LTBI: latent tuberculosis infection or lasting immune responses to M. tuberculosis? A TBNET consensus statement

A Mathematical Model for the Impact of 3HP and Social Programme Implementation on the Incidence and Mortality of Tuberculosis: Study in Brazil

In this paper, we presented a mathematical model for tuberculosis with treatment for latent tuberculosis cases and incorporated social implementations based on the impact they will have on tuberculosis incidence, cure, and recovery. We incorporated two variables containing the accumulated deaths and active cases into the model in order to study the incidence and mortality rate per year with the data reported by the model. Our objective is to study the impact of social program implementations and therapies on latent tuberculosis in particular the use of once-weekly isoniazid-rifapentine for 12 weeks (3HP). The computational experimentation was performed with data from Brazil and for model calibration, we used the Markov Chain Monte Carlo method (MCMC) with a Bayesian approach. We studied the effect of increasing the coverage of social programs, the Bolsa Familia Programme (BFP) and the Family Health Strategy (FHS) and the implementation of the 3HP as a substitution therapy for two rates of diagnosis and treatment of latent at 1% and 5%. Based of the data obtained by the model in the period 2023-2035, the FHS reported better results than BFP in the case of social implementations and 3HP with a higher rate of diagnosis and treatment of latent in the reduction of incidence and mortality rate and in cases and deaths avoided. With the objective of linking the social and biomedical implementations, we constructed two different scenarios with the rate of diagnosis and treatment. We verified with results reported by the model that with the social implementations studied and the 3HP with the highest rate of diagnosis and treatment of latent, the best results were obtained in comparison with the other independent and joint implementations. A reduction of the incidence by 36.54% with respect to the model with the current strategies and coverage was achieved, and a greater number of cases and deaths from tuberculosis was avoided.

Microneedle patch-based enzyme-linked immunosorbent assay to quantify protein biomarkers of tuberculosis

There is a clinical need for differential diagnosis of the latent versus active stages of tuberculosis (TB) disease by a simple-to-administer test. Alpha-crystallin (Acr) and early secretory antigenic target-6 (ESAT-6) are protein biomarkers associated with the latent and active stages of TB, respectively, and could be used for differential diagnosis. We therefore developed a microneedle patch (MNP) designed for application to the skin to quantify Acr and ESAT-6 in dermal interstitial fluid by enzyme-linked immunosorbent assay (ELISA). We fabricated mechanically strong microneedles made of polystyrene and coated them with capture antibodies against Acr and ESAT-6. We then optimized assay sensitivity to achieve a limit of detection of 750 pg/ml and 3,020 pg/ml for Acr and ESAT-6, respectively. This study demonstrates the feasibility of an MNP-based ELISA for differential diagnosis of latent TB disease.

Cost-Effectiveness Analysis Comparing QuantiFERON-TB Gold Plus Test and Tuberculin Skin Test for the Diagnosis of Latent Tuberculosis Infection in Immunocompetent Subjects in Colombia

OBJECTIVES

To determine the cost-effectiveness of the QuantiFERON-TB Gold Plus (QFT-Plus) test versus the tuberculin skin test in diagnosing latent tuberculosis infection in immunocompetent subjects in the context of the Colombian healthcare system.

METHODS

A hypothetical cohort of 2000 immunocompetent adults vaccinated with Bacillus Calmette-Guérin at birth who are asymptomatic for tuberculosis disease was simulated and included in a decision tree over a horizon of <1 year. The direct healthcare costs related to tests, antituberculosis treatment, and medical care were considered, and diagnostic performance was used as a measure of effectiveness. The incremental cost-effectiveness ratio (ICER) was estimated, and univariate deterministic and probabilistic sensitivity analyses were carried out using 5000 simulations. The currency was the US dollar for the year 2022, with a cost-effectiveness threshold of $6666 USD (1 gross domestic product per capita for 2022).

RESULTS

QFT-Plus was cost-effective with an ICER of $5687 USD for each correctly diagnosed case relative to a threshold of $6666 USD. In the deterministic analysis, QFT-Plus was cost-effective in half of the proposed scenarios. The variable that most affected the ICER was the prevalence of latent tuberculosis and test sensitivities. In the probabilistic analysis, QFT-Plus was cost-effective in 54.74% of the simulated scenarios, and tuberculin skin test was dominant in 13.84%.

CONCLUSIONS

The study provides evidence of the cost-effectiveness of QFT-Plus compared with the tuberculin skin test in diagnosing latent tuberculosis infection in immunocompetent adults in the Colombian context.

Vaccines and Dementia: Part I. Non-Specific Immune Boosting with BCG: History, Ligands, and Receptors

Vaccines such as Bacille Calmette-Guérin (BCG) can apparently defer dementia onset with an efficacy better than all drugs known to date, as initially reported by Gofrit et al. (PLoS One14, e0224433), now confirmed by other studies. Understanding how and why is of immense importance because it could represent a sea-change in how we manage patients with mild cognitive impairment through to dementia. Given that infection and/or inflammation are likely to contribute to the development of dementias such as Alzheimer's disease (Part II of this work), we provide a historical and molecular background to how vaccines, adjuvants, and their component molecules can elicit broad-spectrum protective effects against diverse agents. We review early studies in which poxvirus, herpes virus, and tuberculosis (TB) infections afford cross-protection against unrelated pathogens, a concept known as 'trained immunity'. We then focus on the attenuated TB vaccine, BCG, that was introduced to protect against the causative agent of TB, Mycobacterium tuberculosis. We trace the development of BCG in the 1920 s through to the discovery, by Freund and McDermott in the 1940 s, that extracts of mycobacteria can themselves exert potent immunostimulating (adjuvant) activity; Freund's complete adjuvant based on mycobacteria remains the most potent immunopotentiator reported to date. We then discuss whether the beneficial effects of BCG require long-term persistence of live bacteria, before focusing on the specific mycobacterial molecules, notably muramyl dipeptides, that mediate immunopotentiation, as well as the receptors involved. Part II addresses evidence that immunopotentiation by BCG and other vaccines can protect against dementia development.

Influence of age, IGRA results, and inflammatory markers on mortality in hospitalized tuberculosis patients

INTRODUCTION

Tuberculosis (TB) remains a leading cause of death globally. Identifying the factors associated with mortality during hospitalization for TB is crucial for improving patient outcomes. This study aimed to investigate the potential risk factors, including T-SPOT.TB test results and routine laboratory markers of inflammation, associated with death during hospitalization due to TB.

METHODS

A retrospective analysis was conducted on 244 hospitalized TB patients. Demographic data, clinical characteristics, T-SPOT.TB results, and laboratory parameters were collected. Univariate and multivariate analyses were performed to identify independent risk factors for in-hospital mortality.

RESULTS

Among the patients, 206 survived and 38 died during hospitalization. Multivariate analysis revealed that age (HR: 1.08, 95% CI: 1.02-1.15, p = 0.001), a negative T-SPOT.TB test result (HR: 4.01, 95% CI: 1.78-9.01, p < 0.001), elevated C-reactive protein (CRP) levels (HR: 1.04, 95% CI: 1.01-1.08, p = 0.007), and increased neutrophil-to-lymphocyte ratio (NLR) (HR: 1.04, 95% CI: 1.00-1.07, p = 0.025) were independent risk factors for mortality.

CONCLUSIONS

This study identified age, a negative T-SPOT.TB result, elevated CRP levels, and a high NLR as significant independent risk factors for death in hospitalized TB patients. These findings underscore the importance of these parameters in the risk stratification and management of hospitalized TB patients. Further research is warranted to elucidate the mechanisms behind these associations and to validate these results in different populations.

Latent Tuberculosis Infection and COVID-19: Analysis of a Cohort of Patients from Careggi University Hospital (Florence, Italy)

Data regarding the relationship between coronavirus disease (COVID-19) and active or latent tuberculosis (TB) are discordant. We conducted a retrospective study examining the impact of latent tuberculosis infection (LTBI) on the clinical progression of COVID-19 patients. We selected 213 patients admitted with COVID-19 in a tertiary-level Italian hospital (February-December 2020), who underwent a QuantiFERON-TB test (QFT) and/or chest radiological exam. The population was divided into three groups: (i) QFT negative and without radiological TB sequelae (Neg); (ii) QFT positive and without radiological TB sequelae (Pos); (iii) radiological TB sequelae regardless of QFT result (Seq). In-hospital mortality and oro-tracheal intubation (OTI) showed significantly higher results in the Seq group (Seq 50% vs. Pos 13.3% vs. Neg 9.3%, p < 0.001; Seq 16.7% vs. Pos 6.7% vs. Neg 4.9%, p = 0.045). Considering the Pos and Seq groups' patients as the population with defined LTBI, in-hospital mortality (20/51, 39.2%) and OTI risk (7/51, 13.7%) were statistically higher with respect to patients without LTBI (in-hospital mortality: 15/162, 9.3%, p < 0.001; OTI risk: 8/162, 4.9%, p = 0.023), respectively. Multivariate analysis showed that radiological sequelae and the Charlson Comorbidity Index (CCI) were significantly associated with higher mortality rate; despite the higher CCI of Seq population, we cannot exclude the correlation between COVID-19 in-hospital mortality and the presence of radiological TB sequelae.

Tuberculosis prevention: current strategies and future directions

BACKGROUND

An estimated one fourth of the world's population is infected with Mycobacterium tuberculosis, and 5-10% of those infected develop tuberculosis in their lifetime. Preventing tuberculosis is one of the most underutilized but essential components of curtailing the tuberculosis epidemic. Moreover, current evidence illustrates that tuberculosis manifestations occur along a dynamic spectrum from infection to disease rather than a binary state as historically conceptualized. Elucidating determinants of transition between these states is crucial to decreasing the tuberculosis burden and reaching the END-TB Strategy goals as defined by the WHO. Vaccination, detection of infection, and provision of preventive treatment are key elements of tuberculosis prevention.

OBJECTIVES

This review provides a comprehensive summary of recent evidence and state-of-the-art updates on advancements to prevent tuberculosis in various settings and high-risk populations.

SOURCES

We identified relevant studies in the literature and synthesized the findings to provide an overview of the current state of tuberculosis prevention strategies and latest research developments.

CONTENT

We present the current knowledge and recommendations regarding tuberculosis prevention, with a focus on M. bovis Bacille-Calmette-Guérin vaccination and novel vaccine candidates, tests for latent infection with M. tuberculosis, regimens available for tuberculosis preventive treatment and recommendations in low- and high-burden settings.

IMPLICATIONS

Effective tuberculosis prevention worldwide requires a multipronged approach that addresses social determinants, and improves access to tuberculosis detection and to new short tuberculosis preventive treatment regimens. Robust collaboration and innovative research are needed to reduce the global burden of tuberculosis and develop new detection tools, vaccines, and preventive treatments that serve all populations and ages.

[Management of drug-resistant tuberculosis]

The spread of multidrug-resistant Mycobacterium tuberculosis bacteria jeopardizes tuberculosis control, especially in the WHO Europe region. Following the availability of novel drugs and treatment regimens the World Health Organization has updated management recommendations for patients affected by drug-resistant tuberculosis. These novel recommendations include a significant reduction in the duration of therapy. This review presents the epidemiology and diagnostics of antibiotic-resistant tuberculosis as well as up-to-date treatment recommendations.

A social network analysis model approach to understand tuberculosis transmission in remote rural Madagascar

BACKGROUND

Quality surveillance data used to build tuberculosis (TB) transmission models are frequently unavailable and may overlook community intrinsic dynamics that impact TB transmission. Social network analysis (SNA) generates data on hyperlocal social-demographic structures that contribute to disease transmission.

METHODS

We collected social contact data in five villages and built SNA-informed village-specific stochastic TB transmission models in remote Madagascar. A name-generator approach was used to elicit individual contact networks. Recruitment included confirmed TB patients, followed by snowball sampling of named contacts. Egocentric network data were aggregated into village-level networks. Network- and individual-level characteristics determining contact formation and structure were identified by fitting an exponential random graph model (ERGM), which formed the basis of the contact structure and model dynamics. Models were calibrated and used to evaluate WHO-recommended interventions and community resiliency to foreign TB introduction.

RESULTS

Inter- and intra-village SNA showed variable degrees of interconnectivity, with transitivity (individual clustering) values of 0.16, 0.29, and 0.43. Active case finding and treatment yielded 67%-79% reduction in active TB disease prevalence and a 75% reduction in TB mortality in all village networks. Following hypothetical TB elimination and without specific interventions, networks A and B showed resilience to both active and latent TB reintroduction, while Network C, the village network with the highest transitivity, lacked resiliency to reintroduction and generated a TB prevalence of 2% and a TB mortality rate of 7.3% after introduction of one new contagious infection post hypothetical elimination.

CONCLUSION

In remote Madagascar, SNA-informed models suggest that WHO-recommended interventions reduce TB disease (active TB) prevalence and mortality while TB infection (latent TB) burden remains high. Communities' resiliency to TB introduction decreases as their interconnectivity increases. "Top down" population level TB models would most likely miss this difference between small communities. SNA bridges large-scale population-based and hyper focused community-level TB modeling.

Identification of immune infiltration and cuproptosis-related molecular clusters in tuberculosis

Background

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) infection. Cuproptosis is a novel cell death mechanism correlated with various diseases. This study sought to elucidate the role of cuproptosis-related genes (CRGs) in TB.

Methods

Based on the GSE83456 dataset, we analyzed the expression profiles of CRGs and immune cell infiltration in TB. Based on CRGs, the molecular clusters and related immune cell infiltration were explored using 92 TB samples. The Weighted Gene Co-expression Network Analysis (WGCNA) algorithm was utilized to identify the co-expression modules and cluster-specific differentially expressed genes. Subsequently, the optimal machine learning model was determined by comparing the performance of the random forest (RF), support vector machine (SVM), generalized linear model (GLM), and eXtreme Gradient Boosting (XGB). The predictive performance of the machine learning model was assessed by generating calibration curves and decision curve analysis and validated in an external dataset.

Results

11 CRGs were identified as differentially expressed cuproptosis genes. Significant differences in immune cells were observed in TB patients. Two cuproptosis-related molecular clusters expressed genes were identified. Distinct clusters were identified based on the differential expression of CRGs and immune cells. Besides, significant differences in biological functions and pathway activities were observed between the two clusters. A nomogram was generated to facilitate clinical implementation. Next, calibration curves were generated, and decision curve analysis was conducted to validate the accuracy of our model in predicting TB subtypes. XGB machine learning model yielded the best performance in distinguishing TB patients with different clusters. The top five genes from the XGB model were selected as predictor genes. The XGB model exhibited satisfactory performance during validation in an external dataset. Further analysis revealed that these five model-related genes were significantly associated with latent and active TB.

Conclusion

Our study provided hitherto undocumented evidence of the relationship between cuproptosis and TB and established an optimal machine learning model to evaluate the TB subtypes and latent and active TB patients.

[Treatment of tuberculosis: what is new?]

Never before have so many people around the world been simultaneously affected by tuberculosis. Tuberculosis is the leading cause of death from a bacterial infectious disease worldwide. The World Health Organization's ambitious goal from 2014 of achieving global elimination of tuberculosis does not seem realistic, but on current trends, tuberculosis could be eliminated in the European Union by 2040. Since the beginning of 2022, there have been more innovations for the treatment of tuberculosis than in no other comparable time period before. One month of rifapentine and isoniazid is effective in treating latent tuberculosis infection. However, rifapentine is licensed in the USA but not in the EU and must be imported for individual cases. The duration of the standard treatment for tuberculosis can be shortened to four months but this treatment regimen is also based on rifapentine, in addition to isoniazid, pyrazinamide, and moxifloxacin. The approval of rifapentine in Europe is a much-needed step towards shortening the treatment of tuberculosis. With new drugs an even shorter standard treatment of only 2 months is possible. The treatment of multidrug-resistant/rifampicin-resistant tuberculosis (MDR-/RR-TB) has been shortened to six months, the same length as the standard treatment available in Germany. The combination of bedaquiline, pretomanid, linezolid ± moxifloxacin, cured around 90% of affected patients were cured in studies with a treatment duration of six months. With 19 drugs in clinical trials, the treatment of tuberculosis is expected to continue to improve rapidly in the coming years.

Exploring the link between cardiovascular risk factors and manifestations in latent tuberculosis infection: a comprehensive literature review

BACKGROUND

The global burden of tuberculosis (TB) and cardiovascular disease (CVD) is overt, and the prevalence of this double burden disease remains steadily rising, particularly in low- and middle-income countries. This review aims to explore the association between latent tuberculosis infection (LTBI) and the development of cardiovascular diseases and risk factors. Furthermore, we elucidated the underlying pathophysiological mechanisms that contribute to this relationship.

MAIN BODY

Approximately 25% of the global population carries a dormant form of tuberculosis (TB) infection. During this latent stage, certain subsets of mycobacteria actively reproduce, and recent research suggests that latent TB infection (LTBI) is connected to persistent, long-term low-grade inflammation that can potentially contribute to the development of atherosclerosis and cardiovascular disease (CVD). The presence of LTBI can be confirmed through a positive result on either a tuberculin skin test (TST) or an interferon-gamma release assay (IGRA). Several plausible explanations for the association between LTBI and CVD include increased inflammation, autoimmunity related to heat shock proteins (HSP), and the presence of pathogens within the developing atherosclerotic plaque. The most commonly observed cardiovascular events and risk factors associated with LTBI are acute myocardial infarction, coronary artery stenosis, diabetes mellitus, and hypertension.

CONCLUSIONS

This article highlights the critical role of LTBI in perpetuating the tuberculosis disease cycle and its association with cardiovascular risk factors. Chronic and persistent low inflammation underlined the association. Identifying high-risk LTBI patients and providing targeted preventive medication are crucial strategies for global TB eradication and interrupting transmission chains.

Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a 2023 TBnet/RESIST-TB consensus statement

Drug-resistant tuberculosis is a substantial health-care concern worldwide. Despite culture-based methods being considered the gold standard for drug susceptibility testing, molecular methods provide rapid information about the Mycobacterium tuberculosis mutations associated with resistance to anti-tuberculosis drugs. This consensus document was developed on the basis of a comprehensive literature search, by the TBnet and RESIST-TB networks, about reporting standards for the clinical use of molecular drug susceptibility testing. Review and the search for evidence included hand-searching journals and searching electronic databases. The panel identified studies that linked mutations in genomic regions of M tuberculosis with treatment outcome data. Implementation of molecular testing for the prediction of drug resistance in M tuberculosis is key. Detection of mutations in clinical isolates has implications for the clinical management of patients with multidrug-resistant or rifampicin-resistant tuberculosis, especially in situations when phenotypic drug susceptibility testing is not available. A multidisciplinary team including clinicians, microbiologists, and laboratory scientists reached a consensus on key questions relevant to molecular prediction of drug susceptibility or resistance to M tuberculosis, and their implications for clinical practice. This consensus document should help clinicians in the management of patients with tuberculosis, providing guidance for the design of treatment regimens and optimising outcomes.

Comparison of Two Tuberculosis Infection Tests in a South American Tertiary Hospital: STANDARD F TB-Feron FIA vs. QIAreachTM QuantiFERON-TB

Introduction: Tuberculosis (TB) is one of the most prevalent respiratory diseases in the world. In 2020 there were at least 9.9 million new infections, with 1.5 million deaths. Approximately 10% of people infected with Mycobacterium tuberculosis develop the disease during the first 2 to 5 years after infection. In South America, the diagnosis of Latent Tuberculosis Infections (LTBI) continues to be performed through the Mantoux tuberculin skin test (TST). Objective: The objective of our study was to compare the sensitivity of a new immunofluorescence IGRA test against a widely available IGRA kit on the market. Material and method: Close contact with infectious TB patients, HIV patients, or immunocompromised for another cause were recruited. Two interferon-gamma release assay (IGRA) diagnostic kits were used and compared with TST. Results: 76 patients were recruited, 93.42% were Chilean nationality, and 98.68% of the patients did not have immunosuppression. The sensitivity of the new technique was 88.89%, and the specificity was 92.50% in the study population compared to the IGRA previously used. In the subgroup older than 36 years, the sensitivity was 95.65%, and the specificity was 89.47%. Conclusion: IGRA techniques are a new resource in clinical laboratories to make an accurate diagnosis of LTBI in the region of the Americas. In our population, the greatest benefit of this new IGRA would be observed in people over 36 years of age, where the sensitivity of the technique was like that of the currently available test.

Predictive performance of interferon-gamma release assays and the tuberculin skin test for incident tuberculosis: an individual participant data meta-analysis

BACKGROUND

Evidence on the comparative performance of purified protein derivative tuberculin skin tests (TST) and interferon-gamma release assays (IGRA) for predicting incident active tuberculosis (TB) remains conflicting. We conducted an individual participant data meta-analysis to directly compare the predictive performance for incident TB disease between TST and IGRA to inform policy.

METHODS

We searched Medline and Embase from 1 January 2002 to 4 September 2020, and studies that were included in previous systematic reviews. We included prospective longitudinal studies in which participants received both TST and IGRA and estimated performance as hazard ratios (HR) for the development of all diagnoses of TB in participants with dichotomised positive test results compared to negative results, using different thresholds of positivity for TST. Secondary analyses included an evaluation of the impact of background TB incidence. We also estimated the sensitivity and specificity for predicting TB. We explored heterogeneity through pre-defined sub-group analyses (e.g. country-level TB incidence). Publication bias was assessed using funnel plots and Egger's test. This review is registered with PROSPERO, CRD42020205667.

FINDINGS

We obtained data from 13 studies out of 40 that were considered eligible (N = 32,034 participants: 36% from countries with TB incidence rate ≥100 per 100,000 population). All reported data on TST and QuantiFERON Gold in-Tube (QFT-GIT). The point estimate for the TST was highest with higher cut-offs for positivity and particularly when stratified by bacillus Calmette-Guérin vaccine (BCG) status (15 mm if BCG vaccinated and 5 mm if not [TST^{5/15 mm}]) at 2.88 (95% CI 1.69-4.90). The pooled HR for QFT-GIT was higher than for TST at 4.15 (95% CI 1.97-8.75). The difference was large in countries with TB incidence rate <100 per 100,000 population (HR 10.38, 95% CI 4.17-25.87 for QFT-GIT VS. HR 5.36, 95% CI 3.82-7.51 for TST^{5/15 mm}) but much of this difference was driven by a single study (HR 5.13, 95% CI 3.58-7.35 for TST^{5/15 mm} VS. 7.18, 95% CI 4.48-11.51 for QFT-GIT, when excluding the study, in which all 19 TB cases had positive QFT-GIT results). The comparative performance was similar in the higher burden countries (HR 1.61, 95% CI 1.23-2.10 for QFT-GIT VS. HR 1.72, 95% CI 0.98-3.01 for TST^{5/15 mm}). The predictive performance of both tests was higher in countries with TB incidence rate <100 per 100,000 population. In the lower TB incidence countries, the specificity of TST (76% for TST^{5/15 mm}) and QFT-GIT (74%) for predicting active TB approached the minimum World Health Organization target (≥75%), but the sensitivity was below the target of ≥75% (63% for TST^{5/15 mm} and 65% for QFT-GIT). The absolute differences in positive and negative predictive values between TST^{15 mm} and QFT-GIT were small (positive predictive values 2.74% VS. 2.46%; negative predictive values 99.42% VS. 99.52% in low-incidence countries). Egger's test did not show evidence of publication bias (0.74 for TST^{15 mm} and p = 0.68 for QFT-GIT).

INTERPRETATION

IGRA appears to have higher predictive performance than the TST in low TB incidence countries, but the difference was driven by a single study. Any advantage in clinical performance may be small, given the numerically similar positive and negative predictive values. Both IGRA and TST had lower performance in countries with high TB incidence. Test choice should be contextual and made considering operational and likely clinical impact of test results.

FUNDING

YH, IA, and MXR were supported by the National Institute for Health and Care Research (NIHR), United Kingdom (RP-PG-0217-20009). MQ was supported by the Medical Research Council [MC_UU_00004/07].

High accuracy of recombinant fusion protein early secretory antigenic target protein 6-culture filtrate protein 10 skin test for the detection of tuberculosis infection: a phase III, multi-centered, double-blind, hospital-based, randomized controlled trial

OBJECTIVES

To verify the diagnostic utility of recombinant fusion protein ESAT6-CPF10 (EC), a novel skin test reagent to detect Mycobacterium tuberculosis infection.

METHODS

A multi-centered, double-blind, randomized controlled trial was conducted from December 17, 2015, to March 2, 2018. Participants involved in this study included those with active tuberculosis (TB), suspected pulmonary TB, or non-TB pulmonary disease. Each participant received three tests simultaneously, TB-specific enzyme-linked immunospot assay (T-SPOT.TB), tuberculin skin test (TST), and EC skin test (ECST), and adverse events were reported.

RESULTS

Diagnostic accuracy was analyzed using data from 1085 protocol-compliant participants. The sensitivities of the ECST, TST, and T-SPOT.TB were 91.2% (95% CI, 89.0-93.2%), 91.4% (95% CI, 89.1-93.3%), and 92.1% (95% CI, 89.9-93.9%), respectively. The specificities of the ECST (69.7%, 95% CI, 64.5-74.5%) and T-SPOT.TB (76.1%, 95% CI, 71.2-80.5%) were significantly higher than the TST (54.4%, 95% CI, 48.9-59.7%). The agreements between ECST and TST (kappa = 0.632) and between ECST and T-SPOT.TB (kappa = 0.780) were substantial. No severe adverse event was reported.

CONCLUSION

The diagnostic performance of the ECST was close to the T-SPOT.TB assay in the detection of TB infection and indicated good potential for clinical application in common scenarios.

Sex and Gender Differences in Tuberculosis Pathogenesis and Treatment Outcomes

Tuberculosis remains a daunting public health concern in many countries of the world. A consistent observation in the global epidemiology of tuberculosis is an excess of cases of active pulmonary tuberculosis among males compared with females. Data from both humans and animals also suggest that males are more susceptible than females to develop active pulmonary disease. Similarly, male sex has been associated with poor treatment outcomes. Despite this growing body of evidence, little is known about the mechanisms driving sex bias in tuberculosis disease. Two dominant hypotheses have been proposed to explain the predominance of active pulmonary tuberculosis among males. The first is based on the contribution of biological factors, such as sex hormones and genetic factors, on host immunity during tuberculosis. The second is focused on non-biological factors such as smoking, professional exposure, and health-seeking behaviors, known to be influenced by gender. In this chapter, we review the literature regarding these two prevailing hypotheses by presenting human but also experimental animal studies. In addition, we presented studies aiming at examining the impact of sex and gender on other clinical forms of tuberculosis such as latent tuberculosis infection and extrapulmonary tuberculosis, which both appear to have their own specificities in relation to sex. We also highlighted potential intersections between sex and gender in the context of tuberculosis and shared future directions that could guide in elucidating mechanisms of sex-based differences in tuberculosis pathogenesis and treatment outcomes.

Progress on diagnosis and treatment of latent tuberculosis infection

One fourth of the global population has been infected with Mycobacterium tuberculosis, and about 5%-10% of the infected individuals with latent tuberculosis infection (LTBI) will convert to active tuberculosis (ATB). Correct diagnosis and treatment of LTBI are important in ending the tuberculosis epidemic. Current methods for diagnosing LTBI, such as tuberculin skin test (TST) and interferon-γ release assay (IGRA), have limitations. Some novel biomarkers, such as transcriptome derived host genes in peripheral blood cells, will help to distinguish LTBI from ATB. More emphasis should be placed on surveillance in high-risk groups, including patients with HIV infection, those using biological agents, organ transplant recipients and those in close contact with ATB patients. For those with LTBI, treatment should be based on the risk of progression to ATB and the potential benefit. Prophylactic LTBI regimens include isoniazid monotherapy for 6 or 9 months, rifampicin monotherapy for 4 months, weekly rifapentine plus isoniazid for 3 months (3HP regimen) and daily rifampicin plus isoniazid for 3 months (3HR regimen). The success of the one month rifapentine plus isoniazid daily regimen (1HP regimen) suggests the feasibility of an ultra-short treatment strategy although its efficacy needs further assessment. Prophylactic treatment of LTBI in close contact with MDR-TB patients is another challenge, and the regimens include new anti-tuberculosis drugs such as bedaquiline, delamanid, fluoroquinolone and their combinations, which should be carefully evaluated. This article summarizes the current status of diagnosis and treatment of LTBI and its future development direction.

Réactivation de tuberculose après traitement immunomodulateur pour une infection sévère à SARS-CoV-2

Nous rapportons deux cas de réactivation tuberculeuse après COVID-19 sous corticostéroïdes et tocilizumab. Ils ont présenté une lymphopénie, des signes cliniques limités, des signes radiologiques inhabituels mais des prélèvements microbiologiques positifs. Le dépistage de l'infection tuberculeuse latente (ITL) étant inapproprié dans ce contexte, il faudrait discuter de la traiter systématiquement chez des patients les plus à risque en cas de traitement immunomodulateur.

Tuberculosis Infection in Children and Adolescents

The burden of tuberculosis (TB) in children and adolescents remains very significant. Several million children and adolescents are infected with TB each year worldwide following exposure to an infectious TB case and the risk of progression from TB infection to tuberculosis disease is higher in this group compared to adults. This review describes the risk factors for TB infection in children and adolescents. Following TB exposure, the risk of TB infection is determined by a combination of index case characteristics, contact features, and environmental determinants. We also present the recently recommended approaches to diagnose and treat TB infection as well as novel tests for infection. The tests for TB infection have limitations and diagnosis still relies on an indirect immunological assessment of cellular immune response to Mycobacterium tuberculosis antigens using immunodiagnostic testing. It is recommended that TB exposed children and adolescents and those living with HIV receive TB preventive treatment (TPT) to reduce the risk of progression to TB disease. Several TPT regimens of similar effectiveness and safety are now available and recommended by the World Health Organisation.

Interferon-gamma Release Assay-positive Granulomatous Interstitial Nephritis in a Patient with a History of Diffuse Large B Cell Lymphoma

Tuberculosis is a common etiology of granulomatous interstitial nephritis (GIN). However, the absence of evidence of lung involvement and lack of mycobacterial isolation in cultures make the etiological diagnosis and treatment decision challenging. We herein report a 46-year-old man with severe renal failure, a persistent fever, and a history of lymphoma. A renal biopsy exhibited GIN. Despite no evidence of tuberculosis except for a positive interferon-gamma release assay (IGRA), the patient was successfully treated with anti-tuberculosis drugs. Our case suggests that anti-tuberculosis therapy should be considered for patients with IGRA-positive GIN after excluding other etiologies.

Tuberkulose im Erwachsenenalter

Die Tuberkulose ist in Deutschland eine seltene, überwiegend gut behandelbare Erkrankung. Weltweit ist sie eine der häufigsten Infektionserkrankungen mit ca. 10 Millionen Neuerkrankungen/Jahr. Auch bei einer niedrigen Inzidenz in Deutschland bleibt Tuberkulose insbesondere aufgrund der internationalen Entwicklungen und Migrationsbewegungen eine wichtige Differenzialdiagnose. In Deutschland besteht, aufgrund der niedrigen Prävalenz der Erkrankung und der damit verbundenen abnehmenden klinischen Erfahrung, ein Informationsbedarf zu allen Aspekten der Tuberkulose und ihrer Kontrolle. Diese Leitlinie umfasst die mikrobiologische Diagnostik, die Grundprinzipien der Standardtherapie, die Behandlung verschiedener Organmanifestationen, den Umgang mit typischen unerwünschten Arzneimittelwirkungen, die Besonderheiten in der Diagnostik und Therapie resistenter Tuberkulose sowie die Behandlung bei TB-HIV-Koinfektion. Sie geht darüber hinaus auf Versorgungsaspekte und gesetzliche Regelungen wie auch auf die Diagnosestellung und präventive Therapie einer latenten tuberkulösen Infektion ein. Es wird ausgeführt, wann es der Behandlung durch spezialisierte Zentren bedarf.

Die Aktualisierung der S2k-Leitlinie „Tuberkulose im Erwachsenenalter“ soll allen in der Tuberkuloseversorgung Tätigen als Richtschnur für die Prävention, die Diagnose und die Therapie der Tuberkulose dienen und helfen, den heutigen Herausforderungen im Umgang mit Tuberkulose in Deutschland gewachsen zu sein.

MicroRNAs as immune regulators and biomarkers in tuberculosis

Tuberculosis (TB), which is caused by Mycobacterium tuberculosis (Mtb), is one of the most lethal infectious disease worldwide, and it greatly affects human health. Some diagnostic and therapeutic methods are available to effectively prevent and treat TB; however, only a few systematic studies have described the roles of microRNAs (miRNAs) in TB. Combining multiple clinical datasets and previous studies on Mtb and miRNAs, we state that pathogens can exploit interactions between miRNAs and other biomolecules to avoid host mechanisms of immune-mediated clearance and survive in host cells for a long time. During the interaction between Mtb and host cells, miRNA expression levels are altered, resulting in the changes in the miRNA-mediated regulation of host cell metabolism, inflammatory responses, apoptosis, and autophagy. In addition, differential miRNA expression can be used to distinguish healthy individuals, patients with TB, and patients with latent TB. This review summarizes the roles of miRNAs in immune regulation and their application as biomarkers in TB. These findings could provide new opportunities for the diagnosis and treatment of TB.

Selection of the cutoff value of the tuberculin skin test for diagnosing students who need preventive treatment: A school-based cross-sectional study

Objective

Tuberculosis outbreaks in schools are common in China. This study aimed to introduce and evaluate a new screening process to help control outbreaks.

Methods

Screening information of students in three schools with tuberculosis outbreaks was collected. QuantiFERON-TB gold in-tube (QFT) results were used as the reference standard to determine the cutoff value of the tuberculin skin test (TST) for diagnosing students who need to have preventive medication.

Results

A total of 1,232 students and teachers from three different schools that all had more than three student patients with tuberculosis were included in this study. In total, 308 (25.0%) students had an induration diameter ≥10 mm; among students in a class different from the index case, the infection rate was 24.4% (264/1,084), which was lower than the rate among students in the same class (29.7%) (P = 0.157). Students in the same class as the index tuberculosis case had a much higher QFT positivity compared to those in a different class (58.1% vs. 7.7%, P < 0.0001). Diagnostic agreement between TST ≥10 mm and QFT was 36.6%. The diagnostic value reached the highest when the induration diameter of TST was ≥9 mm, with a sensitivity and specificity of 94.1% (95% CI: 89.4%–97.1%) and 27.6% (95% CI: 24.9%–30.4%), respectively. The area under the curve (AUC) was 0.664 (95% CI: 0.637–0.690, P < 0.0001).

Conclusion

In tuberculosis outbreaks in schools, if there are three or more cases of students with tuberculosis in a class or if the moderate or strong TST positivity rate is much higher than the normal range in the region, attention should be paid to those with moderately positive TST results. Interferon-gamma release assays (IGRAs) are recommended to be conducted following TST on the day of reading the results, especially among students sharing the same class with the index case. In resource-poor areas lacking IGRAs, the induration diameter of TST can be appropriately reduced from 15 to 9 mm to enhance the sensitivity of TST.

Progressive Host-Directed Strategies to Potentiate BCG Vaccination Against Tuberculosis

The pursuit to improve the TB control program comprising one approved vaccine, M. bovis Bacille Calmette-Guerin (BCG) has directed researchers to explore progressive approaches to halt the eternal TB pandemic. Mycobacterium tuberculosis (M.tb) was first identified as the causative agent of TB in 1882 by Dr. Robert Koch. However, TB has plagued living beings since ancient times and continues to endure as an eternal scourge ravaging even with existing chemoprophylaxis and preventive therapy. We have scientifically come a long way since then, but despite accessibility to the standard antimycobacterial antibiotics and prophylactic vaccine, almost one-fourth of humankind is infected latently with M.tb. Existing therapeutics fail to control TB, due to the upsurge of drug-resistant strains and increasing incidents of co-infections in immune-compromised individuals. Unresponsiveness to established antibiotics leaves patients with no therapeutic possibilities. Hence the search for an efficacious TB immunization strategy is a global health priority. Researchers are paving the course for efficient vaccination strategies with the radically advanced operation of core principles of protective immune responses against M.tb. In this review; we have reassessed the progression of the TB vaccination program comprising BCG immunization in children and potential stratagems to reinforce BCG-induced protection in adults.

Pediatric Tuberculosis Management: A Global Challenge or Breakthrough?

Managing pediatric tuberculosis (TB) remains a public health problem requiring urgent and long-lasting solutions as TB is one of the top ten causes of ill health and death in children as well as adolescents universally. Minors are particularly susceptible to this severe illness that can be fatal post-infection or even serve as reservoirs for future disease outbreaks. However, pediatric TB is the least prioritized in most health programs and optimal infection/disease control has been quite neglected for this specialized patient category, as most scientific and clinical research efforts focus on developing novel management strategies for adults. Moreover, the ongoing coronavirus pandemic has meaningfully hindered the gains and progress achieved with TB prophylaxis, therapy, diagnosis, and global eradication goals for all affected persons of varying age bands. Thus, the opening of novel research activities and opportunities that can provide more insight and create new knowledge specifically geared towards managing TB disease in this specialized group will significantly improve their well-being and longevity.

The effect of BCG vaccination and risk factors for latent tuberculosis infection among college freshmen in China

OBJECTIVES

In this study, we aimed to verify whether Bacillus Calmette-Guérin (BCG) can protect first-year college students against Mycobacterium tuberculosis (MTB) infection by the recombinant fusion protein ESAT6-CFP10 skin test (ECST) or the tuberculin skin test (TST).

METHODS

We conducted a cross-sectional study to assess risk factors for latent tuberculosis infection (LTBI). Vaccine effectiveness of BCG against LTBI, measured by ECST and TST separately, was assessed using multivariable logistic regression.

RESULTS

A total of 7351 college freshmen accepted ECST, whereas 7228 accepted TST. A total of 263 (3.58%) tested positive with ECST and 581 (8.04%) tested positive with TST. BCG was significantly associated with LTBI (ECST: adjusted odds ratio (aOR) = 0.26; 95% CI 0.09 to 0.73; TST: aOR = 0.25; 95% CI 0.13 to 0.49). The BCG protective effect on freshmen living in rural areas (ECST: aOR = 0.16; 95% CI 0.04 to 0.55; TST: aOR = 0.12; 95% CI 0.04 to 0.33) is better than that of freshmen living in cities (ECST: aOR = 0.53; 95% CI 0.07 to 4.03; TST: aOR = 0.44; 95% CI 0.17 to 1.16).

CONCLUSIONS

Protection against LTBI was strongly associated with BCG vaccination. A novel skin test (ECST) may underestimate the protective effects of BCG in college freshmen. BCG has better protection in areas with a slightly higher incidence of LTBI.

Effect of different interventions for latent tuberculosis infections in China: a model-based study

BACKGROUND

Tuberculosis (TB) has a serious impact on people's health. China is one of 30 countries that has a high TB burden. As the currently decreasing speed of the incidence of TB, the WHO's goal of "End TB Strategy" is hard to achieve by 2035. As a result, a SEIR model that determines the impact of different tuberculosis preventive treatments (TPTs) in different age groups, and the effect of different interventions on latent TB infections (LTBIs) in China is developed.

METHODS

A Susceptible-Exposed-Infectious-Recovered (SEIR) model was established. Goodness-of-fit tests were used to assess model performance. Predictive analysis was used to assess the effect of different interventions on LTBIs and achieving the goals of the "End TB Strategy".

RESULTS

The Chi-square test indicated the model provided a good statistical fit to previous data on the incidence of TB (χ² = 0.3085, p > 0.999). The 1HP treatment regimen (daily rifapentine + isoniazid for 4 weeks) was most effective in reducing the number of TB cases by 2035. The model indicated that several strategies could achieve the 2035 target of the "End TB Strategy": completion of active case finding (ACF) for LTBI and TPT nation-wide within 5 years; completion of ACF for LTBIs and TPT within 2 years in high-incidence areas; completion of TPT in the elderly within 2 years; or introduction of a new vaccine in which the product of annual doses and vaccine efficiency in the three age groups above 14 years old reached 10.5 million.

CONCLUSION

The incidence of TB in China declined gradually from 2005 to 2019. Implementation of ACF for LTBIs and TPT nation-wide or in areas with high incidence, in the elderly, or administration of a new and effective vaccine could greatly reduce the number of TB cases and achieve the 2035 target of the "End TB Strategy" in China.

Optimal Detection of Latent Mycobacterium tuberculosis Infection by Combined Heparin-Binding Hemagglutinin (HBHA) and Early Secreted Antigenic Target 6 (ESAT-6) Whole-Blood Interferon Gamma Release Assays

Optimal detection of latent tuberculosis (TB) infection (LTBI) remains a challenge, although it is essential to reach the goal of TB elimination. Our objective was to develop and clinically evaluate a user-friendly, 24-h, whole-blood (WB) interferon gamma (IFN-γ) release assay (IGRA) improving the detection of LTBI, compared to available tests. One milliliter of blood was divided into four aliquots and in vitro stimulated for 24 h with two different stage-specific mycobacterial antigens, i.e., heparin-binding hemagglutinin (HBHA) and early secreted antigenic target 6 (ESAT-6), a latency-associated antigen and a bacterial replication-related antigen, respectively, in addition to positive and negative controls. Clinical evaluation was performed on two independent cohorts of carefully selected subjects, i.e., a training cohort of 83 individuals and a validation cohort of 69 individuals. Both cohorts comprised LTBI subjects (asymptomatic people with a positive tuberculin skin test result and potential exposure to TB index cases), patients with active TB (aTB), and noninfected controls. The sensitivity and specificity of the WB-HBHA-IGRA to identify LTBI subjects among asymptomatic individuals were 93%. Combining the results in response to HBHA and ESAT-6 allowed us to identify LTBI subgroups. One group, with IFN-γ responses to HBHA only, was easily differentiated from patients with aTB. The other group, responding to both antigens like the aTB group, is likely at risk to reactivate the infection and should be prioritized for prophylactic anti-TB treatment. The combined WB-IGRA may be offered to clinicians for the selection of LTBI subjects to benefit from prophylactic treatment.

Immuno-Diagnosis of Active Tuberculosis by a Combination of Cytokines/Chemokines Induced by Two Stage-Specific Mycobacterial Antigens: A Pilot Study in a Low TB Incidence Country

Active tuberculosis (aTB) remains a major killer from infectious disease, partially due to delayed diagnosis and hence treatment. Classical microbiological methods are slow and lack sensitivity, molecular techniques are costly and often unavailable. Moreover, available immuno-diagnostic tests lack sensitivity and do not differentiate between aTB and latent TB infection (LTBI). Here, we evaluated the performance of the combined measurement of different chemokines/cytokines induced by two different stage-specific mycobacterial antigens, Early-secreted-antigenic target-6 (ESAT-6) and Heparin-binding-haemagglutinin (HBHA), after a short in vitro incubation of either peripheral blood mononuclear cells (PBMC) or whole blood (WB). Blood samples were collected from a training cohort comprising 22 aTB patients, 22 LTBI subjects and 17 non-infected controls. The concentrations of 13 cytokines were measured in the supernatants. Random forest analysis identified the best markers to differentiate M. tuberculosis-infected from non-infected subjects, and the most appropriate markers to differentiate aTB from LTBI. Logistic regression defined predictive abilities of selected combinations of cytokines, first on the training and then on a validation cohort (17 aTB, 27 LTBI, 25 controls). Combining HBHA- and ESAT-6-induced IFN-γ concentrations produced by PBMC was optimal to differentiate infected from non-infected individuals in the training cohort (100% correct classification), but 2/16 (13%) patients with aTB were misclassified in the validation cohort. ESAT-6-induced-IP-10 combined with HBHA-induced-IFN-γ concentrations was selected to differentiate aTB from LTBI, and correctly classified 82%/77% of infected subjects as aTB or LTBI in the training/validation cohorts, respectively. Results obtained on WB also selected ESAT-6- and HBHA-induced IFN-γ concentrations to provided discrimination between infected and non-infected subjects (89%/90% correct classification in the training/validation cohorts). Further identification of aTB patients among infected subjects was best achieved by combining ESAT-6-induced IP-10 with HBHA-induced IL-2 and GM-CSF. Among infected subjects, 90%/93% of the aTB patients were correctly identified in the training/validation cohorts. We therefore propose a two steps strategy performed on 1 mL WB for a rapid identification of patients with aTB. After elimination of most non-infected subjects by combining ESAT-6 and HBHA-induced IFN-γ, the combination of IP-10, IL-2 and GM-CSF released by either ESAT-6 or HBHA correctly identifies most patients with aTB.

The Biological and Clinical Aspects of a Latent Tuberculosis Infection

Tuberculosis (TB), caused by bacilli from the Mycobacterium tuberculosis complex, remains a serious global public health problem, representing one of the main causes of death from infectious diseases. About one quarter of the world’s population is infected with Mtb and has a latent TB infection (LTBI). According to the World Health Organization (WHO), an LTBI is characterized by a lasting immune response to Mtb antigens without any TB symptoms. Current LTBI diagnoses and treatments are based on this simplified definition, although an LTBI involves a broad range of conditions, including when Mtb remains in the body in a persistent form and the immune response cannot be detected. The study of LTBIs has progressed in recent years; however, many biological and medical aspects of an LTBI are still under discussion. This review focuses on an LTBI as a broad spectrum of states, both of the human body, and of Mtb cells. The problems of phenotypic insusceptibility, diagnoses, chemoprophylaxis, and the necessity of treatment are discussed. We emphasize the complexity of an LTBI diagnosis and its treatment due to its ambiguous nature. We consider alternative ways of differentiating an LTBI from active TB, as well as predicting TB reactivation based on using mycobacterial “latency antigens” for interferon gamma release assay (IGRA) tests and the transcriptomic analysis of human blood cells.

Protection against tuberculosis by Bacillus Calmette-Guérin (BCG) vaccination: A historical perspective

Bacillus Calmette-Guérin (BCG) was developed exactly 100 years ago, and it is still the only licensed tuberculosis (TB) vaccine and the most frequently administered of all vaccines worldwide. Despite universal vaccination policies in TB-endemic settings, the burden of TB remains high. Although BCG protects against Mycobacterium tuberculosis infection and TB disease, the level of protection varies greatly between age groups and settings. In this review, we present a historical perspective and describe the evidence for BCG's ability to protect against TB as well as the factors that influence protection. We also present the immunological mechanisms through which BCG vaccination induces protection, focusing on T cell, B cell, and innate immunity. Finally, we discuss several possibilities to boost BCG's efficacy, including alternative vaccination routes, BCG revaccination, and use of recombinant BCG vaccines, and describe the knowledge gaps that exist with respect to BCG's protection against TB.

Multi-Dimensionality Immunophenotyping Analyses of MAIT Cells Expressing Th1/Th17 Cytokines and Cytotoxic Markers in Latent Tuberculosis Diabetes Comorbidity

Mucosal-associated invariant T (MAIT) cells are innate like, and play a major role in restricting disease caused by Mycobacterium tuberculosis (Mtb) disease before the activation of antigen-specific T cells. Additionally, the potential link and synergistic function between diabetes mellitus (DM) and tuberculosis (TB) has been recognized for a long time. However, the role of MAIT cells in latent TB (LTB) DM or pre-DM (PDM) and non-DM (NDM) comorbidities is not known. Hence, we examined the frequencies (represented as geometric means, GM) of unstimulated (UNS), mycobacterial (purified protein derivative (PPD) and whole-cell lysate (WCL)), and positive control (phorbol myristate acetate (P)/ionomycin (I)) antigen stimulated MAIT cells expressing Th1 (IFNγ, TNFα, and IL-2), Th17 (IL-17A, IL-17F, and IL-22), and cytotoxic (perforin (PFN), granzyme (GZE B), and granulysin (GNLSN)) markers in LTB comorbidities by uniform manifold approximation (UMAP) and flow cytometry. We also performed a correlation analysis of Th1/Th17 cytokines and cytotoxic markers with HbA1c, TST, and BMI, and diverse hematological and biochemical parameters. The UMAP analysis demonstrated that the percentage of MAIT cells was higher; T helper (Th)1 cytokine and cytotoxic (PFN) markers expressions were different in LTB-DM and PDM individuals in comparison to the LTB-NDM group on UMAP. Similarly, no significant difference was observed in the geometric means (GM) of MAIT cells expressing Th1, Th17, and cytotoxic markers between the study population under UNS conditions. In mycobacterial antigen stimulation, the GM of Th1 (IFNγ (PPD and WCL), TNFα (PPD and WCL), and IL-2 (PPD)), and Th17 (IL-17A, IL-17F, and IL-22 (PPD and/or WCL)) cytokines were significantly elevated and cytotoxic markers (PFN, GZE B, and GNLSN (PPD and WCL)) were significantly reduced in the LTB-DM and/or PDM group compared to the LTB-NDM group. Some of the Th1/Th17 cytokines and cytotoxic markers were significantly correlated with the parameters analyzed. Overall, we found that different Th1 cytokines and cytotoxic marker population clusters and increased Th1 and Th17 (IL-17A, IL-22) cytokines and diminished cytotoxic markers expressing MAIT cells are associated with LTB-PDM and DM comorbidities.

Infectious risk in multiple sclerosis patients treated with disease-modifying therapies: A three-year observational cohort study

Background

The disease-modifying therapies (DMTs) largely used in multiple sclerosis (MS) may result in higher infectious risk.

Objective

We aimed to investigate the infectious risk in DMT-treated MS patients.

Methods

MS patients were evaluated for infectious risk before starting, switching or during DMT.

Results

In this three-year observational cohort study 174 MS patients were enrolled. Among them, 18 patients were anti-HBc + and 19 patients were QuantiFERON®-TB Gold In-Tube (QFT)  +  . No patients with anti-HBc + showed a detectable HBV-DNA and all started DMT. Among QTB + patients, 17 latent TB infections (LTBIs) and 2 active TB infections (TBIs) were identified. After one month of LTBI prophylaxis or TB treatment, respectively, all patients started DMTs.Overall, 149 started DMTs. During DMTs, one ocrelizumab-treated patient with anti-HBc + developed HBV reactivation and six patients (3 on natalizumab, 2 on ocrelizumab and 1 on IFN-β) showed reactivation of HSV-1, with detectable plasma DNA. Finally, 1 cladribine-treated patient experienced VZV reactivation. All the reactivations of latent infections have been successfully treated.

Conclusion

Screening of infectious diseases in DMT candidate MS patients helps to mitigate the infectious risk. During DMTs, a regular assessment of infectious risk allows to avoid discontinuing MS therapy and guarantees a higher degree of safety.

A Retrospective Study on Tuberculous Lymphadenitis: A Finding from Multicenter Referral Hospitals

Background

Extrapulmonary tuberculosis represents about 14% of all cases of tuberculosis (TB) in Malaysia. The aim of the study includes the evaluation of sociodemographic factors, clinical manifestations, comorbidities among patients with tuberculous lymphadenitis and their treatment outcomes.

Methods

The retrospective study was conducted from 2006 to 2008. Data on sociodemographic along with histopathological results were collected. The signs and symptoms were also recorded from TB registers, treatment cards, and TB medical personal files using the standard data collection tool. Among multiple variables, the significant factors identified by univariate analysis were included in the multivariate logistic regression to estimate the odds ratios with the 95% confidence intervals. The statistically significant P value was considered <0.05.

Results

There were 348 (57%) males, and on the other hand, 262 (43%) females which shows almost equal incidence rate of lymphadenitis in both genders. The age group was observed from 2 to 83 years old. Therefore, the age group between 26 and 35 years showed 194 (31.8%) patients diagnosed with lymphadenitis and followed by 16-25 years (21%). The mean age was found as 34.3 ± 14.6 years were majorly reported with positive diagnosis. One hundred and ninety-six (32.1%) Malay population were found with tuberculous lymphadenitis followed by the Chinese population of 148 (24.3%). The other prominent races were Pilipino, Indonesians, and other expatriates. Geographically, patients were from 386 (63.3%) urban population were found positive for lymphadenitis and over 224 (36.7%) population of the rural region. The treatment outcome was observed 444 (72.8%) with successful treatment. The World Health Organization states the types of treatment failures, and accordingly, 85 (13.9%) patients were continued with the therapy that can be due to noncompliance or relapse of TB. Among the unsuccessful outcomes, 194 patients of age group 26-35 years, 65 (33.5%) were reported and 38 (29.7%) patients out of 128 between ages of 16-25 years. Blood test results showed erythrocyte sedimentation rate >10 in 280 (45.9%) patients. Therefore, among 280, there were 115 (41.1%) patients were found to have unsuccessful treatment showing very strong association with P < 0.001.

Conclusion

The finding signifies that effect of weight loss on poor treatment outcomes' and active screening measures for patients with comorbidities are therefore recommended in patients with tuberculous lymphadenitis along with improvements in the diagnosis and early management of comorbidities complications. As young age group was found to have poor or unsuccessful treatment outcomes and required aggressive strategy together with educating patients can further increase the treatment success rate.

A Perspective on the Success and Failure of BCG

TB continues to be one of the major public health threats. BCG is the only available vaccine against TB and confers significant protection against the childhood disease. However, the protective efficacy of BCG against adult pulmonary TB, which represents a larger burden of disease, is highly variable. It has been suggested that prior exposure to environmental mycobacteria (EMb) mitigates the anti-TB efficacy of BCG by blocking its duplication or masking its immunogenicity. However, its effectiveness against childhood TB and failure of repeated administration to provide additional benefit against pulmonary TB, suggest of some other mechanisms for the variable efficacy of BCG against the pulmonary disease. Importantly, TB is a heterogeneous disease occurring in different forms and having distinct mechanisms of pathogenesis. While inability of the immune system to contain the bacilli is responsible for TB pathogenesis in infants, an aggravated immune response to Mtb has been blamed for the development of adult pulmonary TB. Available data suggest that EMb play a key role in heightening the immune response against Mtb. In this article, differential efficacy of BCG against childhood and adult TB is explained by taking into account the heterogeneity of TB, mechanisms of TB pathogenesis, and the effect of EMb on anti-Mtb immunity. It is believed that a refined understanding of the success and failure of BCG will help in the development of effective anti-TB vaccines.

The value of interleukin-27 for differentiating tuberculous pleural effusion from Mycoplasma pneumoniae pneumonic effusion in children

OBJECTIVES

The early diagnosis of tuberculous pleural effusion (TPE) is challenging due to the difficulty of isolating Mycobacterium tuberculosis, and pleural biomarkers are an optional choice. Recent studies showed that interleukin-27 (IL-27) appears to be a new accurate biomarker for TPE in adults and no related studies were reported in children. In this study, we aimed to evaluate the potential value of IL-27 in pediatric tuberculous pleurisy by detecting its levels in pleural fluid and serum.

METHODS

A total of 48 children with TPE and 64 children with severe Mycoplasma pneumoniae (MP) pneumonic effusion (SMPPE) were enrolled in this study. IL-27 concentrations were measured in serum and pleural fluid. The diagnostic yield of IL-27 was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

The level of p-IL-27 in TPE showed statistically no significant difference when compared with SMPPE (p > 0.05). However, pleural fluid IL-27 (p-IL-27) / serum IL-27 (s-IL-27) ratio in TPE were significantly much higher than those in SMPPE (p < 0.05). By the analysis of the ROC curves, the diagnostic sensitivity and specificity of the p-IL-27/s-IL-27 ratio were 100% and 48.44%, respectively (cutoff value of 1.0280). The area under the ROC curve for p-IL-27/s-IL-27 was 0.7295.

CONCLUSION

Pleural fluid IL-27 alone was not accurate in distinguishing pediatric TPE from SMPPE, which was different from the diagnostic value of IL-27 in adult studies due to the different disease spectra between children and adults. Our results implied that the p-IL-27/s-IL-27 ratio had a potential value in distinguishing TPE from SMPPE. However, the specificity of IL-27 was relatively lower and it is necessary to find a more specific marker in tuberculous pleurisy of children.

Impact of Latent Tuberculosis on Severity and Outcomes in Admitted COVID-19 Patients

Background

There is limited data on coronavirus disease 2019 (COVID-19) and latent tuberculosis infection (LTBI).

Methodology

We analyzed data of admitted COVID-19 patients evaluated for LTBI to examine the impact of LTBI on severity, laboratory parameters, and COVID-19 outcome. Prospectively collected data were analyzed for 60 patients who were administered the Mantoux tuberculosis skin test (TST) using five tuberculin units of purified protein derivative. All patients were administered TST irrespective of Bacille Calmette-Guérin (BCG) vaccination status. Comorbidities, clinical features, radiologic involvement, laboratory parameters, and clinical course were analyzed concerning LTBI.

Results

The mean age was 45.9 (±15.2) years, and 35 (58.3%) patients had non-severe disease. The vast majority (n = 56/60; 93.3%) had been vaccinated with single-dose BCG in infancy or early childhood, as per national immunization guidelines. LTBI was diagnosed in 15 (25%) patients. LTBI prevalence was lower in severe (n = 1/25; 4%) than non-severe (n = 14/35; 40%) COVID-19 (p = 0.01) patients. LTBI patients had lower percentage neutrophil count, higher lymphocyte percentage, higher monocyte count, lower neutrophil-lymphocyte (NL) ratio, lower alanine aminotransferase, lower C-reactive protein, and lesser radiologic involvement compared to those without LTBI (p < 0.05). Similarly, among the mild COVID-19 subgroup, those with LTBI had higher lymphocyte and monocyte counts and lesser radiologic involvement than those without LTBI (p < 0.05).

Conclusions

LTBI patients appear to have milder disease, higher lymphocyte and monocyte count, higher NL ratio, and lesser radiographic involvement. This observation needs to be studied in larger studies using interferon release assays.

Subsequent Antituberculous Treatment May Not Be Mandatory Among Surgically Resected Culture-Negative Pulmonary Granulomas: A Retrospective Nationwide Multicenter Cohort Study

Background

Histologic diagnosis of granuloma is often considered clinically equivalent to a definite diagnosis of pulmonary tuberculosis (TB) in endemic areas. Optimal management of surgically resected granulomatous inflammation in lung with negative mycobacterial culture results, however, remains unclear.

Methods

From 7 medical institutions in northern, middle, and southern Taiwan between January 2010 and December 2018, patients whose surgically resected pulmonary nodule(s) had histological features suggestive of TB but negative microbiological study results and who received no subsequent anti-TB treatment were identified retrospectively. All patients were followed up for 2 years until death or active TB disease was diagnosed.

Results

A total of 116 patients were enrolled during the study period. Among them, 61 patients (52.6%) were clinically asymptomatic, and 36 (31.0%) patients were immunocompromised. Solitary pulmonary nodule accounted for 44 (39.6%) of all cases. The lung nodules were removed by wedge resection in 95 (81.9%), lobectomy in 17 (14.7%), and segmentectomy in 4 (3.4%) patients. The most common histological feature was granulomatous inflammation (n=116 [100%]), followed by caseous necrosis (n=39 [33.6%]). During follow-up (218.4 patient-years), none of the patients developed active TB.

Conclusions

In patients with surgically resected culture-negative pulmonary granulomas, the incidence rate of subsequent active TB is low. Watchful monitoring along with regular clinical, radiological, and microbiological follow-up, instead of routine anti-TB treatment, may also be a reasonable option.

Risk assessment of latent tuberculosis infection through a multiplexed cytokine biosensor assay and machine learning feature selection

Accurate detection and risk stratification of latent tuberculosis infection (LTBI) remains a major clinical and public health problem. We hypothesize that multiparameter strategies that probe immune responses to Mycobacterium tuberculosis can provide new diagnostic insights into not only the status of LTBI infection, but also the risk of reactivation. After the initial proof-of-concept study, we developed a 13-plex immunoassay panel to profile cytokine release from peripheral blood mononuclear cells stimulated separately with Mtb-relevant and non-specific antigens to identify putative biomarker signatures. We sequentially enrolled 65 subjects with various risk of TB exposure, including 32 subjects with diagnosis of LTBI. Random Forest feature selection and statistical data reduction methods were applied to determine cytokine levels across different normalized stimulation conditions. Receiver Operator Characteristic (ROC) analysis for full and reduced feature sets revealed differences in biomarkers signatures for LTBI status and reactivation risk designations. The reduced set for increased risk included IP-10, IL-2, IFN-γ, TNF-α, IL-15, IL-17, CCL3, and CCL8 under varying normalized stimulation conditions. ROC curves determined predictive accuracies of > 80% for both LTBI diagnosis and increased risk designations. Our study findings suggest that a multiparameter diagnostic approach to detect normalized cytokine biomarker signatures might improve risk stratification in LTBI.

Challenges in LTBI care in the United States identified using a nationwide TB medical consultation database

BACKGROUND

Identifying and treating individuals with latent TB infection (LTBI) represents a critical and challenging component of national TB elimination. Medical consultations by the Centers for Disease Control and Prevention (CDC) funded TB Centers of Excellence (COEs) are an important resource for healthcare professionals (HCPs) caring for individuals with LTBI. This study aimed to identify the most common clinical concerns regarding LTBI care and to describe epidemiologic and clinical features of patients discussed in these consultations.

METHODS

This mixed-methods study randomly sampled 125 consultation inquiries related to LTBI from the COEs' medical consultation database in 2018. Text from consultation records were reviewed and coded to identify reasons for the inquiries and common epidemiologic and clinical patient characteristics.

RESULTS

The most common topics of inquiry for consultation included accurate LTBI diagnosis (36%), management of LTBI treatment-related issues (22%), and choice of appropriate LTBI treatment regimen (17%). Patients for whom consultations were requested commonly had another medical condition (34%), were non-U.S. born (31%), were children (25%), and had a history of travel to TB-endemic areas (18%).

CONCLUSION

Our findings emphasize the challenge of managing patients with either suspected or confirmed LTBI, highlighting the need for ongoing medical consultation support for nuanced clinical and epidemiologic scenarios.

The knowns and unknowns of latent Mycobacterium tuberculosis infection

Humans have been infected with Mycobacterium tuberculosis (Mtb) for thousands of years. While tuberculosis (TB), one of the deadliest infectious diseases, is caused by uncontrolled Mtb infection, over 90% of presumed infected individuals remain asymptomatic and contain Mtb in a latent TB infection (LTBI) without ever developing disease, and some may clear the infection. A small number of heavily Mtb-exposed individuals appear to resist developing traditional LTBI. Because Mtb has mechanisms for intracellular survival and immune evasion, successful control involves all of the arms of the immune system. Here, we focus on immune responses to Mtb in humans and nonhuman primates and discuss new concepts and outline major knowledge gaps in our understanding of LTBI, ranging from the earliest events of exposure and infection to success or failure of Mtb control.

Alveolar macrophages from persons living with HIV show impaired epigenetic response to Mycobacterium tuberculosis

Persons living with HIV (PLWH) are at increased risk of tuberculosis (TB). HIV-associated TB is often the result of recent infection with Mycobacterium tuberculosis (Mtb) followed by rapid progression to disease. Alveolar macrophages (AM) are the first cells of the innate immune system that engage Mtb, but how HIV and antiretroviral therapy (ART) impact on the anti-mycobacterial response of AM is not known. To investigate the impact of HIV and ART on the transcriptomic and epigenetic response of AM to Mtb, we obtained AM by bronchoalveolar lavage from 20 PLWH receiving ART, 16 control subjects who were HIV-free (HC), and 14 subjects who received ART as pre-exposure prophylaxis (PrEP) to prevent HIV infection. Following in-vitro challenge with Mtb, AM from each group displayed overlapping but distinct profiles of significantly up- and down-regulated genes in response to Mtb. Comparatively, AM isolated from both PLWH and PrEP subjects presented a substantially weaker transcriptional response. In addition, AM from HC subjects challenged with Mtb responded with pronounced chromatin accessibility changes while AM obtained from PLWH and PrEP subjects displayed no significant changes in their chromatin state. Collectively, these results revealed a stronger adverse effect of ART than HIV on the epigenetic landscape and transcriptional responsiveness of AM.

Biologics for the Management of Inflammatory Bowel Disease: A Review in Tuberculosis-Endemic Countries

The advent of biologics and biologic therapy has transformed the management of inflammatory bowel disease (IBD) with enhanced early and adequate responses to treatment, fewer hospitalizations, a reduced need for surgery, and unprecedented outcomes including complete mucosal and histologic healing. However, an important issue with the use of anti-tumor necrosis factor (anti-TNF) agents in IBD is the increased risk of tuberculosis (TB). This is compounded by the diagnostic dilemma when differentiating between Crohn’s disease and gastrointestinal TB, and the potentially serious consequences of initiating an incorrect treatment in the case of misdiagnosis. The interplay between IBD and TB is most relevant in Asia, where more than 60% of the 10.4 million new TB cases in 2016 were reported. A number of studies have reported an increased risk of TB with anti-TNF agents, including in patients who had tested negative for TB prior to treatment initiation. The limited evidence currently available regarding adhesion molecule antagonists such as vedolizumab suggests a comparatively lower risk of TB, thus making them a promising option for IBD management in TB-endemic regions. This comprehensive review examines the available literature on the risk of TB with the use of biologics in the TB-endemic regions of Asia, focusing on the diagnostic dilemma, the risk of reactivation, and the optimized management algorithms for latent and active disease.

Mycobacterium tuberculosis in solid organ transplant donors and recipients

PURPOSE OF REVIEW

Due to impaired immune response, solid organ transplant (SOT) recipients are susceptible to tuberculosis (TB) and its subsequent morbidity and mortality. Current prevention strategies, diagnostic and treatment approach to TB infection in donors and recipients were reviewed in this article.

RECENT FINDINGS

Screening of latent tuberculosis infection (LTBI) in donors and recipients is the cornerstone of TB-preventive strategy in recipients and requires an assessment of TB risk factors, TB-specific immunity testing, and radiographic evaluation. Interferon-gamma release assay has superseded the tuberculin skin test in LTBI evaluation despite its recognized limitations. LTBI treatment should be offered to transplant candidates and living donors before transplantation and donation, respectively. Diagnosis of TB disease can be challenging because of nonspecific clinical presentation in the recipient and is limited by the sensitivity of current diagnostics. The approach to LTBI and TB disease treatment is similar to the general population, but can be challenging because of potential drug interactions and toxicities.

SUMMARY

The appropriate evaluation of donors and recipients for TB can mitigate posttransplant TB disease. Current approaches to diagnosis and treatment parallels that of immunocompetent hosts. Future research evaluating existing and novel diagnostics and treatment in transplant recipients is needed.

Species-Specific Interferon-Gamma Release Assay for the Diagnosis of Mycobacterium abscessus Complex Infection

Mycobacterium abscessus complex (MABC) infection has a devastating impact on the course of cystic fibrosis (CF) and non-CF lung disease. Diagnosis of MABC pulmonary disease is challenging, and current diagnostic approaches lack accuracy, especially in CF. In this study, we aimed to establish an MABC-specific interferon-γ release assay to detect host immune responses to MABC and improve diagnostics of MABC infection by the detection of antigen-specific T cells. Four species-specific proteins of MABC were overexpressed in an Escherichia coli expression system. Purified proteins were used to stimulate peripheral blood mononuclear cells of study subjects in an ELISpot assay. Interferon-γ response of 12 subjects with established diagnosis of MABC infection (10 CF and two non-CF) was compared with 35 controls (22 CF and 13 non-CF) distributed to three control groups, 17 CF subjects without NTM infection, nine subjects with NTM infection other than MABC, and nine subjects with tuberculosis. Cellular in vitro responses in the MABC group were stronger than in the control groups, especially toward the protein MAB_0405c (39 vs. 4 spots per 300,000 PBMC, p = 0.004; data represent mean values) in all patients and also in the subgroup of CF subjects (39 spots vs. 1 spot, p = 0.003). Receiver operating characteristic curve analysis indicated that spot numbers of at least 20 were highly predictive of MABC infection (all patients: area under curve 0.773, sensitivity 58%, and specificity 94%; CF patients: area under curve 0.818, sensitivity 60%, and specificity 100%). In conclusion, we identified MAB_0405c as a protein that may stimulate MABC-specific interferon-γ secretion and may add to the diagnosis of MABC infection in affected patients.

Prevalence of latent tuberculosis before biotherapy initiation in rheumatoid arthritis and spondyloarthritis: data from the Moroccan biotherapy registry

Before the initiation of biotherapy in the treatment of rheumatic diseases, it is highly recommended for the patients to be screened for latent tuberculosis infection (LTBI). The objective of this study is to identify the prevalence of LTBI among patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) before the initiation of biologic therapy in the Moroccan biotherapy registry (RBSMR). A cross sectional study was conducted using the baseline data of the Moroccan biotherapy registry. Tuberculin skin test or IGRA test or both tests were done before starting anti-TNF treatment for screening LTBI. The comparisons between positive and negative LTBI patients according to rheumatic disease were examined using categorical comparisons. 259 patients were included in this study.94 patients had RA and 165 had SpA. The mean age of the RA patients was 50.49 ± 11.82 years with a majority of females (84%). The mean age for the SpA patients was 36 ± 13.7 years with a majority of males (67.3%). The prevalence of LTBI in the RBSMR was 21.6%. This prevalence was at 24.8% in SpA patients, while it was at 15.9% for RA patients. After the comparison between positive and negative LTBI patients according to rheumatic disease, no demographic, clinical, or therapeutic characteristics were statistically associated with LTBI. This study found that in an endemic TB country like Morocco, a high prevalence of patients with SpA and RA had LTBI, and that RA patients had a lower prevalence than SpA patients.

Comparing the cost-effectiveness of two screening strategies for latent tuberculosis infection in Portugal

INTRODUCTION AND OBJECTIVES

Screening for latent tuberculosis infection (LTBI) in close contacts of infectious TB cases might include Tuberculin Skin Test (TST) and Interferon-Gamma Release Assays (IGRA), in combination or as single-tests. In Portugal, the screening strategy changed from TST followed by IGRA to IGRA-only testing in 2016. Our objective was to compare the cost-effectiveness of two-step TST/IGRA with the current IGRA-only screening strategy in immunocompetent individuals exposed to individuals with respiratory TB.

MATERIALS AND METHODS

We reviewed clinical records of individuals exposed to infectious TB cases diagnosed in 2015 and 2016, in two TB outpatient centers in the district of Porto. We estimated medical, non-medical and indirect costs for each screening strategy, taking into account costs of tests and health care personnel, travel distance from place of residence to screening site and employment status. We calculated the incremental cost-effectiveness ratio (ICER) as the cost difference between the two screening strategies with the difference number of LTBI diagnosis as a measure of cost-effectiveness, assuming that treating LTBI is a cost-effective intervention. We also calculated adjusted odds-ratios to test the association between diagnosis of LTBI and screening strategy and estimated the total cost for averting a potential TB case.

RESULTS

We compared 499 contacts TST/IGRA screened with 547 IGRA-only. IGRA-only strategy yielded a higher screening effectiveness for diagnosing latent tuberculosis infection (aOR 2.12, 95%CI: 1.53 - 2.94). ICER was €106 per LTBI diagnosis, representing increased effectiveness with a slightly increased cost of IGRA-only screening strategy.

CONCLUSIONS

Our data suggests that in Portugal LTBI screening with IGRA-only is more cost-effective than the two-step TST/IGRA testing strategy, preventing a higher number of cases of TB cases.

Latent tuberculosis screening before kidney transplantation in the South of Brazil

Background:

Tuberculosis (TB) is a prevalent infection after kidney transplantation (KT) in high-burden countries. Latent tuberculosis infection (LTBI) screening includes previous TB history, chest radiograph findings, and tuberculin test (TST) and/or interferon-gamma release assays (IGRAs) results. We aimed to compare our routine LTBI screening of KT candidates and living donors (LD) with their IGRA results, and evaluate if this would improve isoniazid (INH) treatment referral.

Methods:

We evaluated adult KT candidates and LD with complete routine LTBI screening and QuantiFERON-TB® Gold In-Tube (QFT) testing. Blood samples were collected from April 4th, 2014 to October 31st, 2018, with follow-up until October 31st, 2019.

Results:

There were 116 KT recipients, with 30% QFT-positive results. Positive QFT was associated with past TB history (p=0.007), positive TST (p<0.0001), residual radiographic lesions (p=0.003), and diabetes (p=0.035). There were 25 LD, 40% had positive QFT. Positive QFT was associated with a positive TST (p=0.002). Positive QFT results increased INH referral in 80%. Post-transplant TB incidence was 2.6% in a median follow-up of 2 (1-33) months. No variables were associated with post-transplant TB. TB patients had inferior, although non-significant, 5-year graft survival (66.7% vs. 76.5%) (p = 0.402).

Conclusion:

In the present study, the association of QFT to our routine LTBI screening incremented INH treatment referral, but there was still a high incidence of post-transplant TB, possibly related to other forms of infection, such as new exposure and donor transmission.