA detection in patients over 40 years was 99%, and the specificity was 78%. The ADA specificity combined with IGRA for TPE was the highest (100%) in the ≥40 age group, and the sensitivity was 69%.

Conclusion

Our study revealed the best cut-off values of ADA for TBE in different age groups. Combining ADA and IGRA in pleural fluid improves the detection rate of TPE in patients over 40 years of age with exudative pleural effusion. ADA combined with IGRA increases specificity, and ADA or IGRA increases sensitivity substantially.

Use of Pleural Fluid Digital PCR Analysis to Improve the Diagnosis of Pleural Tuberculosis

The diagnosis of pleural tuberculosis (TB) remains difficult due to the paucity of Mycobacterium tuberculosis in pleural fluid (PF). This study aimed to improve pleural TB diagnosis using highly sensitive digital PCR (dPCR) technique. A total of 310 patients with evidence of PF were consecutively enrolled, 183 of whom suffered from pleural TB and 127 from non-TB. PF samples were prospectively collected and total DNA was extracted. The copy numbers of M. tuberculosis insertion sequence (IS) 6110 and IS1081 in DNA were quantified using dPCR. The overall area under the curve of IS6110-dPCR was greater than that of IS1081-dPCR (0.85 versus 0.79). PF IS6110 OR IS1081-dPCR (according to their cut-off values, "positive" was defined as either of them was positive, while "negative" was defined as both of them were negative) had higher sensitivity and equal specificity compared with single target-dPCR. The sensitivity of PF IS6110 OR IS1081-dPCR for total, definite, and probable pleural TB was 59.0% (95% CI = 51.5% to 66.2%), 72.8% (95% CI = 62.6% to 81.6%), and 45.1% (95% CI = 34.6% to 55.8%), respectively. Its specificity was 100% (95% CI = 97.1% to 100.0%). PF IS6110 OR IS1081-dPCR showed a higher sensitivity than smear microscopy (57.4% versus 7.1%), mycobacterial culture (55.3% versus 31.8%), and Xpert MTB/RIF (57.6% versus 23.0%). Long antituberculosis treatment time (>1 month) was found to be associated with negative dPCR results in pleural TB patients. This study indicates that PF IS6110 OR IS1081-dPCR is an accurate molecular assay, which is more sensitive than routine etiological tests and has the potential to enhance the definite diagnosis of pleural TB. IMPORTANCE Pleural TB is one of the most frequent causes of pleural effusion, especially in areas with high burden of TB. Due to the paucibacillary nature of the disease, the diagnostic sensitivities of all available bacteriological and molecular tests remain poor. There is an urgent need to develop new efficient methods. Digital PCR (dPCR) is the third generation of PCR that enables the exact quantification of trace nucleic acids in samples. This study evaluates the diagnostic performance of pleural fluid (PF) dPCR analysis for pleural TB, and shows that PF IS6110 OR IS1081-dPCR has a higher sensitivity than routine etiological tests such as smear microscopy, mycobacterial culture, and Xpert MTB/RIF. This work provides a new choice for improving the definite diagnosis of pleural TB.

Diagnostic performance of adenosine deaminase for abdominal tuberculosis: A systematic review and meta-analysis

Background and aim

Abdominal tuberculosis (TB) is a common type of extrapulmonary TB with an insidious onset and non-specific symptoms. Adenosine deaminase (ADA) levels increase rapidly in the early stages of abdominal TB. However, it remains unclear whether ADA serves as a diagnostic marker for abdominal TB.

Methods

We performed a systematic literature search for relevant articles published in PubMed, Web of Science, Cochrane Library, and Embase up to April 2022. First, we used the Quality Assessment of Diagnostic Accuracy Studies tool-2 (QUADAS-2), to evaluate the quality of the included articles. Bivariate and hierarchical summary receiver operating characteristic (HSROC) models were then utilized to analyze pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the receiver operating characteristic curve (AUROC). In addition, we explored a subgroup analysis for potential heterogeneity and publication bias among the included literature.

Results

Twenty-four articles (3,044 participants, 3,044 samples) which met the eligibility criteria were included in this study. The pooled sensitivity and specificity of ADA for abdominal TB detection were 93% [95% confidence interval (CI): 0.89-0.95] and 95% (95% CI: 0.93-0.96), respectively. PLR and NLR were 18.6 (95% CI: 14.0-24.6) and 0.08 (95% CI: 0.05-0.12), respectively. DOR and AUROC were 236 (95% CI: 134-415) and 0.98 (95% CI: 0.96-0.99), respectively. Furthermore, no heterogeneity or publication bias was found.

Conclusions

Our meta-analysis found ADA to be of excellent diagnostic value for abdominal TB and could be used as an auxiliary diagnostic tool.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022297931.

The diagnostic value of T cell spot test and adenosine deaminase in pleural effusion for tuberculous pleurisy: A systematic review and meta-analysis

BACKGROUND

Tuberculous infection of T cell spot test (T-SPOT.TB) and adenosine deaminase (ADA) have a high diagnostic value in pleural effusion for tuberculous pleurisy. However, there were major differences in existing research in regard to the clinical application of the two trials. Therefore, we conducted a meta-analysis to systematically evaluate the diagnostic value of T-SPOT.TB and ADA.

METHODS

Pubmed, Web of Science and Embase databases were searched to compare diagnosis of tuberculous pleurisy by T-SPOT.TB and ADA. The search period was from inception to August 31, 2021. Statistical analyses were performed using Meta-disc 1.4, Revman 5.4 and Stata 16.0. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were determined. Summary receiver operating characteristic (SROC) curves and the area under the curve (AUC) were used to summarize overall diagnostic performance.

RESULTS

10 qualified original research studies were included, with a total of 2075 patients, of which were 1391 tuberculous pleurisy and 684 non-tuberculous pleurisy. The pooled estimates of diagnostic accuracy of T-SPOT.TB were as follows: sensitivity, 0.88 (95% CI: 0.86-0.90; I² = 92.7%); specificity, 0.79 (95% CI: 0.76-0.82; I² = 93.7%); PLR, 4.49 (95% CI: 2.29-8.80; I² = 94.9%); NLR, 0.15 (95% CI: 0.08-0.30; I² = 94.3%), DOR, 35.72 (95% CI: 11.15-114.47; I² = 91.5%). The AUC for SROC was 0.9283 (95% CI: 0.8912-0.9654). The pooled estimates of diagnostic accuracy of ADA were as follows: sensitivity, 0.65 (95% CI: 0.62-0.67; I² = 98.2%); specificity, 0.90 (95% CI: 0.88-0.92; I² = 69.4%); PLR, 6.12 (95% CI: 4.71-7.96; I² = 11.9%); NLR, 0.33 (95% CI: 0.12-0.89; I² = 99.5%), DOR, 23.18 (95% CI: 12.75-42.14; I² = 66.7%). The AUC for SROC was 0.9208 (95% CI: 0.9029-0.9387).

CONCLUSION

Both T-SPOT.TB and ADA had high value in the diagnosis of tuberculous pleurisy. The sensitivity of T-SPOT.TB was higher than ADA, but the specificity of ADA was higher than T-SPOT.TB. On the whole, T-SPOT. TB had similar diagnostic accuracy to ADA.

Insight into diagnosis of pleural tuberculosis with special focus on nucleic acid amplification tests

INTRODUCTION

Pleural tuberculosis (TB) is the archetype of extrapulmonary TB (EPTB), which mainly affects the pleural space and leads to exudative pleural effusion. Diagnosis of pleural TB is a difficult task predominantly due to atypical clinical presentations and sparse bacillary load in clinical specimens.

AREA COVERED

We reviewed the current literature on the globally existing conventional/latest modalities for diagnosing pleural TB. Bacteriological examination (smear/culture), tuberculin skin testing/interferon-γ release assays, biochemical testing, imaging and histopathological/cytological examination are the main modalities. Moreover, nucleic acid amplification tests (NAATs), i.e. loop-mediated isothermal amplification, PCR/multiplex-PCR, nested-PCR, real-time PCR and GeneXpert® MTB/RIF are being utilized. Currently, GeneXpert Ultra, Truenat MTB^TM, detection of circulating Mycobacterium tuberculosis (Mtb) cell-free DNA by NAATs, aptamer-linked immobilized sorbent assay and immuno-PCR (I-PCR) have also been exploited.

EXPERT OPINION

Routine tests are not adequate for effective pleural TB diagnosis. The latest molecular/immunological tests as discussed above, and the other tools, i.e. real-time I-PCR/nanoparticle-based I-PCR and identification of Mtb biomarkers within urinary/serum extracellular vesicles being utilized for pulmonary TB and other EPTB types may also be exploited to diagnose pleural TB. Reliable diagnosis and early therapy would reduce the serious complications associated with pleural TB, i.e. TB empyema, pleural fibrosis, etc.

Pleural Tuberculosis

Pleural tuberculosis (TB) is common and often follows a benign course but may result in serious long-term morbidity. Diagnosis is challenging because of the paucibacillary nature of the condition. Advances in Mycobacterium culture media and PCR-based techniques have increased the yield from mycobacteriologic tests. Surrogate biomarkers perform well in diagnostic accuracy studies but must be interpreted in the context of the pretest probability in the individual patient. Confirming the diagnosis often requires biopsy, which may be acquired through thoracoscopy or image-guided closed pleural biopsy. Treatment is standard anti-TB therapy, with optional drainage and intrapleural fibrinolytics or surgery in complicated cases.

Differential Diagnosis of Latent Tuberculosis Infection and Active Tuberculosis: A Key to a Successful Tuberculosis Control Strategy

As an ancient infectious disease, tuberculosis (TB) is still the leading cause of death from a single infectious agent worldwide. Latent TB infection (LTBI) has been recognized as the largest source of new TB cases and is one of the biggest obstacles to achieving the aim of the End TB Strategy. The latest data indicate that a considerable percentage of the population with LTBI and the lack of differential diagnosis between LTBI and active TB (aTB) may be potential reasons for the high TB morbidity and mortality in countries with high TB burdens. The tuberculin skin test (TST) has been used to diagnose TB for > 100 years, but it fails to distinguish patients with LTBI from those with aTB and people who have received Bacillus Calmette–Guérin vaccination. To overcome the limitations of TST, several new skin tests and interferon-gamma release assays have been developed, such as the Diaskintest, C-Tb skin test, EC-Test, and T-cell spot of the TB assay, QuantiFERON-TB Gold In-Tube, QuantiFERON-TB Gold-Plus, LIAISON QuantiFERON-TB Gold Plus test, and LIOFeron TB/LTBI. However, these methods cannot distinguish LTBI from aTB. To investigate the reasons why all these methods cannot distinguish LTBI from aTB, we have explained the concept and definition of LTBI and expounded on the immunological mechanism of LTBI in this review. In addition, we have outlined the research status, future directions, and challenges of LTBI differential diagnosis, including novel biomarkers derived from Mycobacterium tuberculosis and hosts, new models and algorithms, omics technologies, and microbiota.

The negative impact of increasing age and underlying cirrhosis on the sensitivity of adenosine deaminase in the diagnosis of tuberculous peritonitis: a cross-sectional study in eastern China

BACKGROUND

Our study aimed to evaluate the correlation between the sensitivity of adenosine deaminase (ADA) testing for the diagnosis of tuberculous peritonitis (TBP) and patient age or cirrhosis status.

METHODS

Clinical data for patients clinically diagnosed with TPB (n = 132) or not (n = 147) were assessed. ADA activity was compared among three age groups (< 45 yr, 45-60 yr, and ≥ 60 yr) and among cirrhosis-related subgroups. Cut-off values for the ADA test were analyzed among three patient populations (young non-cirrhotic, n = 97; older non-cirrhotic, n = 115; cirrhotic, n = 67), and validated in a cohort of 259 participants.

RESULTS

According to the multivariate regression analyses, age < 45 yr is highly predictive of TBP risk. The young non-cirrhotic TBP patients had higher ADA activity than the middle-aged or old controls (p < 0.01). Significantly decreased activity and efficacy of ADA were observed in the cirrhotic subgroup/population, regardless of age or cohort. For the above-mentioned two non-cirrhotic populations in the validation cohort, the ADA test showed excellent performance using thresholds of 30.5 IU/L and 20.5 IU/L, with respective sensitivities of 91.1% and 92.6%.

CONCLUSIONS

ADA activity is negatively associated with increasing age and underlying cirrhosis. Optimizing cut-off values for the ADA test can increase its sensitivity in non-cirrhotic individuals older than 45 years.

Extrapulmonary Tuberculosis—An Update on the Diagnosis, Treatment and Drug Resistance

Pathogenic Mycobacterium tuberculosis complex organisms (MTBC) primarily cause pulmonary tuberculosis (PTB); however, MTBC are also capable of causing disease in extrapulmonary (EP) organs, which pose a significant threat to human health worldwide. Extrapulmonary tuberculosis (EPTB) accounts for about 20–30% of all active TB cases and affects mainly children and adults with compromised immune systems. EPTB can occur through hematogenous, lymphatic, or localized bacillary dissemination from a primary source, such as PTB, and affects the brain, eye, mouth, tongue, lymph nodes of neck, spine, bones, muscles, skin, pleura, pericardium, gastrointestinal, peritoneum, and the genitourinary system as primary and/or disseminated disease. EPTB diagnosis involves clinical, radiological, microbiological, histopathological, biochemical/immunological, and molecular methods. However, only culture and molecular techniques are considered confirmatory to differentiate MTBC from any non-tuberculous mycobacteria (NTM) species. While EPTB due to MTBC responds to first-line anti-TB drugs (ATD), drug susceptibility profiling is an essential criterion for addressing drug-resistant EPTB cases (DR-EPTB). Besides antibiotics, adjuvant therapy with corticosteroids has also been used to treat specific EPTB cases. Occasionally, surgical intervention is recommended, mainly when organ damage is debilitating to the patient. Recent epidemiological studies show a striking increase in DR-EPTB cases ranging from 10–15% across various reports. As a neglected disease, significant developments in rapid and accurate diagnosis and better therapeutic interventions are urgently needed to control the emerging EPTB situation globally. In this review, we discuss the recent advances in the clinical diagnosis, treatment, and drug resistance of EPTB.