Acquired immunodeficiencies and tuberculosis: focus on HIV/AIDS and diabetes mellitus

Variations in Quinolinic Acid Levels in Tuberculosis Patients with Diabetes Comorbidity: A Pilot Prospective Cohort Study

Objective

We aimed to investigate dysregulated metabolic pathways and identify diagnostic and therapeutic targets in patients with tuberculosis-diabetes (TB-DM).

Methods

In our prospective cohort study, plasma samples were collected from healthy individuals, diabetic (DM) patients, untreated TB-only (TB-0)/TB-DM patients (TB-DM-0), and cured TB (TB-6)/TB-DM patients (TB-DM-6) to measure the levels of amino acids, fatty acids, and other metabolites in plasma using high-throughput targeted quantification methods.

Results

Significantly different biological processes and biomarkers were identified in DM, TB-DM-0, and TB-DM-6 patients. Moreover, quinolinic acid (QA) showed excellent predictive accuracy for distinguishing between DM patients and TB-DM-0 patients, with an AUC of 1 (95% CI 1-1). When differentiating between TB-DM-0 patients and TB-DM-6 patients, the AUC was 0.9297 (95% CI 0.8460-1). Compared to those in DM patients, the QA levels were significantly elevated in TB-DM-0 patients and decreased significantly after antituberculosis treatment. We simultaneously compared healthy controls and untreated tuberculosis patients and detected an increase in the level of QA in the plasma of tuberculosis patients, which decreased following treatment.

Conclusion

These findings improve the current understanding of tuberculosis treatment in patients with diabetes. QA may serve as an ideal diagnostic biomarker for TB-DM patients and contribute to the development of more effective treatments.

Antigen specificity shapes antibody functions in tuberculosis

Tuberculosis (TB) is the number one infectious disease cause of death worldwide due to an incomplete understanding of immunity. Emerging data highlight antibody functions mediated by the Fc domain as immune correlates. However, the mechanisms by which antibody functions impact the causative agent Mycobacterium tuberculosis (Mtb) are unclear. Here, we examine how antigen specificity determined by the Fab domain shapes Fc effector functions against Mtb. Using the critical structural and secreted virulence proteins Mtb cell wall and ESAT-6 & CFP-10, we observe that antigen specificity alters subclass, antibody post-translational glycosylation, and Fc effector functions in TB patients. Moreover, Mtb cell wall IgG3 enhances disease through opsonophagocytosis of extracellular Mtb . In contrast, polyclonal and a human monoclonal IgG1 we generated targeting ESAT-6 & CFP-10 inhibit intracellular Mtb . These data show that antibodies have multiple roles in TB and antigen specificity is a critical determinant of the protective and pathogenic capacity.

The Complex Immunological Alterations in Patients with Type 2 Diabetes Mellitus on Hemodialysis

It is widely known that diabetes mellitus negatively impacts both the innate immunity (the inflammatory response) and the acquired immunity (the humoral and cellular immune responses). Many patients with diabetes go on to develop chronic kidney disease, which will necessitate hemodialysis. In turn, long-term chronic hemodialysis generates an additional chronic inflammatory response and impairs acquired immunity. The purpose of this paper is to outline and compare the mechanisms that are the basis of the constant aggression towards self-components that affects patients with diabetes on hemodialysis, in order to find possible new therapeutic ways to improve the functionality of the immune system. Our study will take a detailed look at the mechanisms of endothelial alteration in diabetes and hemodialysis, at the mechanisms of inflammatory generation and signaling at different levels and also at the mechanisms of inflammation-induced insulin resistance. It will also discuss the alterations in leukocyte chemotaxis, antigen recognition and the dysfunctionalities in neutrophils and macrophages. Regarding acquired immunity, we will outline the behavioral alterations of T and B lymphocytes induced by diabetes mellitus and chronic hemodialysis.

C-reactive protein-based tuberculosis triage testing: a multi-country diagnostic accuracy study

Rationale

C-reactive protein (CRP)-based tuberculosis (TB) screening is recommended for people with HIV (PWH). However, its performance among people without HIV and in diverse settings is unknown.

Objectives

In a multi-country study, we aimed to determine whether CRP meets the minimum accuracy targets (sensitivity ≥90%, specificity ≥70%) for an effective TB triage test.

Methods/Measurements

Consecutive outpatient adults with cough ≥2 weeks from five TB endemic countries in Africa and Asia had baseline blood collected for point-of-care CRP testing and HIV and diabetes screening. Sputum samples were collected for Xpert MTB/RIF Ultra (Xpert) testing and culture. CRP sensitivity and specificity (5 mg/L cut-point) was determined in reference to sputum test results and compared by country, sex, and HIV and diabetes status. Variables affecting CRP performance were identified using a multivariate receiver operating characteristic (ROC) regression model.

Results

Among 2904 participants, of whom 613 (21%) had microbiologically-confirmed TB, CRP sensitivity was 84% (95% CI: 81-87%) and specificity was 61% (95% CI: 59-63%). CRP accuracy varied geographically, with higher sensitivity in African countries (≥91%) than Asian countries (64-82%). Sensitivity was higher among men than women (87% vs. 79%, difference +8%, 95% CI: 1-15%) and specificity was higher among people without HIV than PWH (64% vs. 45%, difference +19%, 95% CI: 13-25%). ROC regression identified country and measures of TB disease severity as predictors of CRP performance.

Conclusions

Overall, CRP did not achieve the minimum accuracy targets and its performance varied by setting and in some sub-groups, likely reflecting population differences in mycobacterial load.

Diabetes mellitus and human immunodeficiency virus (HIV) infection in people with tuberculosis in Odisha, India

BACKGROUND

Modelling studies have indicated that approximately 20% of all tuberculosis (TB) cases may suffer from diabetes mellitus (DM). DM increases the risk of developing active TB disease by 2-3 times. People living with HIV (PLHIV) are more likely to develop TB disease, and TB is a leading cause of hospitalization and death among PLHIV. Despite the substantial burden of DM and HIV in India, few studies have evaluated the prevalence of DM and HIV among active cases of TB, and its impact on the treatment outcome for TB. This study evaluated the burden of HIV and DM in TB cases from Odisha during 2019, and its impact on the TB treatment outcome.

METHODS

The study utilized data on TB patients of Odisha during 2019, from the NIKSHAY portal, the health management information system (HMIS) of TB in India. This is a retrospective observational registry-based cohort study, which evaluated a linkage between socio-demographic predictors, clinical diagnostic and treatment predictors, time of treatment predictors, and co-morbidity with TB. Data were retrieved electronically in Microsoft-Excel and analysis was done using STATA 16 (StataCorp. 2019, College Station, TX: StataCorp LLC).

RESULTS

Data for 47,831 TB cases of Odisha as study population was extracted from the Nikshay application for the year 2019. The highest prevalence (31.1%, 14,863/47,831) of TB was observed among young participants aged 15-30 years, whereas the prevalence was least among children <14 years (4.4%, 2124/47,831). Males had a higher prevalence of TB (66.7%, 31,878/47,831). Of the 47,831 TB cases included in the study, 7.6% (3659/47,831) had diabetes mellitus (DM), along with TB. 1.2% (571/47,831) had HIV along with TB, while only 0.08% (37/47,831) had both DM and HIV along with TB. 88.2% (3148/3569) of cases with DM and TB had a favorable outcome, compared to 82.3% (449/541) of cases with HIV and TB. People with TB who did not have DM had a significantly higher favorable outcome (OR 1.6, 95% CI 1.5-1.8) compared to those with TB and DM. Similarly, TB cases who did not have HIV infection had a significantly higher favorable outcome (OR 2.4, 95% CI 1.9-3.0) compared to those with TB and HIV.

CONCLUSION

Our study showed that presence of DM and/or HIV in TB patients had an impact on the TB treatment outcome. There is a crucial need to prevent comorbidities such as DM and HIV from occurring and to prioritize early diagnosis and management of these conditions.

The alterations of innate immunity and enhanced severity of infections in diabetes mellitus

Diabetes mellitus (DM) is a metabolic inflammatory disease with a high incidence worldwide. Patients with DM are at a high risk for all types of infections. Type 1 DM is characterised with immune destruction of pancreatic β cells, while type 2 diabetes is characterised with insulin resistance and β cell dysfunction, both of which result in disorders of glucose and lipid metabolism. This metabolic disorder causes functional defects of immune cells, aberrant production of inflammatory cytokines, dysregulated immune responses, advanced pathophysiological injury of the body, and increased mortality in populations with DM upon infections. Starting with the change of natural immune system in patients with DM, this paper focused on the enhanced severity of infections in DM and the underlying innate immune alterations in preclinical and clinical studies, aiming to better understand the influence of DM on the susceptibility, pathophysiology, and clinical outcomes in infections.

Examining Influenza Vaccination Patterns and Barriers: Insights into Knowledge, Attitudes, and Practices among Diabetic Adults (A Cross-Sectional Survey)

Diabetes mellitus is a prevalent global chronic condition affecting individuals of all ages. People with diabetes face an elevated risk of lower respiratory tract infections such as pulmonary tuberculosis, influenza, and pneumonia. Additionally, the influenza virus increases the likelihood of deep venous thrombosis and pulmonary embolism. This study examined the knowledge, attitudes, and practices of diabetic patients regarding the influenza vaccine. This study involved 418 diabetic patients (53.3% female) at Jordanian outpatient respiratory clinics, with an average age of 49 (±14) years. The results showed that 70.6% had never received the influenza vaccine, and only 23.7% intended to do so in the current year. A positive attitude toward the influenza vaccine significantly reduced hesitancy to get vaccinated (OR = 0.505, 95% CI 0.424-0.601, p < 0.001). The duration of diabetes exhibited a positive association with vaccine hesitancy (OR = 1.053, 95% CI 1.006-1.102, p = 0.028). The primary reason for not getting vaccinated was a lack of awareness of its benefits (42.6%). Future health education programs should emphasize the importance of the influenza vaccine for diabetic patients and address their concerns.

Diabetes Mellitus and Prevalence of Other Comorbid Conditions: A Systematic Review

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, severity continues to rise worldwide. This systematic review seeks to examine the prevalence of diabetes and its associated comorbid conditions, aiming to provide insights into the multifaceted impact of diabetes on a broader scale. DM exhibits a positive correlation with advancing age, and it's strongly influenced by genetic predisposition. In recent years, there has been a discernible global increase in the prevalence of type 1 diabetes (T1D), as evidenced by extensive epidemiological studies. Individuals with DM frequently have a positive familial history, and the presence of DM in both parents or solely the mother significantly amplifies genetic susceptibility. Moreover, non-genetic factors, such as acute psychological stressors, obesity, pregnancy, and smoking play a pivotal role in the development of DM. Notably, urinary tract infections (UTIs) are a common comorbidity in patients with type 2 diabetes (T2D) and all patients with T1D. T2D is prevalent, particularly among females, and its incidence rises with age. UTIs are prevalent among individuals with diabetes, particularly females, with Escherichia coli (E. coli) isolates being the primary etiological agents responsible for UTI inflammation. Insulin resistance is a common feature in both prediabetes and prehypertension, serving as a precursor to these conditions. The increasing incidence of T2D in regions with high tuberculosis (TB) prevalence emphasizes the significance of understanding DM as a substantial TB risk factor. DM is associated with a threefold elevation in TB risk and a twofold increase in unfavorable outcomes during TB treatment. Notably, the global prevalence of DM has led to a larger population of TB patients with comorbid DM than TB patients coinfected with HIV. Diabetes and sepsis contribute significantly to worldwide morbidity and mortality, with diabetic individuals experiencing more post-sepsis complications and increased mortality. The coexistence of hypertension and T2D is a common comorbidity, with hypertension incidence being twice as high among individuals with diabetes compared to those without, often linked to insulin resistance and a heightened risk of diabetes onset.

Bifurcation analysis of a tuberculosis progression model for drug target identification

Tuberculosis (TB) is a major cause of morbidity and mortality worldwide. The emergence and rapid spread of drug-resistant M. tuberculosis strains urge us to develop novel treatments. Experimental trials are constrained by laboratory capacity, insufficient funds, low number of laboratory animals and obsolete technology. Systems-level approaches to quantitatively study TB can overcome these limitations. Previously, we proposed a mathematical model describing the key regulatory mechanisms underlying the pathological progression of TB. Here, we systematically explore the effect of parameter variations on disease outcome. We find five bifurcation parameters that steer the clinical outcome of TB: number of bacteria phagocytosed per macrophage, macrophages death, macrophage killing by bacteria, macrophage recruitment, and phagocytosis of bacteria. The corresponding bifurcation diagrams show all-or-nothing dose-response curves with parameter regions mapping onto bacterial clearance, persistent infection, or history-dependent clearance or infection. Importantly, the pathogenic stage strongly affects the sensitivity of the host to these parameter variations. We identify parameter values corresponding to a latent-infection model of TB, where disease progression occurs significantly slower than in progressive TB. Two-dimensional bifurcation analyses uncovered synergistic parameter pairs that could act as efficient compound therapeutic approaches. Through bifurcation analysis, we reveal how modulation of specific regulatory mechanisms could steer the clinical outcome of TB.

Impaired resolution of blood transcriptomes through tuberculosis treatment with diabetes comorbidity

BACKGROUND

People with diabetes are more likely to develop tuberculosis (TB) and to have poor TB-treatment outcomes than those without. We previously showed that blood transcriptomes in people with TB-diabetes (TB-DM) co-morbidity have excessive inflammatory and reduced interferon responses at diagnosis. It is unknown whether this persists through treatment and contributes to the adverse outcomes.

METHODS

Pulmonary TB patients recruited in South Africa, Indonesia and Romania were classified as having TB-DM, TB with prediabetes, TB-related hyperglycaemia or TB-only, based on glycated haemoglobin concentration at TB diagnosis and after 6 months of TB treatment. Gene expression in blood at diagnosis and intervals throughout treatment was measured by unbiased RNA-Seq and targeted Multiplex Ligation-dependent Probe Amplification. Transcriptomic data were analysed by longitudinal mixed-model regression to identify whether genes were differentially expressed between clinical groups through time. Predictive models of TB-treatment response across groups were developed and cross-tested.

RESULTS

Gene expression differed between TB and TB-DM patients at diagnosis and was modulated by TB treatment in all clinical groups but to different extents, such that differences remained in TB-DM relative to TB-only throughout. Expression of some genes increased through TB treatment, whereas others decreased: some were persistently more highly expressed in TB-DM and others in TB-only patients. Genes involved in innate immune responses, anti-microbial immunity and inflammation were significantly upregulated in people with TB-DM throughout treatment. The overall pattern of change was similar across clinical groups irrespective of diabetes status, permitting models predictive of TB treatment to be developed.

CONCLUSIONS

Exacerbated transcriptome changes in TB-DM take longer to resolve during TB treatment, meaning they remain different from those in uncomplicated TB after treatment completion. This may indicate a prolonged inflammatory response in TB-DM, requiring prolonged treatment or host-directed therapy for complete cure. Development of transcriptome-based biomarker signatures of TB-treatment response should include people with diabetes for use across populations.

Rethinking the syndemic of tuberculosis and dysglycaemia: a Kenyan perspective on dysglycaemia as a neglected risk factor for tuberculosis

Background

The END TB 2035 goal has a long way to go in low-income and low/middle-income countries (LICs and LMICs) from the perspective of a non-communicable disease (NCD) control interaction with tuberculosis (TB). The World Health Organization has identified diabetes as a determinant for, and an important yet neglected risk factor for tuberculosis. National guidelines have dictated testing time points, but these tend to be at an isolated time point rather than over a period of time. This article aims to give perspective on the syndemic interaction of tuberculosis and dysglycaemia and how the gaps in addressing the two may hamper progress towards END TB 2035.

Main text

Glycated haemoglobin (HbA1C) has a strong predictive association with the progression to subsequent diabetes. Therefore, screening using this measure could be a good way to screen at TB initiation therapy, in lieu of using the random blood sugar or fasting plasma glucose only. HbA1C has an observed gradient with mortality risk making it an informative predictor of outcomes. Determining the progression of dysglycaemia from diagnosis to end of treatment and shortly after may offer information on the best time point to screen and follow-up. Despite TB and Human Immunodeficiency Virus (HIV) disease care being free, hidden costs remain. These costs are additive if there is accompanying dysglycaemia. Regardless of receiving TB treatment, it is estimated that almost half of persons affected by pulmonary TB develop post-TB lung disease (PTLD) as an outcome and the contribution of dysglycaemia is not well described.

Conclusions

Establishing costs of treating TB with diabetes/prediabetes alone and in the additional context of HIV co-infection will inform policy makers on what it takes, financially, to treat these patients and subsidize dysglycaemia care. In Kenya, cardiovascular disease is only rivalled by infectious disease as a cause of mortality, and diabetes is a well-described risk factor for cardiac disease. In poor countries, communicable diseases are responsible for majority of the mortality burden, but societal shifts and rural-urban migration may have contributed to the observed increase of NCDs.

Epidemiological cluster identification using multiple data sources: an approach using logistic regression

In the management of infectious disease outbreaks, grouping cases into clusters and understanding their underlying epidemiology are fundamental tasks. In genomic epidemiology, clusters are typically identified either using pathogen sequences alone or with sequences in combination with epidemiological data such as location and time of collection. However, it may not be feasible to culture and sequence all pathogen isolates, so sequence data may not be available for all cases. This presents challenges for identifying clusters and understanding epidemiology, because these cases may be important for transmission. Demographic, clinical and location data are likely to be available for unsequenced cases, and comprise partial information about their clustering. Here, we use statistical modelling to assign unsequenced cases to clusters already identified by genomic methods, assuming that a more direct method of linking individuals, such as contact tracing, is not available. We build our model on pairwise similarity between cases to predict whether cases cluster together, in contrast to using individual case data to predict the cases' clusters. We then develop methods that allow us to determine whether a pair of unsequenced cases are likely to cluster together, to group them into their most probable clusters, to identify which are most likely to be members of a specific (known) cluster, and to estimate the true size of a known cluster given a set of unsequenced cases. We apply our method to tuberculosis data from Valencia, Spain. Among other applications, we find that clustering can be predicted successfully using spatial distance between cases and whether nationality is the same. We can identify the correct cluster for an unsequenced case, among 38 possible clusters, with an accuracy of approximately 35 %, higher than both direct multinomial regression (17 %) and random selection (< 5 %).

Experiences and perceptions of participants on the pathway towards clinical management of dual tuberculosis and diabetes mellitus in Tanzania

BACKGROUND

Diabetes mellitus (DM) is a common comorbidity among people with tuberculosis (TB). Despite the availability of guidelines on how to integrate dual TB/DM in Tanzania, the practice of integration at various healthcare levels is unclear.

OBJECTIVE

To explore the participants' experiences and perceptions on the pathway towards clinical management of dual TB/DM.

METHOD

The research was carried out in Dar es Salaam, Iringa, and Kilimanjaro regions between January and February 2020. A qualitative, in-depth interview approach was used to collect participants' experiences and perspectives on the acquisition of dual TB/DM services at various levels of healthcare facilities. The information gathered were coded and classified thematically.

RESULTS

The participants' perception of TB services within the healthcare facilities was positive due to the support they received from the healthcare providers. On the other hand, participants reported difficulty receiving management in various health facilities for each condition in terms of access to dual TB/DM care and access to DM medication. This was viewed as a significant challenge for the participants with dual TB/DM.

CONCLUSIONS

The current disjunction and disruption in healthcare for people with dual TB/DM makes it difficult to access services at various levels of health facilities. For optimal clinical management for people with dual TB/DM, patient-centered strategies and integrated approaches are urgently needed.

Transcriptome analysis of the impact of diabetes as a comorbidity on tuberculosis

BACKGROUND

Diabetes mellitus patients with pulmonary tuberculosis (DMTB) comorbidity has been recognized as a major obstacle towards achieving the World Health Organization goal of reducing the tuberculosis incidence rate by 90% in 2035. Host immune responses affected by diabetes can lead to increased susceptibility, severity and poor treatment outcomes in DMTB patients, and the underlying mechanisms have not yet been fully elucidated. This study aimed to identify key immunological and cellular components that contribute to increased morbidity and mortality in DMTB cases.

METHODS

We performed RNA-Seq of total RNA isolated from peripheral blood mononuclear cells from 3 TB, 3 diabetes mellitus, and 3 DMTB patients and healthy controls, and analyzed differential expression, pathway enrichment and clustering of differentially-expressed genes (DEGs) to identify biological pathways altered specifically in DMTB patients.

RESULTS

Bioinformatic analysis of DEGs suggested that enhanced inflammatory responses, small GTPases, the protein kinase C signaling pathway, hemostasis and the cell cycle pathway are likely implicated in the pathogenesis of the DMTB comorbidity.

CONCLUSION

The DMTB comorbidity is associated with an altered transcriptome and changes in various biological pathways. Our study provides new insights on the pathological mechanism that may aid the development of host-directed therapies for this increasingly prevalent disease in high TB burden countries.

Leptin mutation and mycobacterial infection lead non-synergistically to a similar metabolic syndrome

INTRODUCTION

The leptin signaling pathway plays an important role as a key regulator of glucose homeostasis, metabolism control and systemic inflammatory responses. However, the metabolic effects of leptin on infectious diseases, for example tuberculosis (TB), are still little known.

OBJECTIVES

In this study, we aim to investigate the role of leptin on metabolism in the absence and presence of mycobacterial infection in zebrafish larvae and mice.

METHODS

Metabolites in entire zebrafish larvae and the blood of mice were studied using high-resolution magic-angle-spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy and mass spectrometry, respectively. For transcriptome studies of zebrafish larvae, deep RNA sequencing was used.

RESULTS

The results show that leptin mutation leads to a similar metabolic syndrome as caused by mycobacterial infection in the two species, characterized by the decrease of 11 amine metabolites. In both species, this metabolic syndrome was not aggravated further when the leptin mutant was infected by mycobacteria. Therefore, we conclude that leptin and mycobacterial infection are both impacting metabolism non-synergistically. In addition, we studied the transcriptomes of lepb^ibl54 mutant zebrafish larvae and wild type (WT) siblings after mycobacterial infection. These studies showed that mycobacteria induced a very distinct transcriptome signature in the lepb^ibl54 mutant zebrafish compared to WT sibling control larvae. Furthermore, lepb^ibl55 Tg (pck1:luc1) zebrafish line was constructed and confirmed this difference in transcriptional responses.

CONCLUSIONS

Leptin mutation and TB lead non-synergistically to a similar metabolic syndrome. Moreover, different transcriptomic responses in the lepb^ibl54  mutant and TB can lead to the similar metabolic end states.

Head-to-head comparison of the efficacy of Xpert MTB/RIF Ultra and Xpert MTB/RIF for the diagnosis of tuberculous pleurisy: A systematic review and meta-analysis

BACKGROUND

The aim of this study was to evaluate the diagnostic accuracy of Xpert MTB/RIF Ultra (Xpert Ultra) and Xpert MTB/RIF (Xpert) for the diagnosis of tuberculous pleurisy (TBP) head-to-head using meta-analysis method.

METHODS

On May 12, 2021, we searched multiple databases for reports that used Xpert Ultra and Xpert for TBP diagnosis head-to-head and screened eligible studies for inclusion. Accuracy of Xpert Ultra and Xpert were compared to that of the composite reference standard (CRS) and culture. When heterogeneity was evident, sources of heterogeneity were explored using subgroup analyses, sensitivity analysis, and meta-regression analyses.

RESULTS

Five articles met the inclusion criteria for meta-analysis. When results from different specimens or different reference standards were reported in the same article, we analyzed them as separate studies. Thus, 6 studies compared Xpert Ultra and Xpert with CRS, 5 studies compared Xpert Ultra and Xpert with culture. Pooled sensitivity and specificity of Xpert Ultra were 52% and 98% compared to CRS, and 82% and 77% compared to culture. Pooled sensitivity and specificity of Xpert were 22% and 99% compared to CRS, and 48% and 94% compared to culture. Significant heterogeneity in sensitivity was observed compared to CRS.

CONCLUSION

The sensitivity of Xpert Ultra was moderate but better than that of the Xpert; however, its specificity was lower. The role of Xpert Ultra and Xpert in the early and rapid diagnosis of TBP was limited.

Impact of Diabetes Mellitus on the Immunity of Tuberculosis Patients: A Retrospective, Cross-Sectional Study

Background

Tuberculosis (TB) is an infectious disease that poses a significant health threat and is one of the leading causes of death worldwide. Diabetes mellitus (DM) has high morbidity and mortality rates. Previous studies have reported that comorbidities can influence one another and aggravate immune disorders. A systematic and comprehensive evaluation of the immune status of patients with TB and DM (TB-DM) is helpful for early clinical immune intervention and for promoting the recovery of patients with TB-DM.

Methods

This study included 159 patients with TB without DM (TB-NDM) and 168 patients with TB-DM. Interferon-γ (IFN-γ) release assays (IGRAs) and TB-specific antibodies against 38kD+16kD proteins were used to detect humoral and cellular immune responses. Flow cytometry was used to analyze the absolute counts of the lymphocyte subsets.

Results

There was no significant difference in the positive rate of enzyme-linked immunospot (ELISPOT) assays, enzyme linked immunosorbent assay (ELISA), and 38kD+16kD antibodies between the TB-DM and TB-NDM groups. Pulmonary lobe lesion and cavity formation rates were significantly higher in patients with TB-DM with poor glycemic control than patients with TB-NDM and TB-DM with normal glycemic control. The absolute counts of T lymphocytes, CD8+ T lymphocytes, and B lymphocytes in patients with TB-DM were markedly lower than those in patients with TB-NDM. The absolute counts of T lymphocytes and CD8+ T lymphocytes in patients with TB-DM and hyperglycemia were lower than those in patients with euglycemia. Linear regression analysis revealed that the absolute counts of total T lymphocytes, CD8+ T lymphocytes, and NK cells in patients with TB-DM significantly decreased with increasing fasting blood glucose (FBG) levels.

Conclusion

Hyperglycemia is a risk factor for pulmonary cavity formation and lobe lesions in patients with TB-DM and suppresses the absolute counts of total T lymphocytes, CD8+ T lymphocytes, and NK cells in patients with TB-DM. The potential mechanism may involve the downregulation of innate and adaptive immune responses.

The role of Wnt pathway in obesity induced inflammation and diabetes: a review

Diabetes has become a major killer worldwide and at present, millions are affected by it. Being a chronic disease it increases the risk of other diseases ranging from pulmonary disorders to soft tissue infections. The loss of insulin-producing capacity of the pancreatic β-cells is the main reason for the development of the disease. Obesity is a major complication that can give rise to several other diseases such as cancer, diabetes, etc. Visceral adiposity is one of the major factors that play a role in the development of insulin resistance. Obesity causes a chronic low-grade inflammation in the tissues that further increases the chances of developing diabetes. Several pathways have been associated with the development of diabetes due to inflammation caused by obesity. The Wnt pathway is one such candidate pathway that is found to have a controlling effect on the development of insulin resistance. Moreover, the pathway has also been linked to obesity and inflammation. This review aims to find a connection between obesity, inflammation, and diabetes by taking the wnt pathway as the connecting link.

Diagnostic accuracy of the Xpert MTB/RIF assay for tuberculous pericarditis: A systematic review and meta-analysis

Objective

The purpose of this study was to evaluate the diagnostic efficacy of Xpert MTB/RIF for tuberculous pericarditis (TBP).

Methods

We searched relevant databases for Xpert MTB/RIF for TBP diagnosis until April 2021 and screened eligible studies for study inclusion. We evaluated the effectiveness of Xpert MTB/RIF when the composite reference standard (CRS) and mycobacterial culture were the gold standards, respectively. We performed meta-analyses using a bivariate random-effects model, and when the heterogeneity was obvious, the source of heterogeneity was further discussed.

Results

We included seven independent studies comparing Xpert MTB/RIF with the CRS and six studies comparing it with culture. The pooled sensitivity, specificity, and area under the curve of Xpert MTB/RIF were 65% (95% confidence interval, 59–72%), 99% (97–100%), and 0.99 (0.97–0.99) as compared with the CRS, respectively, and 75% (53–88%), 99% (90–100%), and 0.94 (0.92–0.96) as compared with culture, respectively. There was no significant heterogeneity between studies when CRS was the gold standard, whereas heterogeneity was evident when culture was the gold standard.

Conclusions

The sensitivity of Xpert MTB/RIF for diagnosing TBP was moderate and the specificity was good; thus, Xpert MTB/RIF can be used in the initial diagnosis of TBP.

Diagnostic accuracy of the Xpert MTB/RIF assay for tuberculous pericarditis: A protocol of systematic review and meta-analysis

BACKGROUND

Tuberculous pericarditis (TBP) can lead to serious consequences. Early diagnosis and treatment are very important for TBP, but early diagnosis is still very challenging. This study aims to evaluate the diagnostic accuracy of Xpert MTB/RIF for TBP using meta-analysis method.

METHODS

We will search Embase, PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and the Wanfang database for researches assessing the diagnostic accuracy of Xpert MTB/RIF for TBP until April 2021. Any types of study design with full text will be selected and included. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool will be used to assess the risk of bias. We will use version 15.0 of the STATA software with the midas command packages to carry out meta-analyses.

RESULTS

Evidence for diagnostic accuracy of Xpert MTB/RIF for TBP will be provided through the study, and this protocol will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide evidence of Xpert MTB/RIF for TBP.

Impact of Intermediate Hyperglycemia and Diabetes on Immune Dysfunction in Tuberculosis

BACKGROUND

People with diabetes have an increased risk of developing active tuberculosis (TB) and are more likely to have poor TB-treatment outcomes, which may impact on control of TB as the prevalence of diabetes is increasing worldwide. Blood transcriptomes are altered in patients with active TB relative to healthy individuals. The effects of diabetes and intermediate hyperglycemia (IH) on this transcriptomic signature were investigated to enhance understanding of immunological susceptibility in diabetes-TB comorbidity.

METHODS

Whole blood samples were collected from active TB patients with diabetes (glycated hemoglobin [HbA1c] ≥6.5%) or IH (HbA1c = 5.7% to <6.5%), TB-only patients, and healthy controls in 4 countries: South Africa, Romania, Indonesia, and Peru. Differential blood gene expression was determined by RNA-seq (n = 249).

RESULTS

Diabetes increased the magnitude of gene expression change in the host transcriptome in TB, notably showing an increase in genes associated with innate inflammatory and decrease in adaptive immune responses. Strikingly, patients with IH and TB exhibited blood transcriptomes much more similar to patients with diabetes-TB than to patients with only TB. Both diabetes-TB and IH-TB patients had a decreased type I interferon response relative to TB-only patients.

CONCLUSIONS

Comorbidity in individuals with both TB and diabetes is associated with altered transcriptomes, with an expected enhanced inflammation in the presence of both conditions, but also reduced type I interferon responses in comorbid patients, suggesting an unexpected uncoupling of the TB transcriptome phenotype. These immunological dysfunctions are also present in individuals with IH, showing that altered immunity to TB may also be present in this group. The TB disease outcomes in individuals with IH diagnosed with TB should be investigated further.

Effect of diabetes mellitus on TB drug concentrations in Tanzanian patients

BACKGROUND

Diabetes mellitus (DM) is associated with poor TB treatment outcome. Previous studies examining the effect of DM on TB drug concentrations yielded conflicting results. No studies have been conducted to date in an African population.

OBJECTIVES

To compare exposure to TB drugs in Tanzanian TB patients with and without DM.

PATIENTS AND METHODS

A prospective pharmacokinetic study was performed among 20 diabetic and 20 non-diabetic Tanzanian TB patients during the intensive phase of TB treatment. Plasma pharmacokinetic parameters of isoniazid, rifampicin, pyrazinamide and ethambutol were compared using an independent-sample t-test on log-transformed data. Multiple linear regression analysis was performed to assess the effects of DM, gender, age, weight, HIV status and acetylator status on exposure to TB drugs.

RESULTS

A trend was shown for 25% lower total exposure (AUC0-24) to rifampicin among diabetics versus non-diabetics (29.9 versus 39.9 mg·h/L, P=0.052). The AUC0-24 and peak concentration (Cmax) of isoniazid were also lower in diabetic TB patients (5.4 versus 10.6 mg·h/L, P=0.015 and 1.6 versus 2.8 mg/L, P=0.013). Pyrazinamide AUC0-24 and Cmax values were non-significantly lower among diabetics (P=0.08 and 0.09). In multivariate analyses, DM remained an independent predictor of exposure to isoniazid and rifampicin, next to acetylator status for isoniazid.

CONCLUSIONS

There is a need for individualized dosing of isoniazid and rifampicin based on plasma concentration measurements (therapeutic drug monitoring) and for clinical trials on higher doses of these TB drugs in patients with TB and DM.

Hepatocytic transcriptional signatures predict comparative drug interaction potential of rifamycin antibiotics

Current strategies to treat tuberculosis (TB) and co-morbidities involve multidrug combination therapies. Rifamycin antibiotics are a key component of TB therapy and a common source of drug–drug interactions (DDIs) due to induction of drug metabolizing enzymes (DMEs). Management of rifamycin DDIs are complex, particularly in patients with co-morbidities, and differences in DDI potential between rifamycin antibiotics are not well established. DME profiles induced in response to tuberculosis antibiotics (rifampin, rifabutin and rifapentine) were compared in primary human hepatocytes. We identified rifamycin induced DMEs, cytochrome P450 (CYP) 2C8/3A4/3A5, SULT2A, and UGT1A4/1A5 and predicted lower DDIs of rifapentine with 58 clinical drugs used to treat co-morbidities in TB patients. Transcriptional networks and upstream regulator analyses showed FOXA3, HNF4α, NR1I2, NR1I3, NR3C1 and RXRα as key transcriptional regulators of rifamycin induced DMEs. Our study findings are an important resource to design effective medication regimens to treat common co-conditions in TB patients.

CD11cHi monocyte-derived macrophages are a major cellular compartment infected by Mycobacterium tuberculosis

During tuberculosis, lung myeloid cells have two opposing roles: they are an intracellular niche occupied by Mycobacterium tuberculosis, and they restrict bacterial replication. Lung myeloid cells from mice infected with yellow-fluorescent protein expressing M. tuberculosis were analyzed by flow cytometry and transcriptional profiling to identify the cell types infected and their response to infection. CD14, CD38, and Abca1 were expressed more highly by infected alveolar macrophages and CD11cHi monocyte-derived cells compared to uninfected cells. CD14, CD38, and Abca1 "triple positive" (TP) cells had not only the highest infection rates and bacterial loads, but also a strong interferon-γ signature and nitric oxide synthetase-2 production indicating recognition by T cells. Despite evidence of T cell recognition and appropriate activation, these TP macrophages are a cellular compartment occupied by M. tuberculosis long-term. Defining the niche where M. tuberculosis resists elimination promises to provide insight into why inducing sterilizing immunity is a formidable challenge.

Metformin Alters Human Host Responses to Mycobacterium tuberculosis in Healthy Subjects

BACKGROUND

Metformin, the most widely administered diabetes drug, has been proposed as a candidate adjunctive host-directed therapy for tuberculosis, but little is known about its effects on human host responses to Mycobacterium tuberculosis.

METHODS

We investigated in vitro and in vivo effects of metformin in humans.

RESULTS

Metformin added to peripheral blood mononuclear cells from healthy volunteers enhanced in vitro cellular metabolism while inhibiting the mammalian target of rapamycin targets p70S6K and 4EBP1, with decreased cytokine production and cellular proliferation and increased phagocytosis activity. Metformin administered to healthy human volunteers led to significant downregulation of genes involved in oxidative phosphorylation, mammalian target of rapamycin signaling, and type I interferon response pathways, particularly following stimulation with M. tuberculosis, and upregulation of genes involved in phagocytosis and reactive oxygen species production was increased. These in vivo effects were accompanied by a metformin-induced shift in myeloid cells from classical to nonclassical monocytes. At a functional level, metformin lowered ex vivo production of tumor necrosis factor α, interferon γ, and interleukin 1β but increased phagocytosis activity and reactive oxygen species production.

CONCLUSION

Metformin has a range of potentially beneficial effects on cellular metabolism, immune function, and gene transcription involved in innate host responses to M. tuberculosis.

Drug resistance of previously treated tuberculosis patients with diabetes mellitus in Shandong, China

BACKGROUND

Although the association between diabetes mellitus (DM) and tuberculosis (TB) has been well-documented for centuries, evidence of the link between diabetes and drug resistance among previously treated TB patients remains limited and inconsistent.

METHODS

An observational study was performed that involved 1791 retreated TB-no DM patients (refers to TB cases without diabetes) and 93 retreated TB-DM patients (refers to TB cases with diabetes) in Shandong, China from 2004 to 2017. Baseline data including demographic and clinical characteristics, drug susceptibility test (DST) results, and diabetes status were collected. Categorical baseline characteristics were compared by Fisher's exact or Pearson Chi-square test. Univariable analysis and multivariable logistic models were used to estimate the association between diabetes and different drug resistance profiles.

RESULTS

Retreated TB-DM patients have a higher rate of drug resistance than TB-no DM patients (34.41% vs 25.00%, P < 0.01). Diabetes co-morbidity was significantly associated with any drug-resistant tuberculosis (DR-TB, odds ratio (OR):1.56, 95% confidence interval (CI): 1.01-2.43), multidrug resistant tuberculosis (MDR-TB, OR: 2.48, 95%CI:1.39-4.41; adjusted OR (aOR):2.94, 95%CI:1.57-5.48), isoniazid-related resistance (OR:1.71, 95%CI:1.04-2.81), rifampin-related resistance (OR:2.56, 0.54, 95%CI: 1.54-4.26; aOR:2.69, 95%CI:1.524-4.74), isoniazid + rifampin resistance (OR: 3.55, 95%CI:1.33-9.44; aOR:4.13, 95%CI:1.46-11.66), any resistance to isoniazid + streptomycin (OR:2.34, 95%CI:1.41-3.89; aOR:2.22, 95%CI:1.26-3.94), and any resistance to rifampin + isoniazid (OR:2.48, 95%CI:1.39-4.41; aOR:2.94, 95%CI: 1.57-5.48), compared with pan susceptible TB cases, P < 0.05.

CONCLUSIONS

The risk of acquired drug resistance increased significantly among retreated TB-DM patients compared with retreated TB-no DM patients, underlining the necessity of more interventions during the clinical management of TB-DM cases.

Type 2 Diabetes and its Impact on the Immune System

INTRODUCTION

Type 2 Diabetes (T2D) is a major health problem worldwide. This metabolic disease is indicated by high blood glucose levels due to insufficient insulin production by the pancreas. An inflammatory response occurs as a result of the immune response to high blood glucose levels as well as the presence of inflammatory mediators produced by adipocytes and macrophages in fat tissue. This low and chronic inflammation damages the pancreatic beta cells and leads to insufficient insulin production, which results in hyperglycemia. Hyperglycemia in diabetes is thought to cause dysfunction of the immune response, which fails to control the spread of invading pathogens in diabetic subjects. Therefore, diabetic subjects are known to more susceptible to infections. The increased prevalence of T2D will increase the incidence of infectious diseases and related comorbidities.

OBJECTIVE

This review provides an overview of the immunological aspect of T2D and the possible mechanisms that result in increased infections in diabetics.

CONCLUSION

A better understanding of how immune dysfunctions occur during hyperglycemia can lead to novel treatments and preventions for infectious diseases and T2D comorbidities, thus improving the outcome of infectious disease treatment in T2D patients.

[New vaccines against tuberculosis]

With about 10 million active disease cases and 1.5 million deaths in 2018, tuberculosis (TB) remains one of the most threatening infectious diseases. Yet, the World Health Organization (WHO) aims to reduce morbidity and mortality by 90 and 95%, respectively, between 2015 and 2035. Although diagnostics, therapeutics, and a vaccine are available, it is beyond doubt that better intervention measures are needed to accomplish this ambitious goal. The vaccine bacille Calmette-Guérin (BCG) partially protects infants against TB, but it is virtually ineffective against pulmonary TB in adolescents and adults. The efficacy of this vaccine, however, has not yet been fully exploited. In addition, new vaccine candidates are currently being assessed in clinical trials.Because a quarter of all people are latently infected with Mycobacterium tuberculosis (Mtb), new vaccines must be applied not only prior to infection (pre-exposure vaccination) but also after infection (postexposure vaccination). Prevention of infection, prevention of disease, and prevention of recurrence are currently assessed as clinical endpoints. Because protection against TB is primarily mediated by T lymphocytes, TB vaccine development focuses on protective T cell responses. Protein adjuvant formulations, viral vectors, and killed and live bacterial vaccines are currently being assessed in clinical trials. Moreover, therapeutic vaccination is clinically tested, notably in adjunct to canonical drug therapy to multiresistant TB. It is likely that a single vaccine cannot accomplish the various indications and that different vaccination strategies are required.

Tuberculosis in biologic users for rheumatic diseases: results from the South African Biologics Registry (SABIO)

Objectives

To evaluate the rate of tuberculosis (TB) in biologic users for rheumatic diseases in South Africa, the effectiveness of our latent TB infection (LTBI) programme, risk factors and outcome.

Methods

TB cases were collected from the South African Biologics Registry (SABIO), rheumatologists and pharmaceutical companies. Demographics, LTBI screening and treatment, biological and disease modifying antirheumatic drug (DMARD) therapies, TB diagnosis and outcomes were recorded.

Results

96 TB cases were collected from 1999 to June 2017: rheumatoid arthritis 55, ankylosing spondylitis 27, psoriatic arthritis 4, and juvenile inflammatory arthritis 10. The TB rate was 1240/100 000 person years for biologic users (n=96) versus the biologic naive cohort of 0/100 000 years with an incidence rate difference of 0.0124 (p<0.0001). 60/96 had pulmonary and 36/96 had extra-pulmonary TB. Reactivation TB occurred in 45/96 cases. TB occurred in all biologics licenced in South Africa, the majority in monoclonal inhibitors (1683/100 000 person years) compared with etanercept (861/100 000 person years) and non-tumour necrosis factor (TNF) inhibitors (681/100 000 person years). The incidence rate ratio for monoclonal inhibitors compared with etanercept was 1.96 (p=0.005) and 2.47 (p=0.002) compared with non-TNF inhibitors with no significant difference between non-TNF inhibitors and etanercept (p=0.336). From those (12.9%) who screened LTBI positive, 14 developed TB, while the majority (77) screened LTBI negative. Black race, male sex, younger age and residence in the Western Cape were statistical risk factors. Two drug resistant TB cases and six deaths occurred.

Conclusion

Reactivation and new onset TB is a significant risk for all biologics users in SA. Screening for LTBI is an imperative preventative strategy.

IL-22 produced by type 3 innate lymphoid cells (ILC3s) reduces the mortality of type 2 diabetes mellitus (T2DM) mice infected with Mycobacterium tuberculosis

Previously, we found that pathological immune responses enhance the mortality rate of Mycobacterium tuberculosis (Mtb)-infected mice with type 2 diabetes mellitus (T2DM). In the current study, we evaluated the role of the cytokine IL-22 (known to play a protective role in bacterial infections) and type 3 innate lymphoid cells (ILC3s) in regulating inflammation and mortality in Mtb-infected T2DM mice. IL-22 levels were significantly lower in Mtb-infected T2DM mice than in nondiabetic Mtb-infected mice. Similarly, serum IL-22 levels were significantly lower in tuberculosis (TB) patients with T2DM than in TB patients without T2DM. ILC3s were an important source of IL-22 in mice infected with Mtb, and recombinant IL-22 treatment or adoptive transfer of ILC3s prolonged the survival of Mtb-infected T2DM mice. Recombinant IL-22 treatment reduced serum insulin levels and improved lipid metabolism. Recombinant IL-22 treatment or ILC3 transfer prevented neutrophil accumulation near alveoli, inhibited neutrophil elastase 2 (ELA2) production and prevented epithelial cell damage, identifying a novel mechanism for IL-22 and ILC3-mediated inhibition of inflammation in T2DM mice infected with an intracellular pathogen. Our findings suggest that the IL-22 pathway may be a novel target for therapeutic intervention in T2DM patients with active TB disease.

Heterogeneity in the cytokine profile of tuberculosis - diabetes co-morbidity

Tuberculosis - diabetes (TB-DM) co-morbidity is characterized by heterogeneity in clinical and biochemical parameters between newly diagnosed diabetic individuals with TB (TB-NDM) and known diabetic individuals at incident TB (TB-KDM). However, the immunological profile underlying this heterogeneity is not explored. To identify the cytokine profiles in TB-NDM and TB-KDM individuals, we examined the plasma cytokine levels as well as TB-antigen stimulated levels of pro-inflammatory cytokines. TB-KDM individuals exhibit significantly higher levels of IFNγ, IL-2, TNFα, IL-17A, IL-1α, IL-1β and IL-6 in comparison to TB-NDM, TB alone and DM alone individuals. TB-NDM individuals are characterized by significantly lower levels of blood glucose and glycated hemoglobin in comparison to TB-KDM with both groups exhibiting a significant lowering of glycated hemoglobin levels at 6  months of anti-tuberculosis therapy (ATT). TB-NDM individuals are characterized by significantly diminished - unstimulated levels of IFNγ, IL-2, TNFα, IL-17A, IL-1α, IL-1β and IL-12 at pre-treatment, of IFNγ, IL-2 and IL-1α at 2  months of ATT and IL-2 at post-treatment in comparison to TB-KDM. TB-NDM individuals are also characterized by significantly diminished TB-antigen stimulated levels of IFNγ, IL-2, TNFα, IL-17A, IL-17F, IL-1α, IL-1β and/or IL-6 at pre-treatment and at 2  months of ATT and IFNγ, IL-2, IL-1α and IL-1β at post-treatment. In addition, TB-NDM individuals are characterized by significantly diminished mitogen - stimulated levels of IL-17F and IL-6 at pre-treatment and IL-6 alone at 6 months of ATT. Therefore, our data reveal considerable heterogeneity in the immunological underpinnings of TB-DM co-morbidity. Our data also suggest that TB-NDM exhibits a characteristic profile, which is both biochemically and immunologically distinct from TB-KDM.

Global Variations and Challenges With Tubercular Uveitis in the Collaborative Ocular Tuberculosis Study

Purpose

The aim of this study was to examine regional variation management practices and outcomes for tubercular uveitis (TBU).

Methods

In this retrospective multinational cohort study, patients from 25 international eye care centers diagnosed with TBU with a minimum follow-up of 1 year were included. The geographic variation in treatment outcomes on survival analysis in patients with TBU were analyzed. Treatment failure is defined as a persistence or recurrence of inflammation within 6 months of completing antitubercular therapy, the inability to taper oral corticosteroids to less than 10 mg/d or topical corticosteroid drops to less than 2 drops daily, and/or recalcitrant inflammation necessitating corticosteroid-sparing immunosuppressive therapy.

Results

Records of 945 patients (1485 eyes) with TBU were analyzed. The mean age was 41.3 ± 15.0 years (range, 4-90 years), with more males (52.9%, n = 500/945) and predominant Asian ethnicity (74.4%, n = 690/927). Most patients had no symptoms (92.0%, n = 655/712) or history (76.7%, n = 604/787) suggestive of pulmonary tuberculosis (TB). Some patients had evidence of inactive pulmonary TB on chest X-rays (26.9%, n = 189/702) or chest computed tomography (68.6%, n = 109/159). Patients with western geographic origin (log-rank = 6.47, P = 0.010), African or Hispanic ethnicity (log-rank = 19.9, P < 0.001), and positive immigrant status (log-rank = 4.89, P = 0.027) had poorer survival outcomes.

Conclusions

This is a first-ever multinational analysis of TBU that highlights regional differences in treatment outcomes for this elusive form of extrapulmonary TB. Our findings will help in the design of future collaborative studies together with internists to develop best practice guidelines for this early opportunity to address TB infection and strategies to target at-risk groups such as immigrants.

GeneXpert of stool versus gastric lavage fluid for the diagnosis of pulmonary tuberculosis in severely ill adults

PURPOSE

Stool is an alternative specimen matrix for tuberculosis (TB) tests, because Mycobacterium tuberculosis (MTB) can be swallowed and detected in the samples from digestive tract. We aimed to assess the performance of GeneXpert on stool and gastric lavage fluid (GALF) in diagnosing TB among patients with severe pulmonary TB.

METHODS

We enrolled adults with suspected pulmonary TB who were unable to produce sputum at visit between January 2016 and June 2018. Bacteriological samples consisted of one transtracheal aspirate sputum specimen, one stool specimen and/or one gastric lavage fluid specimen. Bacterial culture of transtracheal aspirate sputum provided the gold standard.

RESULTS

Of 65 individuals recruited for analysis, MGIT culture identified the presence of MTB in 32 samples. Overall, 29 of 32 stool samples from culture-positive cases were detected by the GeneXpert test, demonstrating a sensitivity of 90.6%. For GALF, 13 patients were detected as infected with MTB by GeneXpert, yielding a sensitivity of 56.5%. The statistical analysis revealed that GeneXpert showed significantly better sensitivity in detecting MTB from stool samples than GALF samples (P = 0.003). Among individuals with GeneXpert-positive stool, the percentage of individuals with comorbid diabetes was significantly higher than among individuals with GeneXpert-negative stool (19.4% vs. 2.9%, P = 0.034).

CONCLUSIONS

In conclusion, our data reveal that GeneXpert provides a higher detection rate on stool compared to GALF, indicating stool should be considered as an alternative for adult TB patients unable to produce sputum. Individuals with diabetes are more likely to have positive GeneXpert stool than nondiabetic individuals.

Immunometabolic Signatures Predict Risk of Progression to Active Tuberculosis and Disease Outcome

There remains a pressing need for biomarkers that can predict who will progress to active tuberculosis (TB) after exposure to Mycobacterium tuberculosis (MTB) bacterium. By analyzing cohorts of household contacts of TB index cases (HHCs) and a stringent non-human primate (NHP) challenge model, we evaluated whether integration of blood transcriptional profiling with serum metabolomic profiling can provide new understanding of disease processes and enable improved prediction of TB progression. Compared to either alone, the combined application of pre-existing transcriptome- and metabolome-based signatures more accurately predicted TB progression in the HHC cohorts and more accurately predicted disease severity in the NHPs. Pathway and data-driven correlation analyses of the integrated transcriptional and metabolomic datasets further identified novel immunometabolomic signatures significantly associated with TB progression in HHCs and NHPs, implicating cortisol, tryptophan, glutathione, and tRNA acylation networks. These results demonstrate the power of multi-omics analysis to provide new insights into complex disease processes.

"Wasting away": Diabetes, food insecurity, and medical insecurity in the Somali Region of Ethiopia

Most research on diabetes has taken place in cities or in high-income countries, even though most diabetes deaths occur in low and middle-income countries, and diabetes disproportionately affects the poor. This research, by contrast, investigates rising concerns about diabetes among Somalis in eastern Ethiopia--in communities where obesity is rare and people face chronic food insecurity, forced displacement, recurrent humanitarian crises, and lack of access to medical care. Findings presented in this article build on ethnographic research with Somalis in eastern Ethiopia since 2007, and include anthropometric and demographic data collection with Somali diabetes patients and select adult siblings of these patients (n = 108) plus in-depth ethnographic interviews with a subset of the diabetes patients, their siblings, and medical providers serving Somali communities (n = 29) in July-August 2018. Most Somali patients we spoke with shared symptoms of progressive weight loss, weakness, and loss of teeth--or what people called "wasting away"--even when complying with prescribed pharmaceutical regimens and/or insulin. Diabetes and "wasting away" were characterized by Somalis as humoral pathologies; but rather than a consequence of obesity or pathological weight gain, these were perceived to be a consequence of stress, trauma, anger, displacement, loss of healthy fatness, and lack of access to fresh and healthy food over their lifetimes. Somalis' simultaneous experiences of progressive nutritional wasting and adult-onset diabetes echo how "tropical diabetes" was defined and experienced for thousands of years prior to the development of effective early diagnostics and biomedical treatments. This analysis therefore suggests heterogeneity and overlaps within and between categories of "type 1" and "type 2 diabetes" in populations with differential exposures to stress, crisis, and poverty. Exposures to food insecurity and medical insecurity, in particular, are pathogenic, and shape diabetes patients' clinical presentations and prognoses, as well as local etiologies and patterns of disease.

Host Transcriptomics as a Tool to Identify Diagnostic and Mechanistic Immune Signatures of Tuberculosis

Tuberculosis (TB) is a major infectious disease worldwide, and is associated with several challenges for control and eradication. First, more accurate diagnostic tools that better represent the spectrum of infection states are required; in particular, identify the latent TB infected individuals with high risk of developing active TB. Second, we need to better understand, from a mechanistic point of view, why the immune system is unsuccessful in some cases for control and elimination of the pathogen. Host transcriptomics is a powerful approach to identify both diagnostic and mechanistic immune signatures of diseases. We have recently reported that optimal study design for these two purposes should be guided by different sets of criteria. Here, based on already published transcriptomics signatures of tuberculosis, we further develop these guidelines and identify additional factors to consider for obtaining diagnostic vs. mechanistic signatures in terms of cohorts, samples, data generation and analysis. Diagnostic studies should aim to identify small disease signatures with high discriminatory power across all affected populations, and against similar pathologies to TB. Specific focus should be made on improving the diagnosis of infected individuals at risk of developing active disease. Conversely, mechanistic studies should focus on tissues biopsies, immune relevant cell subsets, state of the art transcriptomic techniques and bioinformatics tools to understand the biological meaning of identified gene signatures that could facilitate therapeutic interventions. Finally, investigators should ensure their data are made publicly available along with complete annotations to facilitate metadata and cross-study analyses.

Kaposi's sarcoma-associated herpesvirus seropositivity is associated with type 2 diabetes mellitus: A case-control study in Xinjiang, China

OBJECTIVE

To assess the potential relationship between Kaposi's sarcoma-associated herpesvirus (KSHV) infection and type 2 diabetes mellitus (DM-2) in Xinjiang, China.

METHODS

A case-control study of consecutively included DM-2 patients and normal controls was conducted among the Uygur and Han populations in Xinjiang Uygur Autonomous Region, China. Blood samples were collected and KSHV seroprevalence, antibody titers, and viral load were investigated. Logistic regression analysis and multiple linear regression analysis were applied to explore determinants of the main outcome measures.

RESULTS

A total of 324 patients with DM-2 and 376 normal controls were included. The seroprevalence of KSHV was 49.1% (95% confidence interval (CI) 43.6-54.5%) for diabetic patients and 23.7% (95% CI 19.4-28.0%) for the control group. After adjusting for variables of ethnicity, sex, body mass index, occupation, educational level, marital status, age, and smoking and alcohol consumption habits, the association between DM-2 and KSHV infection still existed (odds ratio (OR) 2.94, 95% CI 2.05-4.22), and the risk of KSHV infection increased with glucose concentration (OR 1.35, 95% CI 1.21-1.51). KSHV was more likely to express both the latent and lytic antigens in diabetic patients (latent: OR 3.27, 95% CI 2.25-4.75; lytic: OR 3.99, 95% CI 2.68-5.93). Antibody titers and viral load increased in patients with higher blood glucose levels (p<0.001).

CONCLUSIONS

Patients with DM-2 have an elevated risk of KSHV infection. Both antibody titers and viral load increased with blood glucose levels.

IL-22: An Underestimated Player in Natural Resistance to Tuberculosis?

Approximately 10% of individuals latently infected with Mycobacterium tuberculosis (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring protective immunity from TB progression are not completely understood. IL-22 is produced by cells of the innate and adaptive immune system including innate lymphoid cells, and natural killer cells as well as T lymphocytes (Th1, Th17, and Th22) and binds to its cognate receptor, the IL-22R1, which is expressed on non-hematopoietic cells such as lung epithelial cells. However, recent studies suggest that Mtb induces expression of the IL-22R1 on infected macrophages and multiple studies have indicated a protective role of IL-22 in respiratory tract infections. Reduced concentrations of circulating IL-22 in active TB compared to latent TB and decreased percentages of Mtb-specific IL-22 producing T cells in TB patients compared to controls designate this cytokine as a key player in TB immunology. More recently, it has been shown that in type 2 diabetes (T2D) and TB co-morbidity serum IL-22 concentrations are further reduced compared to TB patients without co-morbidities. However, whether a causative link between low IL-22 and increased susceptibility to TB and disease severity of TB exists remains to be established. This review summarizes the contribution of IL-22, a potentially under-appreciated key player in natural resistance to TB, at the interface between the immune response to Mtb and the lung epithelium.

Glutathione as a Marker for Human Disease

Glutathione (GSH), often referred to as "the master antioxidant," participates not only in antioxidant defense systems, but many metabolic processes, and therefore its role cannot be overstated. GSH deficiency causes cellular risk for oxidative damage and thus as expected, GSH imbalance is observed in a wide range of pathological conditions including tuberculosis (TB), HIV, diabetes, cancer, and aging. Consequently, it is not surprising that GSH has attracted the attention of biological researchers and pharmacologists alike as a possible target for medical intervention. Here, we discuss the role GSH plays amongst these pathological conditions to illuminate how it can be used as a marker for human disease.

Diabetes is associated with increased prevalence of latent tuberculosis infection: Findings from the National Health and Nutrition Examination Survey, 2011-2012

AIMS

We aim to determine the association between prediabetes and diabetes with latent TB using National Health and Nutrition Examination Survey data.

METHODS

We performed a cross-sectional analysis of 2011-2012 National Health and Nutrition Examination Survey data. Participants ≥20 years were eligible. Diabetes was defined by glycated hemoglobin (HbA1c) as no diabetes (≤5.6% [38 mmol/mol]), prediabetes (5.7-6.4% [39-46 mmol/mol]), and diabetes (≥6.5% [48 mmol/mol]) combined with self-reported diabetes. Latent TB infection was defined by the QuantiFERON®-TB Gold In Tube (QFT-GIT) test. Adjusted odds ratios (aOR) of latent TB infection by diabetes status were calculated using logistic regression and accounted for the stratified probability sample.

RESULTS

Diabetes and QFT-GIT measurements were available for 4958 (89.2%) included participants. Prevalence of diabetes was 11.4% (95%CI 9.8-13.0%) and 22.1% (95%CI 20.5-23.8%) had prediabetes. Prevalence of latent TB infection was 5.9% (95%CI 4.9-7.0%). After adjusting for age, sex, smoking status, history of active TB, and foreign born status, the odds of latent TB infection were greater among adults with diabetes (aOR 1.90, 95%CI 1.15-3.14) compared to those without diabetes. The odds of latent TB in adults with prediabetes (aOR 1.15, 95%CI 0.90-1.47) was similar to those without diabetes.

CONCLUSIONS

Diabetes is associated with latent TB infection among adults in the United States, even after adjusting for confounding factors. Given diabetes increases the risk of active TB, patients with co-prevalent diabetes and latent TB may be targeted for latent TB treatment.

The Troika Host-Pathogen-Extrinsic Factors in Tuberculosis: Modulating Inflammation and Clinical Outcomes

The already enormous burden caused by tuberculosis (TB) will be further aggravated by the association of this disease with modern epidemics, as human immunodeficiency virus and diabetes. Furthermore, the increasingly aging population and the wider use of suppressive immune therapies hold the potential to enhance the incidence of TB. New preventive and therapeutic strategies based on recent advances on our understanding of TB are thus needed. In particular, understanding the intricate network of events modulating inflammation in TB will help to build more effective vaccines and host-directed therapies to stop TB. This review integrates the impact of host, pathogen, and extrinsic factors on inflammation and the almost scientifically unexplored complexity emerging from the interactions between these three factors. We highlight the exciting data showing a contribution of this troika for the clinical outcome of TB and the need of incorporating it when developing novel strategies to rewire the immune response in TB.

Patients with type 1 diabetes mellitus have impaired IL-1β production in response to Mycobacterium tuberculosis

Patients with diabetes mellitus have an increased risk of developing tuberculosis. Although the underlying mechanism is unclear, evidence suggests a role for chronic hyperglycaemia. We examined the influence of hyperglycaemia on Mycobacterium tuberculosis-induced cytokine responses in patients with type 1 diabetes mellitus (T1D). Peripheral blood mononuclear cells (PBMCs) from 24 male T1D patients with sub-optimal glucose control [HbA1c > 7.0% (53 mmol/L)] and from 24 age-matched male healthy controls were stimulated with M. tuberculosis lysate. Cytokine analysis, assessment of aerobic glycolysis, receptor recognition and serum cross-over experiments were performed to explore the mechanistic differences. PBMCs from T1D patients produced less bioactive interleukin (IL)-1β in response to M. tuberculosis. IL-6 and interferon (IFN)-γ production trended towards a decrease, whilst other cytokines such as tumour necrosis factor (TNF)-α, IL-17 and IL-1Ra were normal. The decrease in cytokine production was not correlated to HbA1c or plasma glucose levels. Cross-over serum experiments did not alter the cytokine profile of T1D or control patients, arguing for an intrinsic cellular defect. Cellular metabolism and the expression of M. tuberculosis-related pattern recognition receptors (PRRs) such as TLR2, TLR4 and NOD2 did not differ between T1D patients and healthy controls. Compared to matched controls, T1D patients have a reduced capacity to produce pro-inflammatory cytokines in response to M. tuberculosis. The impaired IL-1β production in T1D patients may contribute to the increased susceptibility to tuberculosis. This effect appears not to be related to prevailing glucose levels but to an intrinsic cellular deficit.

Association between Mycobacterium tuberculosis lineage and site of disease in Florida, 2009-2015

BACKGROUND

Mycobacterium tuberculosis is characterized into four global lineages with strong geographical restriction. To date one study in the United States has investigated M. tuberculosis lineage association with tuberculosis (TB) disease presentation (extra-pulmonary versus pulmonary). We update this analysis using recent (2009-2015) data from the State of Florida to measure lineage association with pulmonary TB, the infectious form of the disease.

METHODS

M. tuberculosis lineage was assigned based on the spacer oligonucleotide typing (spoligotyping) patterns. TB disease site was defined as exclusively pulmonary or extra-pulmonary. We used ORs to measure the association between M. tuberculosis lineages and pulmonary compared to extra-pulmonary TB. The final multivariable model was adjusted for patient socio-demographics, HIV and diabetes status.

RESULTS

We analyzed 3061 cases, 83.4% were infected with a Euro-American lineage, 8.4% Indo-Oceanic and 8.2% East-Asian lineage. The majority of the cases (86.0%) were exclusively pulmonary. Compared to the Indo-Oceanic lineage, infection with a Euro-American (AOR=1.87, 95% CI: 1.21, 2.91) or an East-Asian (AOR=2.11, 95% CI: 1.27, 3.50) lineage favored pulmonary disease compared to extra-pulmonary. In a sub-analysis among pulmonary cases, strain lineage was not associated with sputum smear positive status, indicating that the observed association with pulmonary disease is independent of host contagiousness.

CONCLUSION

As an obligate pathogen, M. tuberculosis' fitness is directly correlated to its transmission potential. In this analysis, we show that M. tuberculosis lineage is associated with pulmonary disease presentation. This association may explain the predominance in a region of certain lineages compared to others.

Immune characterization of the HBHA-specific response in Mycobacterium tuberculosis-infected patients with or without HIV infection

Introduction

RD1-based Interferon-γ Release Assays (IGRAs) cannot distinguish latent from active tuberculosis (TB) disease. Conversely, a positive response to heparin-binding haemagglutinin (HBHA)-based IGRAs, among TB-infected subjects, correlates with Mycobacterium tuberculosis (Mtb) containment and low risk of TB progression. The aim of this study was to characterize HBHA-immune responses in HIV-infected and uninfected subjects with active TB or latent TB infection (LTBI).

Methods

49 subjects were prospectively enrolled: 22 HIV-uninfected (13 TB, 9 LTBI) and 27 HIV-infected (12 HIV-TB, 15 HIV-LTBI). Whole blood and peripheral blood mononuclear cells were stimulated with HBHA and RD1 antigens. Interferon (IFN)γ release was evaluated by ELISA whereas cytokine profile [IFNγ, tumor necrosis (TNF)α, interleukin (IL)2] and phenotype (CD45RA, CCR7) by flow cytometry.

Results

Among LTBI individuals, HBHA stimulation induced IFNγ release in all the HIV-uninfected, while, only 4/15 HIV-infected responded. Within the active TB, only 5/13 HIV-uninfected and 1/12 HIV-TB patients responded. Interestingly, by cytometry we showed that CD4⁺ T-cells response to HBHA was significantly impaired in the HIV-infected subjects with TB or LTBI compared to the HIV-uninfected subjects. The phenotype of HBHA-specific CD4 T-cells showed a predominantly central memory (CM) and effector memory (EM) phenotype without differences among the groups. Differently, HBHA-specific CD8⁺ T-cells, showed mainly a CM and naïve phenotype in LTBI group while TB, HIV-LTBI and HIV-TB groups were characterized by EM or terminally differentiated phenotypes. Interestingly, differently than what observed for RD1, the cytokine profile of HBHA-specific T-cells evaluated by cytometry showed that the CD4⁺ T-cells were mostly monofunctional. Conversely, CD8-specific T-cells were mostly monofunctional for both HBHA and RD1 stimulations.

Conclusions

These results characterize the impact of HIV infection in CD4- and CD8-specific response to HBHA in both LTBI and TB patients. HIV infection impairs the CD4 response to HBHA and likely this may lead to an impairment of TB control.

Diabetes and Tuberculosis

The increase in type 2 diabetes mellitus (DM) patients in countries where tuberculosis (TB) is also endemic has led to the reemerging importance of DM as a risk factor for TB. DM causes a 3-fold increase in TB risk and a 2-fold increase in adverse TB treatment outcomes. Given the sheer numbers of DM patients worldwide, there are now more TB patients with TB-DM comorbidity than TB-HIV coinfection. There is an urgent need to implement strategies for TB prevention and control among the millions of DM patients exposed to Mycobacterium tuberculosis. This chapter summarizes the current epidemiological, clinical, and immunological knowledge on TB and DM and their clinical and public health implications. These include the underlying mechanisms for TB risk in DM patients and their clinical and sociodemographic characteristics that distinguish them from TB patients without DM. TB-DM comorbidity is posing a new challenge for integrating the short-term care for TB with the long-term care for DM, particularly in low- and middle-income countries.

Tuberculosis and diabetes in Nigerian patients with and without HIV

BACKGROUND

Type 2 diabetes mellitus (DM) and HIV increase the risk of tuberculosis (TB). The frequency of DM among patients with TB with and without HIV is poorly documented in many low- and middle-income countries.

METHODS

This was a cross-sectional hospital-based study performed in Abuja, Nigeria. Adults with presumptive TB were screened consecutively. Sputum culture was used for TB screening and blood was used for HIV screening, as well as fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c) assessment for the diagnosis of DM. HbA1c was measured using the D-10 Haemoglobin Testing System and a point-of-care test (A1C Now+ system) for comparison. Patients were classified as having DM or pre-diabetes using the D-10 reference test.

RESULTS

Four hundred and ten individuals had TB culture, FPG, and HbA1c results. Participants had a mean (±standard deviation) age of 37.8±12.6 years and 217 (54.8%) were male. One hundred and thirteen (27.6%) patients were culture-positive, 62 (15.1%) had DM, and 46 (11.2%) had pre-diabetes. One hundred and eighty-four (53.3%) participants were HIV-positive and 95 (51.6%) were on antiretroviral therapy (ART). Patients with pre-diabetes and DM were more likely to have TB (odds ratio (OR) 1.94, 95% confidence interval (CI) 0.01-3.74, and OR 2.39, 95% CI 1.35-4.24, respectively). After adjustment for HIV, age, and sex, only DM was statistically associated with TB (adjusted OR (AOR) 3.10, 95% CI 1.62-5.94). HIV-negative patients with DM had a higher risk of TB (AOR 4.32, 95% CI 1.57-11.92) than HIV-positive patients with DM (AOR 3.31, 95% CI 1.29-8.54), but the difference was not statistically significant. A1C Now+ HbA1c measurements correlated poorly with the D-10 HbA1c reference test.

CONCLUSION

A high proportion of patients in Abuja have markers of DM and pre-diabetes at the time of TB diagnosis.

Differences in IgG responses against infection phase related Mycobacterium tuberculosis (Mtb) specific antigens in individuals exposed or not to Mtb correlate with control of TB infection and progression

Tuberculosis (TB) occurs in only 3-10% of Mycobacterium tuberculosis (Mtb) infected individuals, suggesting that natural immunity can contain Mtb infection, although this remains poorly understood. Next to T-cells, a potentially protective role for B-cells and antibodies has emerged recently. However, the Mtb antigens involved remain ill-defined. Here, we investigated in a TB-endemic setting IgG levels against 15 Mtb antigens, representing various phases of Mtb infection and known to be potent human T-cell antigens. IgG levels against ESAT6/CFP10, Rv0440, Rv0867c, Rv1737c, Rv2029c, Rv2215, Rv2389c, Rv3616c and Mtb purified protein derivative (PPD) were higher in TB patients than in endemic and non-endemic controls. The only exception was Rv1733c that was preferentially recognized by antibodies from endemic controls compared to TB patients and non-endemic controls, suggesting a potential correlation with control of TB infection and progression. In patients, IgG levels against Ag85B and Rv2029c correlated with Mtb loads, while immunoglobulins against Rv0440 differed between genders. Our results support the potential role of certain Mtb antigen-(Rv1733c) specific antibodies in the control of TB infection and progression, while other Mtb antigen-specific antibodies correlate with TB disease activity and bacillary loads. The findings for Rv1733c agree with previous T-cell results and have implications for including antibody-mediated immunity in designing new strategies to control TB.

The global diabetes epidemic: what does it mean for infectious diseases in tropical countries?

Tropical countries are experiencing a substantial rise in type 2 diabetes, which is often undiagnosed or poorly controlled. Since diabetes is a risk factor for many infectious diseases, this increase probably adds to the large infectious disease burden in tropical countries. We reviewed the literature to investigate the interface between diabetes and infections in tropical countries, including the WHO-defined neglected tropical diseases. Although solid data are sparse, patients with diabetes living in tropical countries most likely face increased risks of common and health-care-associated infections, as well as infected foot ulcers, which often lead to amputation. There is strong evidence that diabetes increases the severity of some endemic infections such as tuberculosis, melioidosis, and dengue virus infection. Some HIV and antiparasitic drugs might induce diabetes, whereas helminth infections appear to afford some protection against future diabetes. But there are no or very scarce data for most tropical infections and for possible biological mechanisms underlying associations with diabetes. The rise in diabetes and other non-communicable diseases puts a heavy toll on health systems in tropical countries. On the other hand, complications common to both diabetes and some tropical infections might provide an opportunity for shared services-for example, for eye health (trachoma and onchocerciasis), ulcer care (leprosy), or renal support (schistosomiasis). More research about the interaction of diabetes and infections in tropical countries is needed, and the infectious disease burden in these countries is another reason to step up global efforts to improve prevention and care for diabetes.

Association between enteric protozoan parasites and gastrointestinal illness among HIV- and tuberculosis-infected individuals in the Chowke district, southern Mozambique

Human immune deficiency virus (HIV) and tuberculosis (TB) infections remain major public health issues globally, particularly in sub-Saharan Africa. Impairment of both cell-mediated and humoral immunity by HIV and/or TB infections may limit the host's defences against other pathogens, including the diarrheagenic protozoan Cryptosporidium spp., Giardia intestinalis, and Entamoeba histolytica. During September-December 2015 a cross-sectional study was conducted to assess the prevalence and molecular diversity of these enteric parasites among HIV- and/or TB-infected patients at a medical reference centre in Chowke district, southern Mozambique. A total of 99 stool specimens were initially screened by direct microscopy and further confirmed and characterised by molecular methods. DNA sequence analyses of the genes encoding the small subunit ribosomal RNA and the 60-kDa glycoprotein were used for the typing and sub-typing of Cryptosporidium isolates, respectively. G. intestinalis-positive isolates by real-time PCR were subsequently typed at the glutamate dehydrogenase locus. Differential diagnosis of E. histolytica/dispar was achieved by real-time PCR. G. intestinalis (8.1%) was the enteric protozoan more frequently detected, followed by Cryptosporidium spp. (7.1%), and Entamoeba histolytica/dispar (6.1%). Two HIV-infected (but not TB-infected) patients harbour G. intestinalis and Cryptosporidium spp. co-infections. Two (29%) G. intestinalis isolates were successfully characterised, revealing the presence of known AII and novel BIV genotypes. Four (57%) Cryptosporidium isolates were unmistakeable assigned to C. hominis, identifying two (IbA10G2 and IdA22) sub-types. Cryptosporidium infections were not associated to diarrhoea in HIV-positive patients, probably because improved immune function in the affected individuals due to antiretroviral therapy. G. intestinalis was considered a non-opportunistic pathogen, whereas the presence of E. histolytica could not be confirmed by molecular methods. Based on their common presence in the studied clinical population, we recommend the effective diagnosis and treatment of these enteropathogens for improving the management of HIV and TB patients.