The definition of tuberculosis infection based on the spectrum of tuberculosis disease

Exploring the multifaceted roles of resuscitation-promoting factors in tuberculosis: Implications for diagnosis, vaccine development, and drug targeting

Tuberculosis (TB) remains a significant global health challenge, necessitating continued research efforts to unravel its complex pathogenesis and advance diagnostic, therapeutic, and preventive strategies. Resuscitation-promoting factors (Rpfs) are peptidoglycan-hydrolyzing enzymes that have gained attention due to their key roles in TB infection dynamics. This review aims to provide a comprehensive overview of Rpfs in TB, highlighting their immunological roles, diagnostic potential, and implications for vaccine development and drug targeting through both in silico and experimental approaches. Rpfs exhibit diverse roles in TB, influencing bacterial resuscitation from dormancy, and immune modulation through interactions with host immune cells, such as dendritic cells, and they are potential targets for novel diagnostic and therapeutic interventions. Their ability to stimulate immune responses, particularly interferon-γ production by T cells, underscores their potential as vaccine candidates against TB. Moreover, Rpfs represent promising targets for drug discovery, with inhibitors potentially disrupting bacterial resuscitation and growth.

Multiplexed cytokine profiling identifies diagnostic signatures for latent tuberculosis and reactivation risk stratification

Active tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) bacteria and is characterized by multiple phases of infection, leading to difficulty in diagnosing and treating infected individuals. Patients with latent tuberculosis infection (LTBI) can reactivate to the active phase of infection following perturbation of the dynamic bacterial and immunological equilibrium, which can potentially lead to further Mtb transmission. However, current diagnostics often lack specificity for LTBI and do not inform on TB reactivation risk. We hypothesized that immune profiling readily available QuantiFERON-TB Gold Plus (QFT) plasma supernatant samples could improve LTBI diagnostics and infer risk of TB reactivation. We applied a whispering gallery mode, silicon photonic microring resonator biosensor platform to simultaneously quantify thirteen host proteins in QFT-stimulated plasma samples. Using machine learning algorithms, the biomarker concentrations were used to classify patients into relevant clinical bins for LTBI diagnosis or TB reactivation risk based on clinical evaluation at the time of sample collection. We report accuracies of over 90% for stratifying LTBI + from LTBI- patients and accuracies reaching over 80% for classifying LTBI + patients as being at high or low risk of reactivation. Our results suggest a strong reliance on a subset of biomarkers from the multiplexed assay, specifically IP-10 for LTBI classification and IL-10 and IL-2 for TB reactivation risk assessment. Taken together, this work introduces a 45-minute, multiplexed biomarker assay into the current TB diagnostic workflow and provides a single method capable of classifying patients by LTBI status and TB reactivation risk, which has the potential to improve diagnostic evaluations, personalize treatment and management plans, and optimize targeted preventive strategies in Mtb infections.

Macrophage Differentiation and Metabolic Adaptation in Mycobacterial Infections

The adaptation of macrophages-the most common tissue-resident immune cells-to metabolic and microbial cues with high local variability is essential for the maintenance of organ integrity. In homeostasis, macrophages show largely predictable tissue-specific differentiation, as recently revealed by multidimensional methods. However, chronic infections with human-adapted pathogens substantially contribute to the differentiation complexity of tissue macrophages, which has been only partially resolved. Specifically, the response to mycobacterial species-which range from Mycobacterium tuberculosis (with highest specificity for humans, broad organ tropism, yet tissue-specific disease phenotypes) to environmental mycobacteria with humans as accidental hosts-may serve as a paradigm of tissue macrophage adaptation mechanisms. While mycobacterial species-specific tissue preferences are partially related to the mode of acquisition and pathogen characteristics, evolutionary convergence with macrophages driven by metabolic features of the target organ likely contributes to infection resistance and immunopathology. In this review, we unravel the mechanisms of tissue-specific macrophage differentiation and its limitations in mycobacterial infections.

The Role and Potential Application of IL-12 in the Immune Regulation of Tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, affecting millions annually and leading to substantial mortality, particularly in developing countries. The pathogen's ability to persist latently and evade host immunity, combined with the emergence of drug-resistant strains, underscores the need for innovative therapeutic strategies. This review highlights the crucial role of interleukin-12 (IL-12) in coordinating immune responses against TB, focusing on its potential as an immunotherapy target. IL-12, a key Th1 cytokine, enhances cellular immunity by promoting Th1 cell differentiation and IFN-γ production, vital for Mtb clearance. By stimulating cytotoxic T lymphocytes and establishing immune memory, IL-12 supports robust host defense mechanisms. However, the complexity of IL-12 biology, including its roles in pro-inflammatory and regulatory pathways, necessitates a nuanced understanding for effective therapeutic use. Recent studies have shown how IL-12 impacts T cell synapse formation, exosome-mediated bystander activation, and interactions with other cytokines in shaping T cell memory. Genetic defects in the IL-12/IFN-γ axis link to susceptibility to mycobacterial diseases, highlighting its importance in TB immunity. The review also addresses challenges like cytokine imbalances seen in TNF-α/IFN-γ synergy, which exacerbate inflammation, and the implications for IL-12-based interventions. Research into modulating IL-12, including its use as an adjuvant and in recombinant vaccines, promises improved TB treatment outcomes and vaccine efficacy. The review concludes by stressing the need for continued investigation into IL-12's molecular mechanisms towards precision immunotherapies to combat TB and its complications.

Does perceived social support buffer the impact of psychological distress on health-related quality of life among people living with tuberculosis?

People living with tuberculosis have been reported to encounter greater distress than normal population, and this distress is known to impact their quality of life adversely. However, studies examining the mechanisms that could mitigate this adverse impact of distress are sparse, hence this study. We investigated whether perceived social support (including emotional and instrumental support from family, friends, and significant others) plays a buffering role in the link between psychological distress and health-related quality of life (HRQoL) among people living with tuberculosis (PLWTB). We utilized a cross-sectional design to conveniently sample 200 tuberculosis patients drawn from a health facility in South-Eastern Nigeria. These participants completed measures of relevant variables. Results showed that psychological distress was negatively associated with HRQoL. Perceived social support (from family, friends, and significant others) significantly predicted HRQoL. Perceived social support moderated the link between psychological distress and HRQoL, but did not buffer against the association. Management of psychological distress associated with tuberculosis health condition should therefore be a major focus in efforts to improve the health and well-being of TB patients.

Management of tuberculosis risk, screening and preventive therapy in patients with chronic autoimmune arthritis undergoing biotechnological and targeted immunosuppressive agents

Tuberculosis (TB) is the leading cause of death in the world from an infectious disease. Its etiologic agent, the Mycobacterium tuberculosis (Mtb), is a slow-growing bacterium that has coexisted in humans for thousands of years. According to the World Health Organization, 10.6 million new cases of TB and over 1 million deaths were reported in 2022. It is widely recognized that patients affected by chronic autoimmune arthritis such as rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) have an increased incidence rate of TB disease compared to the general population. As conceivable, the risk is associated with age ≥65 years and is higher in endemic regions, but immunosuppressive therapy plays a pivotal role. Several systematic reviews have analysed the impact of anti-TNF-α agents on the risk of TB in patients with chronic autoimmune arthritis, as well as for other biologic disease-modifying immunosuppressive anti-rheumatic drugs (bDMARDs) such as rituximab, abatacept, tocilizumab, ustekinumab, and secukinumab. However, the data are less robust compared to those available with TNF-α inhibitors. Conversely, data on anti-IL23 agents and JAK inhibitors (JAK-i), which have been more recently introduced for the treatment of RA and PsA/AS, are limited. TB screening and preventive therapy are recommended in Mtb-infected patients undergoing bDMARDs and targeted synthetic (ts)DMARDs. In this review, we evaluate the current evidence from randomized clinical trials, long-term extension studies, and real-life studies regarding the risk of TB in patients with RA, PsA, and AS treated with bDMARDs and tsDMARDs. According to the current evidence, TNF-α inhibitors carry the greatest risk of TB progression among bDMARDs and tsDMARDs, such as JAK inhibitors and anti-IL-6R agents. The management of TB screening and the updated preventive therapy are reported.

Incipient and subclinical tuberculosis: a narrative review

Mycobacterium tuberculosis has been known to infect humans for eons. It is an airborne infectious disease transmitted through droplet nuclei of 1 to 5 µm in diameter. Historically, tuberculosis (TB) was considered a distinct condition characterized by TB infection and active TB disease. However, recently, the concept of a dynamic spectrum of infection has emerged, wherein the pathogen is initially eradicated by the innate or adaptive immune system, either in conjunction with or independently of T cell priming. Other categories within this spectrum include TB infection, incipient TB, subclinical TB, and active TB disease. Various host- and pathogen-related factors influence these categories. Furthermore, subclinical TB can facilitate the spread of infection within the community. Due to its asymptomatic nature, there is a risk of delayed diagnosis, and some patients may remain undiagnosed. Individuals with subclinical TB may stay in this stage for an indeterminate period without progressing to active TB disease, and some may even experience regression. Early diagnosis and treatment of TB are essential to meet the 2035 targets outlined in the end-TB strategy. This strategy should also include incipient and subclinical TB. This review will focus on the definition, natural history, burden, trajectory, transmissibility, detection, and management of early-stage TB.

Ocular Tuberculosis Diagnosis Through Biomarkers: Clinical Relevance of Serum C1q and Whole Blood Interferon Gene Signature Score

PURPOSE

To assess the clinical relevance of pathophysiology-based biomarkers, specifically serum C1q and whole blood interferon gene signature score (IGSS), in ocular tuberculosis (OTB) diagnosis by conducting an integrative analysis of clinical presentations and treatment response.

METHODS

This retrospective cohort study analysed data from 70 patients with suspected OTB at a tertiary care uveitis practice in Indonesia. Serum C1q levels and whole blood IGSS were quantified. Patients were categorized into four quadrants based on their biomarker profiles: quadrant 1 (high C1q & low IGSS), quadrant 2 (high C1q & high IGSS), quadrant 3 (low C1q & high IGSS), and quadrant 4 (low C1q & low IGSS). Characteristics of clinical presentations, work-up results, and treatment outcomes were explored according to the predefined quadrants.

RESULTS

We identified that the majority of OTB patients diagnosed with concurrent active pulmonary TB were in quadrant 1, 2, or 3 (20/23, 87.0%). Twenty-seven patients (27/47, 57.4%) with clinically undifferentiated uveitis were in quadrant 4 (p < 0.001). Among patients in quadrants 1, 2, and 3, completion of a full course of antitubercular treatment (ATT) was associated with a lower number of patients showing persistence or recurrence of ocular inflammation compared to those who were not fully treated with ATT (14.3% vs 85.7%, p = 0.001).

CONCLUSIONS

Based on the analysis of clinical features and treatment outcomes, patients with elevated levels of either or both serum C1q and whole blood IGSS may reflect active TB disease in the eye, necessitating full ATT management.

Methods and Models for Studying Mycobacterium tuberculosis in Respiratory Infections

Respiratory infections, including tuberculosis, constitute a major global health challenge. Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the leading causes of mortality worldwide. The disease's complexity is attributed to Mtb's capacity to persist in latent states, evade host immune defenses, and develop resistance to antimicrobial treatments, posing significant challenges for diagnosis and therapy. Traditional models, such as animal studies and two-dimensional (2D) in vitro systems, often fail to accurately recapitulate human-specific immune processes, particularly the formation of granulomas-a defining feature of tubercular infection. These limitations underscore the need for more physiologically relevant models to study TB pathogenesis. Emerging three-dimensional (3D) in vitro systems, including organoids and lung-on-chip platforms, offer innovative approaches to mimic the structural and functional complexity of the human lung. These models enable the recreation of key aspects of the tubercular granulomas, such as cellular interactions, oxygen gradients, and nutrient limitations, thereby providing deeper insights into Mtb pathogenesis. This review aims to elucidate the advantages of 3D in vitro systems in bridging the translational gap between traditional experimental approaches and clinical applications. Particular emphasis is placed on their potential to address challenges related to genetic variability in both the host and pathogen, thereby advancing tubercular research and therapeutic development.

Whole Blood vs Serum-Derived Exosomes for Host and Pathogen-Specific Tuberculosis Biomarker Identification: RNA-Seq-Based Machine-Learning Approach

Mycobacterium tuberculosis (Mtb) remains a leading infectious disease responsible for millions of deaths. RNA sequencing is a rapidly growing technique and a powerful approach to understanding host and pathogen cross-talks via transcriptional responses. However, its application is limited due to the high costs involved.This study is a preliminary attempt to understand host-pathogen cross-talk during TB infection in different TB clinical cohorts using two biological fluids: Whole blood and serum exosomes (EXO). We conducted an RNA-sequencing machine-learning approach using 20 active TB (ATB), 11 latent TB (LTB), three healthy control (HC) whole blood datasets, and two ATB, LTB, and HC serum EXO datasets. During the study, host-derived differentially expressed genes (DEGs) were identified in both whole blood and EXOs, while EXOs were successful in identifying pathogen-derived DEGs only in LTB. The majority of the DEGs in whole blood were up-regulated between ATB and HC, and ATB and LTB, while down-regulated between LTB and HC, which was vice versa for the EXOs, indicating different mechanisms in response to different states of TB infection across the two different biological samples. The pathway analysis revealed that whole blood gene signatures were mainly involved in host immune responses, whereas exosomal gene signatures were involved in manipulating the host's cellular responses and supporting Mtb survival. Overall, identifying both host and pathogen-derived gene signatures in different biological samples for intracellular pathogens like Mtb is vital to decipher the complex interplay between the host and the pathogen, ultimately leading to more successful future interventions.

Clinical features of Tibetan adolescent tuberculosis at high altitudes: a retrospective study

BACKGROUND

Adolescent pulmonary tuberculosis (TB) is considered inadequately recognized and underreported at high altitudes. This study aimed to investigate the clinical features of adolescent pulmonary TB patients at high altitudes in China.

METHOD

A retrospective analysis was performed at Linzhi People's Hospital. Patients recruited were newly diagnosed with pulmonary TB. Detailed information, including demographics, medical history, presenting symptoms, laboratory results and pulmonary images, was collected. Sputum samples were collected to detect Mycobacterium tuberculosis via the GeneXpert MTB/RIF assay.

RESULT

A total of 63 adolescents and 192 adults were recruited. Compared with those in the adult group, typical TB-related manifestations were significantly less common in the adolescent group (all P < 0.05). The adolescent group had significantly more subclinical TB (23.8% vs. 8.3%, P = 0.001) and a higher previous tuberculosis exposure rate (38.8% vs. 8.3%, P < 0.001) than did the adult group. The erythrocyte sedimentation rate was significantly higher in the adolescent group than in the adult group (P = 0.026). Compared with adult patients, adolescent patients presented a lower rate of pleural thickening (P < 0.01). Compared with active adolescent patients, there were more female than male in the adolescent subclinical TB group (12/15 vs 27/48) and the positive rate of the sputum GeneXpert test was higher in subclinical TB group (6/15 vs 8/48).

CONCLUSION

Adolescent patients with pulmonary TB at high altitudes were prone to subclinical TB and have a higher previous TB exposure rate. Sputum GeneXpert test and ESR were important for the diagnosis of subclinical pulmonary TB.

Investigation of the prevalence of latent tuberculosis in cancer patients compared to non-cancer patients: a case-control study

Background

Latent tuberculosis (TB) can reactivate in immunocompromised individuals, such as cancer patients undergoing chemotherapy, leading to severe complications. Understanding the prevalence of latent TB in this high-risk group is crucial, especially in regions with moderate to high TB burdens.

Aim

This study aims to determine the prevalence of latent tuberculosis in cancer patients before chemotherapy and immunotherapy to guide preventive interventions and reduce the risk of TB reactivation.

Methods

This case-control study was conducted at Sina Hospital in Tehran, Iran, from 2012 to 2022. A total of 392, including 107 newly diagnosed cancer (case) and 285 non-cancer (control) patients, were enrolled in this study. All patients had received the Bacillus Calmette-Guérin (BCG) vaccine at the age of one. They underwent a thorough clinical examination and were screened using the tuberculin skin test (TST) to detect latent TB. Any active TB cases were identified through acid-fast smear tests. The data collected from the study participants was then analyzed.

Results

The results showed no significant difference in the size of TST between cancer and non-cancer patients (cases: median = 2 mm, IQR: 1-12; controls: median = 2 mm, IQR: 1-5; p = 0.09). The prevalence of latent TB was 27.1% in cancer patients and 20.7% in non-cancer patients, with no significant association identified between latent TB and malignancies (P-value = 0.176). Over a median follow-up of 4 years, mortality was significantly higher in cancer patients compared to controls (42.1% vs 1.8%; P< 0.001, OR = 40.64). Additionally, deceased patients exhibited a greater prevalence of latent TB (44% vs 19.3% in survivors; P< 0.001, OR = 3.28), and increased size of TST was associated with higher mortality risk among cancer patients.

Conclusion

In conclusion, this study emphasizes the need for vigilant latent TB screening in cancer patients, given the association between larger TST sizes and increased mortality risk. While no direct link between cancer type and latent TB was found, proactive TB management remains crucial, particularly for those undergoing immunosuppressive therapy.

Tuberculosis and T cells: Impact of T cell diversity in tuberculosis infection

Tuberculosis is a global threat and is still a leading cause of death due to an infectious agent. The infection is spread through inhalation of M. tb containing aerosol droplets. Bacteria after reaching the lung alveoli are engulfed by alveolar macrophages, leading to an immune response. Then, pro-inflammatory cytokines are released by these macrophages, recruiting other antigen-presenting cells like dendritic cells. These cells phagocytose the bacteria and present mycobacterial antigens to naïve T cells. After activation by DCs, T cells differentiate into various T cells subsets, viz. CD4+, CD8+, Th17, Treg, Tfh cells and others display enormous diversification in their characteristics and functions. This review comprises a comprehensive literature on conventional and unconventional T cells, highlighting the polyfunctional T cells as well, their role in controlling TB infection, and their implications in the spectrum of TB infection. While some subsets such as CD4+ T cells are extensively studied, some T cell subsets such as gamma delta T cells and Tfh cells remain poorly understood in the pathophysiology of tuberculosis, despite having significant potential implications. The goal of TB eradication can be assisted by development of better vaccines against TB, which can effectively induce a robust and long-term T cells memory. The same has been discussed in the latter part of this review. BCG being the standalone commercialised TB vaccine so far has its limitations. Strategies for the enhancement of BCG along with novel studies in vaccine development, has also been discussed in great detail. Lastly, T cells display a complex interplay of an adaptive immune response against TB, with activation and enhancement of the innate immune responses. Therefore, it is critical to fully understand the role of various T cells subsets in pathophysiology of tuberculosis to provide better therapeutic inventions and improve patient care.

Risk of tuberculosis disease in patients receiving TNF-α antagonist therapy: A meta-analysis of randomized controlled trials

Introduction

Tuberculosis (TB) risk associated with tumor necrosis factor-alpha (TNF-α) antagonist therapy in patients with autoimmune diseases is a significant concern. This study aims to evaluate the risk of TB disease associated with TNF-α antagonist therapy.

Methods

An extensive search of PubMed/MEDLINE, EMBASE, and the Cochrane CENTRAL databases was conducted to identify randomized controlled trials (RCTs) assessing TB disease risk in patients receiving TNF-α antagonist therapy available until November 1, 2024. The pooled statistic used was the weighted odds ratio (OR) and a corresponding 95 % confidence interval (CI). Statistical analysis was performed using Comprehensive Meta-Analysis software, version 3.0 (Biostat Inc., Englewood, NJ, USA).

Results

Fifty-six RCTs, totaling 22,212 adult patients, met the specified eligibility criteria. Pooled analysis revealed an increased risk of TB disease associated with TNF-α antagonist therapy (OR 1.52, 95 % CI 1.03-2.26, p = 0.03). Subgroup analyses indicated a higher risk in patients with rheumatoid arthritis (RA) (OR 2.25, 95 % CI 1.13-4.45, p = 0.02), while no significant associations were found in patients with ankylosing spondylitis (AS) or psoriasis (Ps). Analyses by specific TNF-α antagonist drugs did not yield significant associations with risk of TB disease.

Conclusion

Our study highlights an increased risk of TB disease associated with TNF-α antagonist therapy, particularly in patients with RA. However, the absence of significant associations in AS or Ps patients suggests disease-specific variations in risk of TB disease. Further research is needed to elucidate the long-term safety profile of TNF-α antagonist drugs and their associations with risk of TB disease in different patient populations.

Relevance of antigen-induced IL-6 and mitogen-induced or spontaneous IFN-γ secretions in whole blood cultures for detection of Mycobacterium tuberculosis infection and disease

For an effective control of tuberculosis (TB), there is a persistent need for biomarkers that can report true estimates of TB infection (TBI) and predict its progression towards active TB disease. We investigated whether the cell-mediated immune responses to Mycobacterium tuberculosis (Mtb) antigens could provide such biomarkers. The study subjects (n = 174) comprised a cohort of smear-positive, drug-sensitive, HIV-negative pulmonary TB patients (n = 54) and their household contacts (HC, n = 120). Whole blood cultures, in the presence or absence of Mtb antigens- membrane (MtM), purified protein derivative (PPD) and alpha-crystallin (Acr), or the mitogen PHA were subjected to determinations, by flow cytometry, for T cell proliferative and, by ELISA, for IFN-γ, TNF-α, and IL-6 cytokine responses. Additionally, serum levels of the three cytokines were also estimated. The strongest cell-proliferative and cytokine responses were induced by MtM and IL-6 was the most abundantly produced cytokine. While none of the responses induced by Mtb antigens or the serum cytokines levels could discriminate between TB and HC, the ex vivo cytokine responses induced by PHA or 'spontaneously' could apparently do so. The concentrations of IFN-γ induced by PHA in TB blood cultures were significantly lower than in HC cultures (AUC = 0.72). Conversely, the spontaneous IFN-γ or TNF-α secretions in TB cultures were significantly higher than in HC cultures (AUC = 0.66). Our results suggest that IL-6 responses to MtM could be a sensitive indicator of TBI, and low levels of PHA-induced or high levels of spontaneous IFN-γ secretions in HC blood cultures may indicate a progressive infection.

Vitamin D Receptor Gene Polymorphisms Differentiated Between Tuberculosis Disease and Infection: Causal Association Study

Purpose

Latent tuberculosis infection (LTBI) is a critical stage in tuberculosis (TB)control, and few studies have addressed the role of vitamin D receptor(VDR) gene polymorphisms in differentiating between TB and late-onset TB from an immunogenetic perspective.

Patients and Methods

Recruitment of tuberculosis patients and latently infected population in Urumqi, Xinjiang, and use of propensity score matching(PSM) to match the two groups and control confounding to further construct a Bayesian network to analyze causal associations between VDR polymorphisms and tuberculosis disease status.

Results

137 LTBI and 237 TB were obtained through PSM. Logistic regression showed that the VDR gene BsmI locus, TaqI locus, and ApaI locus were associated with a higher risk of TB in a codominant model (P<0.05). Further Bayesian network construction showed that occupation and being a VDR gene BsmI locus were direct influences on TB disease status, and the VDR gene TaqI locus played an indirect role through the BsmI locus, and the probability of TB risk was highest in individuals with manual labour and BsmI locus of the C/T type, which was 84.15%.

Conclusion

Bayesian network modelling intuitively revealed that individuals with a C/T type of BsmI locus and physical labour are at high risk of TB compared with TB infection, and they are key factors between with TB disease, providing reference evidence for controlling TB progression.

Expert views on screening for tuberculosis infection in patients commencing treatment with a biologic agent

OBJECTIVE

Many biologic agents cause some degree of immunosuppression, which can increase the risk of reactivation of tuberculosis infection (TBI). This risk is variable between individual biologics. We aimed to assess current (and recommended) clinical practice of TBI screening and treatment among patients initiating treatment with biologic agents.

METHODS

An online questionnaire was distributed via email to members of the Global Tuberculosis Network and associated professional organisations to seek insights into the screening for and treatment of TBI in patients treated with biologics.

RESULTS

A total of 163 respondents in 27 countries answered at least one question. For all biologics described in the questionnaire, respondents advised increasing screening relative to current practice. Observed and supported TBI screening rates in patients treated with TNF-a inhibitors were high, especially for older TNF-a inhibitors. Most participants supported TBI screening in patients treated with B- or T-cell inhibitors but not in those treated with interleukin inhibitors. Guideline awareness was higher for TNF-a inhibitors than for other biologic classes (79% vs. 34%).

CONCLUSIONS

Although respondents stated that TBI screening rates are lower than what they consider ideal, there was a tendency to recommend TBI screening in patients treated with biologics not known to be associated with an increased risk of TBI. As a result, there is a potential risk of over-screening and over-treatment of TBI, potentially causing harm, in patients treated with biologics other than TNF-a inhibitors. There is a need to research the risk of TBI associated with biologics and for guidelines to address the spectrum of TBI risk across all types of biologics.

Ocular tuberculosis associated with Epstein-Barr virus myelitis: A case report

Ocular tuberculosis (OTB) is a chronic eye infection caused by Mycobacterium tuberculosis. Some cases of myelitis are associated with Epstein-Barr virus (EBV), with 1-5% of EBV infections leading to neurologic complications. We describe a 34-year-old Iranian woman with OTB and EBV coinfection. Despite initial success with anti-TB agents, the disease progressed, necessitating enucleation. Mycobacterium tuberculosis was detected by a tuberculin coagulation test, and EBV was confirmed via polymerase chain reaction. MRI showed plaques in the spinal cord and brain. The patient was treated with anti-TB and antiretroviral agents. Recognizing TB in the differential diagnosis of EBV myelitis is crucial.

Nano-Medicine for Treatment of Tuberculosis, Promising Approaches Against Antimicrobial Resistance

Even though the number of effective anti-tuberculosis or anti-mycobacterial agents is increasing, a large number of patients experience severe side effects as a result of these drugs. This hurts the patients' well-being and quality of life. Tumor cells that survive treatment modalities can become chemotherapy resistant at the molecular level. Furthermore, negative effects on normal cells occur concurrently. Strategies that minimize the negative effects on normal cells while efficiently targeting infected cells are required. Nanotherapies, according to recent research, may be one option in this direction. The present study differs from previously published review studies as it concentrates on examining the most recently developed nanoparticles for anti-mycobacterial purposes. Such novel approaches have the potential to reduce harmful side effects and improve patients' health prognoses. Current paper provides a comprehensive analysis of recent advances in nanotherapy systems for the pulmonary delivery of anti-tuberculous drugs. In addition, to low-priced and convenient alternatives for pulmonary delivery, different types of NPs for oral and topical application were also deliberated and summarized in this review.

Integrating pathogen- and host-derived blood biomarkers for enhanced tuberculosis diagnosis: a comprehensive review

This review explores the evolving landscape of blood biomarkers in the diagnosis of tuberculosis (TB), focusing on biomarkers derived both from the pathogen and the host. These biomarkers provide critical insights that can improve diagnostic accuracy and timeliness, essential for effective TB management. The document highlights recent advancements in molecular techniques that have enhanced the detection and characterization of specific biomarkers. It also discusses the integration of these biomarkers into clinical practice, emphasizing their potential to revolutionize TB diagnostics by enabling more precise detection and monitoring of the disease progression. Challenges such as variability in biomarker expression and the need for standardized validation processes are addressed to ensure reliability across different populations and settings. The review calls for further research to refine these biomarkers and fully harness their potential in the fight against TB, suggesting a multidisciplinary approach to overcome existing barriers and optimize diagnostic strategies. This comprehensive analysis underscores the significance of blood biomarkers as invaluable tools in the global effort to control and eliminate TB.

Introducing the NUATEI Consortium: A Mexican Research Program for the Identification of Natural and Synthetic Antimicrobial Compounds for Prevalent Infectious Diseases

The need for new drugs to treat human infections is a global health concern. Diseases like tuberculosis, trypanosomiasis, amoebiasis, and AIDS remain significant problems, especially in developing countries like Mexico. Despite existing treatments, issues such as resistance and adverse effects drive the search for new alternatives. Herein, we introduce the NUATEI research consortium, made up of experts from the Institute of Biomedical Research at UNAM, who identify and obtain natural and synthetic compounds and test their effects against human pathogens using in vitro and in vivo models. The consortium has evaluated hundreds of natural extracts and compounds against the pathogens causing tuberculosis, trypanosomiasis, amoebiasis, and AIDS, rendering promising results, including a patent with potential for preclinical studies. This paper presents the rationale behind the formation of this consortium, as well as its objectives and strategies, emphasizing the importance of natural and synthetic products as sources of antimicrobial compounds and the relevance of the diseases studied. Finally, we briefly describe the methods of the evaluation of the compounds in each biological model and the main achievements. The potential of the consortium to screen numerous compounds and identify new therapeutic agents is highlighted, demonstrating its significant contribution to addressing these infectious diseases.

Current approaches for diagnosis of subclinical pulmonary tuberculosis, clinical implications and future perspectives: a scoping review

INTRODUCTION

Subclinical tuberculosis (TB) is the presence of TB disease among people who are either asymptomatic or have minimal symptoms.

AREAS COVERED

Currently, there are no accurate diagnostic tools and clear treatment approaches for subclinical TB. In this study, a comprehensive literature search was conducted across major databases. This review aimed to uncover the latest advancements in diagnostic approaches, explore their clinical implications, and outline potential future perspectives. While innovative technologies are in development to enable sputum-free TB tests, there remains a critical need for precise diagnostic tools tailored to the unique characteristics of subclinical TB. Given the complexity of subclinical TB, a multidisciplinary approach involving clinicians, microbiologists, epidemiologists, and public health experts is essential. Further research is needed to establish standardized diagnostic criteria and treatment guidelines specifically tailored for subclinical TB, acknowledging the unique challenges posed by this elusive stage of the disease.

EXPERT OPINION

Efforts are needed for the detection, diagnosis, and treatment of subclinical TB. In this review, we describe the importance of subclinical TB, both from a clinical and public health perspective and highlight the diagnostic and treatment gaps of this stage.

Chest Radiograph Screening for Detecting Subclinical Tuberculosis in Asymptomatic Household Contacts, Peru

The World Health Organization's end TB strategy promotes the use of symptom and chest radiograph screening for tuberculosis (TB) disease. However, asymptomatic early states of TB beyond latent TB infection and active disease can go unrecognized using current screening criteria. We conducted a longitudinal cohort study enrolling household contacts initially free of TB disease and followed them for the occurrence of incident TB over 1 year. Among 1,747 screened contacts, 27 (52%) of the 52 persons in whom TB subsequently developed during follow-up had a baseline abnormal radiograph. Of contacts without TB symptoms, persons with an abnormal radiograph were at higher risk for subsequent TB than persons with an unremarkable radiograph (adjusted hazard ratio 15.62 [95% CI 7.74-31.54]). In young adults, we found a strong linear relationship between radiograph severity and time to TB diagnosis. Our findings suggest chest radiograph screening can extend to detecting early TB states, thereby enabling timely intervention.

Timely Pulmonary Tuberculosis Diagnosis Based on the Epidemiological Disease Spectrum: Population-Based Prospective Cohort Study in the Republic of Korea

BACKGROUND

Timely pulmonary tuberculosis (PTB) diagnosis is a global health priority for interrupting transmission and optimizing treatment outcomes. The traditional dichotomous time-divided approach for addressing time delays in diagnosis has limited clinical application because the time delay significantly varies depending on each community in question.

OBJECTIVE

We aimed to reevaluate the diagnosis time delay based on the PTB disease spectrum using a novel scoring system that was applied at the national level in the Republic of Korea.

METHODS

The Pulmonary Tuberculosis Spectrum Score (PTBSS) was developed based on previously published proposals related to the disease spectrum, and its validity was assessed by examining both all-cause and PTB-related mortality. In our analysis, we integrated the PTBSS into the Korea Tuberculosis Cohort Registry. We evaluated various time delays, including patient, health care, and overall delays, and their system-associated variables in line with each PTBSS. Furthermore, we reclassified the scores into distinct categories of mild (PTBSS=0-1), moderate (PBTBSS=2-3), and severe (PBTBSS=4-6) using a multivariate regression approach.

RESULTS

Among the 14,031 Korean patients with active PTB whose data were analyzed from 2018 to 2020, 37% (n=5191), 38% (n=5328), and 25% (n=3512) were classified as having a mild, moderate, and severe disease status, respectively, according to the PTBSS. This classification can therefore reflect the disease spectrum of PTB by considering the correlation of the score with mortality. The time delay patterns differed according to the PTBSS. In health care delays according to the PTBSS, greater PTB disease progression was associated with a shorter diagnosis period, since the condition is microbiologically easy to diagnose. However, with respect to patient delays, the change in elapsed time showed a U-shaped pattern as PTB progressed. This means that a remarkable patient delay in the real-world setting might occur at both apical ends of the spectrum (ie, in both mild and severe cases of PTB). Independent risk factors for a severe PTB pattern were age (adjusted odds ratio 1.014) and male sex (adjusted odds ratio 1.422), whereas no significant risk factor was found for mild PTB.

CONCLUSIONS

Timely PTB diagnosis should be accomplished. This can be improved with use of the PTBSS, a simple and intuitive scoring system, which can be more helpful in clinical and public health applications compared to the traditional dichotomous time-only approach.

Tuberculosis infection and hypertension: prevalence estimates from the US National Health and Nutrition Examination Survey

OBJECTIVES

Tuberculosis infection (TBI) is marked by dynamic host-pathogen interactions with persistent low-grade inflammation and is associated with increased risk of cardiovascular diseases (CVD) including acute coronary syndrome, myocardial infarction and stroke. However, few studies assess the relationship between TBI and hypertension, an intermediate of CVD. We sought to determine the association between TBI and hypertension using data representative of the adult US population.

METHODS

We performed cross-sectional analyses using data from the 2011-2012 US National Health and Nutrition Examination Survey (NHANES). Eligible participants included adults with valid QuantiFERON-TB Gold In-Tube (QFT-GIT) test results who also had blood pressure measures and no history of TB disease. TBI was defined by a positive QFT-GIT. We defined hypertension by either elevated measured blood pressure levels (ie, systolic ≥130 mm Hg or diastolic ≥80 mm Hg) or known hypertension indications (ie, self-reported previous diagnosis or use of antihypertensive medications). Analyses were performed using robust quasi-Poisson regressions and accounted for the stratified probability sampling design of NHANES.

RESULTS

The overall prevalence of TBI was 5.7% (95% CI 4.7% to 6.7%) and hypertension was present among 48.9% (95% CI 45.2% to 52.7%) of participants. The prevalence of hypertension was higher among those with TBI (58.5%, 95% CI 52.4% to 64.5%) than those without TBI (48.3%, 95% CI 44.5% to 52.1%) (prevalence ratio (PR) 1.2, 95% CI 1.1 to 1.3). However, after adjusting for confounders, the prevalence of hypertension was similar for those with and without TBI (adjusted PR 1.0, 95% CI 1.0 to 1.1). The unadjusted prevalence of hypertension was higher among those with TBI versus no TBI, especially among individuals without CVD risk factors including those with normal body mass index (PR 1.6, 95% CI 1.2 to 2.0), euglycaemia (PR 1.3, 95% CI 1.1 to 1.5) or non-smokers (PR 1.2, 95% CI 1.1 to 1.4).

CONCLUSIONS

More than half of adults with TBI in the USA had hypertension. Importantly, we observed a relationship between TBI and hypertension among those without established CVD risk factors.

SUMMARY

The prevalence of hypertension was high (59%) among adults with TBI in the USA. In addition, we found that the prevalence of hypertension was significantly higher among adults with positive QFT without established hypertension risk factors.

Pregnancy Outcomes in Women Screened for Tuberculosis Infection in Swedish Antenatal Care

BACKGROUND

Tuberculosis (TB) disease has been associated with pregnancy complications. However, the potential impact of TB infection (TBI) on pregnancy outcome is unknown. To investigate this, we conducted a register-based study in immigrant women screened with QuantiFERON assays for TBI in antenatal care in Sweden.

METHODS

Women with history of immigration from TB-endemic countries were eligible for inclusion if national identification numbers and available QuantiFERON results obtained during pregnancy from 2014 to 2018 were available. QuantiFERON results were linked to data on maternal characteristics and pregnancy outcomes from the national Pregnancy and Patient Registers. TBI was defined as nil-corrected QuantiFERON result ≥0.35 IU/mL, in the absence of TB disease. Pregnancies in women with TB disease or human immunodeficiency virus were excluded, as were multiplex pregnancies, pregnancies resulting in miscarriage, and pregnancies occurring >10 years after immigration. Odds of defined adverse pregnancy outcomes were compared by maternal TBI status using mixed effects logistic regression with adjustment for maternal age and region of origin.

RESULTS

In total, 7408 women with 12 443 pregnancies were included. In multivariable analysis, stillbirth (adjusted odds ratio [AOR], 1.90; 95% confidence interval [CI], 1.13-3.21; P = .016), severe preeclampsia (AOR, 1.62; 95% CI, 1.03-2.56; P = .036), low birthweight (<2500 g; AOR, 1.38; 95% CI, 1.01-1.88; P = .041), and emergency cesarean section (AOR, 1.28; 95% CI, 1.02-1.63; P = .033) were significantly associated with TBI.

CONCLUSIONS

Among immigrant women seeking antenatal care in Sweden, TBI was independently associated with adverse pregnancy outcomes. Further studies are needed to corroborate these findings and to explore mechanisms involved.

Beyond latent and active tuberculosis: a scoping review of conceptual frameworks

There is growing recognition that tuberculosis (TB) infection and disease exists as a spectrum of states beyond the current binary classification of latent and active TB. Our aim was to systematically map and synthesize published conceptual frameworks for TB states. We searched MEDLINE, Embase and EMcare for review articles from 1946 to September 2023. We included 40 articles that explicitly described greater than two states for TB. We identified that terminology, definitions and diagnostic criteria for additional TB states within these articles were inconsistent. Eight broad conceptual themes were identified that were used to categorize TB states: State 0: Mycobacterium tuberculosis (Mtb) elimination with innate immune response (n = 25/40, 63%); State I: Mtb elimination by acquired immune response (n = 31/40, 78%); State II: Mtb infection not eliminated but controlled (n = 37/40, 93%); State III: Mtb infection not controlled (n = 24/40, 60%); State IV: bacteriologically positive without symptoms (n = 26/40, 65%); State V: signs or symptoms associated with TB (n = 39/40, 98%); State VI: severe or disseminated TB disease (n = 11/40, 28%); and State VII: previous history of TB (n = 5/40, 13%). Consensus on a non-binary framework that includes additional TB states is required to standardize scientific communication and to inform advancements in research, clinical and public health practice.

From immunology to artificial intelligence: revolutionizing latent tuberculosis infection diagnosis with machine learning

Latent tuberculosis infection (LTBI) has become a major source of active tuberculosis (ATB). Although the tuberculin skin test and interferon-gamma release assay can be used to diagnose LTBI, these methods can only differentiate infected individuals from healthy ones but cannot discriminate between LTBI and ATB. Thus, the diagnosis of LTBI faces many challenges, such as the lack of effective biomarkers from Mycobacterium tuberculosis (MTB) for distinguishing LTBI, the low diagnostic efficacy of biomarkers derived from the human host, and the absence of a gold standard to differentiate between LTBI and ATB. Sputum culture, as the gold standard for diagnosing tuberculosis, is time-consuming and cannot distinguish between ATB and LTBI. In this article, we review the pathogenesis of MTB and the immune mechanisms of the host in LTBI, including the innate and adaptive immune responses, multiple immune evasion mechanisms of MTB, and epigenetic regulation. Based on this knowledge, we summarize the current status and challenges in diagnosing LTBI and present the application of machine learning (ML) in LTBI diagnosis, as well as the advantages and limitations of ML in this context. Finally, we discuss the future development directions of ML applied to LTBI diagnosis.

Prevalence of subclinical pulmonary tuberculosis and its association with HIV in household contacts of index tuberculosis patients in two South African provinces: a secondary, cross-sectional analysis of a cluster-randomised trial

Background

People with subclinical tuberculosis (TB) have microbiological evidence of disease caused by Mycobacterium tuberculosis, but either do not have or do not report TB symptoms. The relationship between human immunodeficiency virus (HIV) and subclinical TB is not yet well understood. We estimated the prevalence of subclinical pulmonary TB in household contacts of index TB patients in two South African provinces, and how this differed by HIV status.

Methods

This was a cross-sectional, secondary analysis of baseline data from the intervention arm of a household cluster randomised trial. Prevalence of subclinical TB was measured as the number of household contacts aged ≥ 5 years who had positive sputum TB microscopy, culture or nucleic acid amplification test (Xpert MTB/Rif or Xpert Ultra) results on a single sputum specimen and who did not report current cough, fever, weight loss or night sweats on direct questioning. Regression analysis was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for the association between HIV status and subclinical TB; adjusting for province, sex and age in household contacts; and HIV status in index patients.

Results

Amongst household contacts, microbiologically confirmed prevalent subclinical TB was over twice as common as symptomatic TB disease (48/2077, 2.3%, 95% CI 1.7-3.1% compared to 20/2077, 1.0%, 95% CI 0.6-1.5%). Subclinical TB prevalence was higher in people living with HIV (15/377, 4.0%, 95% CI 2.2-6.5%) compared to those who were HIV-negative (33/1696, 1.9%, 95% CI 1.3-2.7%; p = 0.018). In regression analysis, living with HIV (377/2077, 18.2%) was associated with a two-fold increase in prevalent subclinical TB with 95% confidence intervals consistent with no association through to a four-fold increase (adjusted OR 2.00, 95% CI 0.99-4.01, p = 0.052). Living with HIV was associated with a five-fold increase in prevalent symptomatic TB (adjusted OR 5.05, 95% CI 2.22-11.59, p < 0.001).

Conclusions

Most (70.6%) pulmonary TB diagnosed in household contacts in this setting was subclinical. Living with HIV was likely associated with prevalent subclinical TB and was associated with prevalent symptomatic TB. Universal sputum testing with sensitive assays improves early TB diagnosis in subclinical household contacts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s44263-023-00022-5.

Prior Screening for Latent Tuberculosis Among Patients Diagnosed With Tuberculosis Disease: Missed Opportunities?

Background

California has the largest number of tuberculosis (TB) disease cases in the United States. This study in a large California health system assessed missed opportunities for latent tuberculosis (LTBI) screening among patients with TB disease.

Methods

Kaiser Permanente Southern California patients who were ≥18 years old with membership for ≥24 months during the study period from 1 January 2008 to 31 December 2019 were included. Prior LTBI test (tuberculin skin test or interferon-γ release assay) or diagnosis code prior to TB disease diagnosis was assessed among patients with observed TB disease (confirmed by polymerase chain reaction and/or culture). In the absence of current treatment practices, more patients screened for LTBI may have developed TB disease. We estimated hypothetical TB disease cases prevented by multiplying LTBI progression rates by the number of LTBI-positive patients prescribed treatment.

Results

A total of 1289 patients with observed TB disease were identified; 148 patients were LTBI positive and 84 were LTBI negative. Patients not prescreened for LTBI made up 82.0% of observed TB disease cases (1057/1289). Adding the hypothetical maximum estimate for prevented cases decreased the percentage of patients who were not prescreened for LTBI to 61.7% [1057/(1289 + 424)].

Conclusions

One-fifth of patients were screened for LTBI prior to their active TB diagnosis. Assuming the upper bound of cases prevented through current screening, almost 62% of TB disease patients were never screened for LTBI. Future work to elucidate gaps in LTBI screening practices and to identify opportunities to improve screening guidelines is needed.

Latent Tuberculosis: Challenges in Diagnosis and Treatment, Perspectives, and the Crucial Role of Biomarkers

Tuberculosis (TB) is the major cause of morbidity and mortality globally, which is caused by a single infectious agent Mycobacterium tuberculosis. For years, many TB control programmes are established for effective diagnosis and treatment of active TB cases, but these approaches alone are insufficient for TB eradication. This review aims to discourse on the crucial management of latent tuberculosis infection. This review will first summarize the current status, and methods for diagnosing latent tuberculosis then describes the challenges involved in the diagnosis and treatment of latent tuberculosis, and finally encounters the purpose of biomarkers as predicting tool in latent tuberculosis.

Determinants of Unsuccessful TB Treatment Outcomes Among Patients on Directly Observed Treatment Short Course in Jimma Town Health Facilities, Southwest Ethiopia: A Case-Control Study

Background

Even though Ethiopia's Federal Ministry of Health has been implementing several programs aimed at reducing the burden of tuberculosis (TB), It does not demonstrate adequate progress. As a result, identifying the determinants of unsuccessful outcomes of directly observed treatment, short-course (DOTS) is critical.

Purpose

This study aimed to assess the determinants of unsuccessful TB treatment outcomes among patients with DOTS in Jimma town, southwest Ethiopia.

Patients and Methods

An unmatched case-control study using secondary data was conducted among 118 cases and 472 controls from April 1 to June 1, 2021. Cases were TB cases with unsuccessful treatment courses whereas controls were those of successful treatment. Data were collected using a standardized tool. Statistical analysis was done using SPSS version 23 software. A binary logistic regression model was used to identify the determinants.

Results

We found that the determinants including age > 35 years (AOR=1.9, 95% CI: 1.14-3.2), lack of contact person (AOR= 27, 95% CI: 15.8-46.3), being HIV positive (AOR=7.3, 95% CI: 3.7-14.2)), and being malnourished (AOR=4.5, 95% CI: 1.5-12.9) were significantly associated with unsuccessful tuberculosis treatment outcome.

Conclusion

In this study, advanced age, being HIV positive, lack of contact person, and being malnourished were determinant factors for unsuccessful TB treatment outcomes. Hence, careful monitoring, screening, and management of risk factors are recommended.

Bridging the Gaps: Investigating the Complex Impact of the COVID-19 Pandemic on Tuberculosis Records in Brazil

BACKGROUND

This study aimed to analyze the temporal evolution, spatial distribution, and impact of the COVID-19 pandemic on tuberculosis records in a northeastern state of Brazil.

METHODS

This is an ecological study involving all diagnoses of Tuberculosis (TB) in residents of the state of Pernambuco/Brazil. Data were extracted from the National System of Notifiable Diseases. A pre-pandemic COVID-19 temporal analysis (2001-2019), a spatial analysis before (2015-2019) and during the first two pandemic years (2020-2021), and the impact of the COVID-19 pandemic on cases of TB diagnoses in Pernambuco in the years 2020 and 2021 were performed. Inflection point regression models, Global and Local Moran's statistics, and spatial scan statistics were used.

RESULTS

In the period from 2001 to 2019, 91,225 cases of TB were registered in Pernambuco (48.40/100,000 inhabitants), with a tendency of growth starting in 2007 (0.7% per year; p = 0.005). In the pre-pandemic period (2015-2019), 10.8% (n = 20) of Pernambuco municipalities had TB incidence rates below 10/100,000. In 2020, this percentage reached 27.0% (n = 50) and in 2021 it was 17.8% (n = 33). Risk clusters were identified in the eastern region of the state, with five clusters in the pre-pandemic period and in 2021 and six in 2020. In the first year of the pandemic, an 8.5% reduction in the number of new TB cases was observed. In 2021, the state showed a slight increase (1.1%) in the number of new TB cases.

CONCLUSIONS

The data indicate that the COVID-19 pandemic may have caused a reduction in the number of new TB case reports in the state of Pernambuco, Brazil.

Spectrum of TB Disease and Treatment Outcomes in a Mobile Community Based Active Case Finding Program in Yogyakarta Province, Indonesia

The World Health Organization recommends using chest X-ray (CXR) in active case finding (ACF) to improve case detection. This study aimed to describe the spectrum and outcomes of TB disease diagnosed through a mobile community based ACF program in Yogyakarta. This prospective cohort study included people attending a TB ACF program in Yogyakarta between 1 January 2021 to 30 June 2022. Participants ≥10 years old underwent CXR, symptom screening, and Xpert MTB/RIF testing of sputum. Subclinical TB was defined as asymptomatic active TB, whether bacteriologically confirmed or not. Treatment outcome data were obtained from the national program TB database. 47,735 people attended the ACF program; the yield of TB disease was 0.86% (393/45,938). There were 217 symptomatic cases, of whom 72 (33.2%) were bacteriologically confirmed, and 176 asymptomatic cases, with 52 (29.5%) bacteriologically confirmed. Treatment success was 70.7% with high loss to follow up (9%) and not evaluated (17.1%). Multivariate analysis demonstrated weak evidence for lower unsuccessful outcomes in symptomatic versus subclinical TB (aOR 0.6, 95% CI 0.36-0.998). TB ACF programs utilizing CXR may diagnose a high proportion of subclinical TB. Linkage to care in ACF program is important to increase successful treatment outcomes.

The ubiquitin ligase TRIM32 promotes the autophagic response to Mycobacterium tuberculosis infection in macrophages

Mycobacterium tuberculosis (Mtb) is known to evade host immune responses and persist in macrophages for long periods. A mechanism that the host uses to combat Mtb is xenophagy, a selective form of autophagy that targets intracellular pathogens for degradation. Ubiquitination of Mtb or Mtb-containing compartments is a key event to recruit the autophagy machinery and mediate the bacterial delivery to the lysosome. This event relies on the coordinated and complementary activity of different ubiquitin ligases, including PARKIN, SMURF1, and TRIM16. Because each of these factors is responsible for the ubiquitination of a subset of the Mtb population, it is likely that additional ubiquitin ligases are employed by macrophages to trigger a full xenophagic response during Mtb infection. In this study, we investigated the role TRIM proteins whose expression is modulated in response to Mtb or BCG infection of primary macrophages. These TRIMs were ectopically expressed in THP1 macrophage cell line to assess their impact on Mtb replication. This screening identified TRIM32 as a novel player involved in the intracellular response to Mtb infection, which promotes autophagy-mediated Mtb degradation. The role of TRIM32 in xenophagy was further confirmed by silencing TRIM32 expression in THP1 cells, which causes increased intracellular growth of Mtb associated to impaired Mtb ubiquitination, reduced recruitment of the autophagy proteins NDP52/CALCOCO2 and BECLIN 1/BECN1 to Mtb and autophagosome formation. Overall, these findings suggest that TRIM32 plays an important role in the host response to Mtb infection through the induction of autophagy, representing a promising target for host-directed tuberculosis therapies.

Latent Tuberculosis Infection and Associated Risk Factors among People Living with HIV and HIV-Uninfected Individuals in Lithuania

BACKGROUND

People living with HIV (PLHIV) with latent tuberculosis infection (LTBI) are at increased risk of tuberculosis (TB) reactivation compared to the HIV-negative population. Lithuania belongs to the 18 high-priority TB countries in the European region. The aim of this study was to compare the prevalence of LTBI and LTBI-related risk factors between PLHIV and HIV-uninfected populations.

METHODS

A cross-sectional study was conducted in three Lithuanian Infectious Diseases centres from August 2018 to May 2022 using the interferon gamma release assay (IGRA) and tuberculin skin test (TST) in Vilnius, and IGRA only in Siauliai and Klaipeda. Cohen's kappa was used to assess IGRA and TST agreement. A structured questionnaire was completed by the study participants. LTBI-related risk factors were identified using a multivariable logistic regression model.

RESULTS

In total, 391 PLHIV and 443 HIV-uninfected individuals enrolled, with a median age of 41 (IQR 36-48) and 43 (IQR 36-50), consisting of 69.8% and 65.5% male, respectively. The prevalence of LTBI defined by positive IGRA and/or TST among PLHIV was higher compared to that in the HIV-uninfected population (20.5% vs. 15.3%; OR 1.42; 95% CI 1.02-2.03; p = 0.04). The concordance between IGRA and TST was fair: kappa = 0.23 (95% CI 0.09-0.34). In multivariable analyses, association with injecting drug use (IDU) (ORa 2.25, 95% CI 1.27-3.99, p = 0.01) and imprisonment (ORa 1.99, 95% CI 1.13-3.52, p = 0.02) in all participants, IDU (ORa 2.37, 95% CI 1.09-5.15; p = 0.029) in PLHIV and a history of contact with an active TB patient (ORa 3.33, 95% CI 1.53-7.24; p = 0.002) in HIV-uninfected individuals were significant associations evidenced by LTBI.

CONCLUSIONS

The prevalence of LTBI among PLHIV in Lithuania is higher compared to that in the HIV-uninfected population and the European average. The association with IDU in PLHIV emphasizes the need for integrated HIV, TB and substance abuse treatment to provide patient-centred care.

Detection of Mycobacterial DNA in Human Bone Marrow

Bone marrow is a cell-rich tissue of the reticuloendothelial system essential in the homeostasis and accurate functioning of hematopoiesis and of the immune system; moreover, it is also rich in lipids because it contains marrow adipocytes. This work aimed to evaluate the detection of mycobacterial DNA in human bone marrow as a tool to understand the complex pathology caused by the main pathogen Mycobacterium tuberculosis (Mtb). Formalin-fixed paraffin-embedded human bone marrow samples were studied using both conventional PCR + hybridization and in situ PCR to figure out the cell distribution of the targeted DNA. Samples were retrospectively collected from HIV+ patients with microbiologically proved mycobacterial infection and from subjects without evidence of infection. Mycobacterium avium (Mav) as well as Mtb DNA was detected in both settings, including tissues with and without granulomas. We detected DNA from both mycobacterial species, using in situ PCR, inside bone marrow macrophages. Other cell types, including adipocytes, showed positive signals only for Mtb DNA. This result suggested, for the first time, that marrow adipocytes could constitute an ideal reservoir for the persistence of Mtb, allowing the bacilli to establish long-lasting latent infection within a suitable lipid environment. This fact might differentiate pathogenic behavior of non-specialized pathogens such as Mav from that of specialized pathogens such as Mtb.

Research tests for the diagnosis of tuberculosis infection

INTRODUCTION

Despite huge efforts, tuberculosis (TB) is still a major public health threat worldwide, it is estimated that a quarter of the global population is infected by Mycobacterium tuberculosis (Mtb). For controlling TB and reducing Mtb transmission it is fundamental to diagnose TB infection (TBI) as well as the progressors from TBI to disease to identify those requiring preventive therapy. At present, there is no gold standard test for TBI diagnosis although several new methodologies have been attempted.

AREAS COVERED

This review provides an update on the most recent approaches to develop reliable tests to diagnose TBI and progressors from infection to disease. Experimental tests are based on either the direct identification of Mtb (i.e., Mtb DNA upon host cells isolation; Mtb proteins or peptides) or host response (i.e., levels and quality of specific anti-Mtb antibodies; host blood transcriptome signatures).

EXPERT OPINION

The experimental tests described are very interesting. However, further investigation and randomized clinical trials are needed to improve the sensitivity and specificity of these new research-based tests. More reliable proofs-of-concept and simplification of technical procedures are necessary to develop new diagnostic tools for identifying TBI patients and those that will progress from infection to TB disease.

Effect of Low Doses of Dexamethasone on Experimental Pulmonary Tuberculosis

Tuberculosis (TB) is the deadliest disease caused by a bacterial agent. Glucocorticoids (GCs) have a typical anti-inflammatory effect, but recently it has been shown that they can present proinflammatory activity, mainly by increasing molecules from innate immunity. In the current study, we evaluated the effect of low doses of dexamethasone on Mycobacterium tuberculosis in vivo and in vitro. We used an established mice model of progressing tuberculosis (TB) in the in vivo studies. Intratracheal or intranasal dexamethasone therapy administered with conventional antibiotics in the late stage of the disease decreased the lung bacilli load and lung pneumonia, and increased the survival of the animals. Finally, the treatment decreased the inflammatory response in the SNC and, therefore, sickness behavior and neurological abnormalities in the infected animals. In the in vitro experiments, we used a cell line of murine alveolar macrophages infected with Mtb. Low-dose dexamethasone treatment increased the clearance capacity of Mtb by MHS macrophages, MIP-1α, and TLR2 expression, decreased proinflammatory and anti-inflammatory cytokines, and induced apoptosis, a molecular process that contributes to the control of the mycobacteria. In conclusion, the administration of low doses of dexamethasone represents a promising adjuvant treatment for pulmonary TB.

Disease Transmission by Patients With Subclinical Tuberculosis

BACKGROUND

Subclinical tuberculosis has been increasingly recognized as a separate state in the spectrum of the disease. However, evidence on the transmissibility of subclinical tuberculosis is still inconclusive.

METHODS

We re-analyzed the data from the 2007 combined tuberculosis prevalence and tuberculin surveys in Vietnam. Poisson regression with robust standard errors was conducted to assess the effect of clinical presentation of individuals with tuberculosis in the household on tuberculin skin test (TST) positivity among children aged 6-14 years who participated in the tuberculin survey, adjusting for child's age, smear status of the index patient, and other covariates.

RESULTS

In the multivariate analysis, we found significantly increased risks for TST positivity in children living with patients with clinical, smear-positive tuberculosis, compared with those living with individuals without tuberculosis (adjusted risk ratio [aRR]: 3.04; 95% confidence interval [CI]: 2.00-4.63) and with those living with patients with subclinical tuberculosis, adjusting for index smear status (aRR: 2.26; 95% CI: 1.03-4.96). Among children aged 6-10 years, those living with patients with clinical, smear-positive tuberculosis and those living with patients with subclinical, smear-positive tuberculosis had similarly increased risks of TST positivity compared with those living with individuals without tuberculosis (aRRs [95% CI] of 3.56 [1.91-6.62] and 3.11 [1.44-6.72], respectively).

CONCLUSIONS

Our findings support the hypothesis that smear-positive subclinical tuberculosis contributes to Mycobacterium tuberculosis transmission. To eliminate tuberculosis in 2035, control strategies need to address subclinical presentations of the disease.

Updated considerations in the diagnosis and management of tuberculosis infection and disease: integrating the latest evidence-based strategies

INTRODUCTION

Tuberculosis (TB) is a leading infectious cause of global morbidity and mortality, affecting nearly a quarter of the human population and accounting for over 10 million deaths each year. Over the past several decades, TB incidence and mortality have gradually declined, but 2021 marked a threatening reversal of this trend highlighting the importance of accurate diagnosis and effective treatment of all forms of TB.

AREAS COVERED

This review summarizes advances in TB diagnostics, addresses the treatment of people with TB infection and TB disease including recent evidence for treatment regimens for drug-susceptible and drug-resistant TB, and draws attention to special considerations in children and during pregnancy.

EXPERT OPINION

Improvements in diagnosis and management of TB have expanded the available options for TB control. Molecular testing has enhanced the detection of TB disease, but better diagnostics are still needed, particularly for certain populations such as children. Novel treatment regimens have shortened treatment and improved outcomes for people with TB. However, important questions remain regarding the optimal management of TB. Work must continue to ensure the potential of the latest developments is realized for all people affected by TB.

Tuberculosis infection and hypertension: Prevalence estimates from the US National Health and Nutrition Examination Survey

Objectives

Latent Tuberculosis infection (LTBI) is marked by dynamic host-pathogen interactions with persistent low-grade inflammation and is associated with increased risk of cardiovascular diseases (CVD) including acute coronary syndrome, myocardial infarction, and stroke. However, few studies assess the relationship between LTBI and hypertension, an intermediate of CVD. We sought to determine the association between LTBI and hypertension using data representative of the adult US population.

Methods

We performed cross-sectional analyses using data from the 2011-2012 US National Health and Nutrition Examination Survey (NHANES). Eligible participants included adults with valid QuantiFERON-TB Gold In-Tube (QFT-GIT) test results who also had blood pressure measures and no history of TB disease. LTBI was defined by a positive QFT-GIT. We defined hypertension by either elevated measured blood pressure levels (i.e., systolic ≥130mmHg or diastolic ≥80mmHg) or known hypertension indications (i.e., self-reported previous diagnosis or use of antihypertensive medications). Analyses were performed using robust quasi-Poisson regressions and accounted for the stratified probability sampling design of NHANES.

Results

The overall prevalence of LTBI was 5.7% (95%CI 4.7-6.7) and hypertension was present among 48.9% (95%CI 45.2-52.7) of participants. The prevalence of hypertension was higher among those with LTBI (58.5%, 95%CI 52.4-64.5) than those without LTBI (48.3%, 95%CI 44.5-52.1) (prevalence ratio [PR]=1.2, 95%CI 1.1-1.3). However, after adjusting for confounders, the prevalence of hypertension was similar for those with and without LTBI (adjusted PR=1.0, 95%CI 0.9 -1.1). Among individuals without CVD risk factors of elevated BMI (PRnormal BMI=1.6, 95%CI 1.2-2.0), hyperglycemia (PReuglycemia=1.3, 95%CI 1.1-1.5), or cigarette smoking (PRnon-smokers=1.2, 95%CI 1.1-1.4), the unadjusted prevalence of hypertension was higher among those with LTBI vs. no LTBI.

Conclusions

More than half of adults with LTBI in the US had hypertension. Importantly, we observed a relationship between LTBI and hypertension among those without established CVD risk factors.

Migration and medical screening for tuberculosis

Vulnerable populations, such as migrants and refugees, have an increased risk of tuberculosis disease, especially in the first years after arrival in the host country. The presence of migrants and refugees in Brazil exponentially grew over the period between 2011 and 2020, and approximately 1.3 million migrants from the Global South were estimated to be residing in Brazil, most of whom from Venezuela and Haiti. Tuberculosis control programs for migrants can be divided into pre- and post-migration screening strategies. Pre-migration screening aims to identify cases of tuberculosis infection (TBI) and can be carried out in the country of origin (pre-entry) or in the destination country (at entry). Pre-migration screening can also detect migrants at an increased risk of developing tuberculosis in the future. High-risk migrants are then followed up in post-migration screening. In Brazil, migrants are considered a priority group for the active search for tuberculosis cases. However, there is no recommendation or plan regarding screening for TBI in migrants and refugees. Ensuring prevention, diagnosis, and treatment for TBI and tuberculosis disease in migrant populations is an important aspect of tuberculosis control and elimination. In this review article, we address epidemiological aspects and access to health care for migrants in Brazil. In addition, the migration medical screening for tuberculosis was reviewed.

Prevalence and management of tuberculosis infection in Apulian rheumatologic patients treated with biologics: An observational cohort 10-year study from the BIOPURE registry

INTRODUCTION

The objective of this study was to assess the 10-year prevalence of latent tuberculosis infection (LTBI) among Apulian patients with rheumatic diseases (RDs). Secondary endpoint was to record new cases of active TB disease and LTBI among patients treated with biologic disease-modifying antirheumatic drugs (bDMARDs).

METHODS

We analysed the results from the patients included in the BIOPURE registry from 2009 to 2018, who underwent QuantiFERON-TB Gold In-tube (QFT-GIT) test as screening before bDMARDs treatment. Demographic and clinical data were recorded at the time of the first QFT-GIT test. Administration of preventive therapy and bDMARD treatments were recorded for patients with positive QFT-GIT test. All new tuberculosis infections were recorded during the follow-up.

RESULTS

The final study population included 3028 patients (855 rheumatoid arthritis, 1001 psoriatic arthritis, 833 spondyloarthritis, 130 connective tissue diseases, 33 systemic vasculitis and 176 other inflammatory rheumatic conditions), more frequently female (67.2%), with a mean age of 52 ± 18 years. Patients with QFT-GIT-positive test were elderly people, predominantly male with higher prevalence of diabetes as comorbidity. The 10-year prevalence of LTBI was 10.8%. Of note, no cases of TB reactivation were recorded in patients who completed preventive therapy treatment. Three thousand and sixteen patients were followed over time (42.6 ± 30 months), and five (.2%) developed active TB, which corresponds to .47 cases per 1000 person-years.

CONCLUSIONS

In the 10-year observation, the use of bDMARDs seems to be safe in rheumatologic patients with positive QFT-GIT test treated according to current recommendations. Nevertheless, cases of primary TB disease did occur during treatment with biologicals.

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.

Management of Tuberculosis Infection: Current Situation, Recent Developments and Operational Challenges

Tuberculosis infection (TBI) is defined as a state of infection in which individuals host live Mycobacterium tuberculosis with or without clinical signs of active TB. It is now understood as a dynamic process covering a spectrum of responses to infection resulting from the interaction between the TB bacilli and the host immune system. The global burden of TBI is about one-quarter of the world’s population, representing a reservoir of approximately 2 billion people. On average, 5–10% of people who are infected will develop TB disease over the course of their lives, but this risk is enhanced in a series of conditions, such as co-infection with HIV. The End-TB strategy promotes the programmatic management of TBI as a crucial endeavor to achieving global targets to end the TB epidemic. The current development of new diagnostic tests capable of discriminating between simple TBI and active TB, combined with novel short-course preventive treatments, will help achieve this goal. In this paper, we present the current situation and recent developments of management of TBI and the operational challenges.

Transmission of tuberculosis in an incarcerated population during the subclinical period: A cross-sectional study in Qingdao, China

Objectives

As a closed gathering place, prison is the cradle of tuberculosis (TB) outbreak. Therefore, the analysis of the prevalence rate and risk factors of latent tuberculosis infection (LTBI) in prison will be a necessary measure to intervene in the spread of tuberculosis.

Methods

In this study, we consecutively recruited 506 adult prisoners in Qingdao to carry out this cross-sectional study. TB and LTBI were screened by IGRA, X-ray, X-pert, sputum smear and culture.

Results

A total of 17 TB, 101 LTBI and 388 HC were identified, with an infection rate of 23.32% (118/506) and a TB incidence rate of 3282/100,000 population. Age, malnutrition and inmates living with TB prisoners were risk factors for LTBI. Additionally, most TB cases (70.59%, 12/17) were subclinical tuberculosis (STB), contributing significantly to TB transmission.

Conclusion

Our results demonstrate that the transmission efficiency of asymptomatic patients is not essentially different from that of symptomatic patients, indicating that TB transmission occurs during the subclinical period. Our findings highlight the need to strengthen active case-finding strategies to increase TB case detection in this population.

Host blood-based biosignatures for subclinical TB and incipient TB: A prospective study of adult TB household contacts in Southern India

A large proportion of the global tuberculosis (TB) burden is asymptomatic and not detectable by symptom-based screening, driving the TB epidemic through continued M. tuberculosis transmission. Currently, no validated tools exist to diagnose incipient and subclinical TB. Nested within a large prospective study in household contacts of pulmonary TB cases in Southern India, we assessed 35 incipient TB and 12 subclinical TB cases, along with corresponding household active TB cases (n=11), and household controls (n=39) using high throughput methods for transcriptional and protein profiling. We split the data into training and test sets and applied a support vector machine classifier followed by a Lasso regression model to identify signatures. The Lasso regression model identified an 11-gene signature (ABLIM2, C20orf197, CTC-543D15.3, CTD-2503O16.3, HLADRB3, METRNL, RAB11B-AS1, RP4-614C10.2, RNA5SP345, RSU1P1, and UACA) that distinguished subclinical TB from incipient TB with a very good discriminatory power by AUCs in both training and test sets. Further, we identified an 8-protein signature comprising b-FGF, IFNγ, IL1RA, IL7, IL12p70, IL13, PDGF-BB, and VEGF that differentiated subclinical TB from incipient TB with good and moderate discriminatory power by AUCs in the training and test sets, respectively. The identified 11-gene signature discriminated well between the distinct stages of the TB disease spectrum, with very good discriminatory power, suggesting it could be useful for predicting TB progression in household contacts. However, the high discriminatory power could partly be due to over-fitting, and validation in other studies is warranted to confirm the potential of the immune biosignatures for identifying subclinical TB.

The spectrum of tuberculosis described as differential DNA methylation patterns in alveolar macrophages and alveolar T cells

BACKGROUND

Host innate immune cells have been identified as key players in the early eradication of Mycobacterium tuberculosis and in the maintenance of an anti-mycobacterial immune memory, which we and others have shown are induced through epigenetic reprogramming. Studies on human tuberculosis immunity are dominated by those using peripheral blood as surrogate markers for immunity. We aimed to investigate DNA methylation patterns in immune cells of the lung compartment by obtaining induced sputum from M. tuberculosis- exposed subjects including symptom-free subjects testing positively and negatively for latent tuberculosis as well as patients diagnosed with active tuberculosis. Alveolar macrophages and alveolar T cells were isolated from the collected sputum and DNA methylome analyses performed (Illumina Infinium Human Methylation 450 k).

RESULTS

Multidimensional scaling analysis revealed that DNA methylomes of cells from the tuberculosis-exposed subjects and controls appeared as separate clusters. The numerous genes that were differentially methylated between the groups were functionally connected and overlapped with previous findings of trained immunity and tuberculosis. In addition, analysis of the interferon-gamma release assay (IGRA) status of the subjects demonstrated that the IGRA status was reflected in the DNA methylome by a unique signature.

CONCLUSIONS

This pilot study suggests that M. tuberculosis induces epigenetic reprogramming in immune cells of the lung compartment, reflected as a specific DNA methylation pattern. The DNA methylation signature emerging from the comparison of IGRA-negative and IGRA-positive subjects revealed a spectrum of signature strength with the TB patients grouping together at one end of the spectrum, both in alveolar macrophages and T cells. DNA methylation-based biosignatures could be considered for further development towards a clinically useful tool for determining tuberculosis infection status and the level of tuberculosis exposure.