Profiling leucocyte subsets in tuberculosis-diabetes co-morbidity

The impact of diabetes mellitus on tuberculosis recurrence in Eastern China: a retrospective cohort study

BACKGROUND

The comorbidity of tuberculosis (TB) and diabetes mellitus (DM) is a significant global public health issue. This study aims to explore the recurrence risk and related factors of active pulmonary TB, specifically focusing on the impact of DM.

METHODS

A retrospective cohort study was conducted in Lianyungang City, Jiangsu Province, Eastern China by recruiting 12,509 individuals with newly diagnosed pulmonary TB between 2011 and 2019. The Cox proportional hazards models were performed to identify risk factors of recurrence and assess the association between DM and recurrence. The hazard ratio (HR) and 95% confidence interval (CI) were used to estimate the strength of the association.

RESULTS

After a median follow-up period of 5.46 years, we observed 439 recurrent cases (incident recurrence rate: 6.62 per 1000 person-years). Males (HR: 1.30, 95% CI: 1.03-1.64), patients aged ≥ 60 years (HR: 1.39, 95% CI: 1.15-1.70), DM (HR: 2.40, 95% CI: 1.68-3.45), and etiologic positivity in the initial episode (HR: 2.42, 95% CI: 2.00-2.92) had a significantly increased risk of recurrence.

CONCLUSIONS

Recurrence of pulmonary TB patients who have completed treatment, especially those who also suffer from DM, should be a concern. Enhanced follow-up and targeted surveillance of these high-risk groups are needed.

Elucidating the Immune Response to SARS-CoV-2: Natural Infection versus Covaxin/Covishield Vaccination in a South Indian Population

A natural infection or a vaccination can initially prime the immune system to form immunological memory. The immunity engendered by vaccination against COVID-19 versus natural infection with SARS-CoV-2 has not been well studied in the Indian population. In this study, we compared the immunity conferred by COVID-19 vaccines to naturally acquired immunity to SARS-CoV-2 in a South Indian population. We examined binding and neutralizing antibody (NAb) levels against the ancestral and variant lineages and assessed the ex vivo cellular parameters of memory T cells, memory B cells, and monocytes and finally measured the circulating cytokine response. COVID-19 vaccination stimulates heightened levels of IgG antibodies against the original strain of SARS-CoV-2, as well as increased binding to the spike protein and neutralizing antibody levels. This enhanced response extends to variant lineages such as B.1.617.2 (Delta, India), B.1.1.529 (Omicron, India), B.1.351 (Beta, South Africa), and B.1.1.7 (Alpha, UK). COVID-19 vaccination differs from SARS-CoV-2 infection by having increased frequencies of classical memory B cells, activated memory B and plasma cells, CD4/CD8 T cells of effector memory, effector cells, stem cell-like memory T cells, and classical and intermediate monocytes and diminished frequencies of CD4/CD8 T cells of central memory and non-classical monocytes in vaccinated individuals in comparison to those with natural infection. Thus, COVID-19 vaccination is characterized by enhanced humoral responses and robust activation of innate and memory T cell responses in comparison to natural infection in a South Indian population.

The potential association between metabolic disorders and pulmonary tuberculosis: a Mendelian randomization study

BACKGROUND

Metabolic disorders (MetDs) have been demonstrated to be closely linked to numerous diseases. However, the precise association between MetDs and pulmonary tuberculosis (PTB) remains poorly understood.

METHOD

Summary statistics for exposure and outcomes from genome-wide association studies (GWASs) for exposures and outcomes were obtained from the BioBank Japan Project (BBJ) Gene-exposure dataset. The 14 clinical factors were categorized into three groups: metabolic laboratory markers, blood pressure, and the MetS diagnostic factors. The causal relationship between metabolic factors and PTB were analyzed using two-sample Mendelian Randomization (MR). Additionally, the direct effects on the risk of PTB were investigated through multivariable MR. The primary method employed was the inverse variance-weighted (IVW) model. The sensitivity of this MR analysis was evaluated using MR-Egger regression and the MR-PRESSO global test.

RESULTS

According to the two-sample MR, HDL-C, HbA1c, TP, and DM were positively correlated with the incidence of active TB. According to the multivariable MR, HDL-C (IVW: OR 2.798, 95% CI 1.484-5.274, P = 0.001), LDL (IVW: OR 4.027, 95% CI 1.140-14.219, P = 0.03) and TG (IVW: OR 2.548, 95% CI 1.269-5.115, P = 0.009) were positively correlated with the occurrence of PTB. TC (OR 0.131, 95% CI 0.028-0.607, P = 0.009) was negatively correlated with the occurrence of PTB. We selected BMI, DM, HDL-C, SBP, and TG as the diagnostic factors for metabolic syndrome. DM (IVW, OR 1.219, 95% CI 1.040-1.429 P = 0.014) and HDL-C (IVW, OR 1.380, 95% CI 1.035-1.841, P = 0.028) were directly correlated with the occurrence of PTB.

CONCLUSIONS

This MR study demonstrated that metabolic disorders, mainly hyperglycemia, and dyslipidemia, are associated with the incidence of active pulmonary tuberculosis.

Pulmonary tuberculosis and diabetes mellitus: Epidemiology, pathogenesis and therapeutic management (Review)

The dual burden of pulmonary tuberculosis (PTB) and diabetes mellitus (DM) is a major global public health concern. There is increasing evidence to indicate an association between PTB and DM. DM is associated with immune dysfunction and altered immune components. Hyperglycemia weakens the innate immune response by affecting the function of macrophages, dendritic cells, neutrophils, and natural killer cells, and also disrupts the adaptive immune response, thus promoting the susceptibility of PTB in patients with DM. Antituberculosis drugs often cause the impairment of liver and kidney function in patients with PTB, and the infection with Mycobacterium tuberculosis weaken pancreatic endocrine function by causing islet cell amyloidosis, which disrupts glucose metabolism and thus increases the risk of developing DM in patients with PTB. The present review discusses the association between PTB and DM from the perspective of epidemiology, pathogenesis, and treatment management. The present review aims to provide information for the rational formulation of treatment strategies for patients with PTB-DM.

Unique cellular immune signatures of multisystem inflammatory syndrome in children

The clinical presentation of MIS-C overlaps with other infectious/non-infectious diseases such as acute COVID-19, Kawasaki disease, acute dengue, enteric fever, and systemic lupus erythematosus. We examined the ex-vivo cellular parameters with the aim of distinguishing MIS-C from other syndromes with overlapping clinical presentations. MIS-C children differed from children with non-MIS-C conditions by having increased numbers of naïve CD8+ T cells, naïve, immature and atypical memory B cells and diminished numbers of transitional memory, stem cell memory, central and effector memory CD4+ and CD8+ T cells, classical, activated memory B and plasma cells and monocyte (intermediate and non-classical) and dendritic cell (plasmacytoid and myeloid) subsets. All of the above alterations were significantly reversed at 6-9 months post-recovery in MIS-C. Thus, MIS-C is characterized by a distinct cellular signature that distinguishes it from other syndromes with overlapping clinical presentations. Trial Registration: ClinicalTrials.gov clinicaltrial.gov. No: NCT04844242.

The Association Between Diabetes Mellitus and the Risk of Latent Tuberculosis Infection: A Systematic Review and Meta-Analysis

Background

The estimated global latent tuberculosis infection (LTBI) burden indicates a large reservoir of population at risk of developing active tuberculosis (TB). Previous studies suggested diabetes mellitus (DM) might associate with LTBI, though still controversial. We aimed to systematically assess the association between DM and LTBI.

Methods

We searched PubMed, Embase, Cochrane Library and Web of Science. Observational studies reporting the number of LTBI and non-LTBI individuals with and without DM were included. Random-effects or fixed-effects models were used to estimate the pooled effect by risk ratios (RRs) and odds ratios (ORs) and its 95% confidence interval (CI), using the original number of participants involved.

Results

20 studies involving 4,055,082 participants were included. The pooled effect showed a significant association between DM and LTBI (for cohort studies, RR = 1.62, 95% CI: 1.02-2.56; for cross-sectional studies, OR = 1.55, 95% CI: 1.30-1.84). The pooled OR was high in studies with healthcare workers (5.27, 95% CI: 1.52-8.20), refugees (2.88, 95% CI: 1.93-4.29), sample size of 1,000-5,000 (1.99, 95% CI: 1.49-2.66), and male participants accounted for less than 40% (2.28, 95% CI: 1.28-4.06). Prediabetes also associated with LTBI (OR = 1.36, 95% CI: 1.01-1.84).

Conclusion

The risk of LTBI was found to be a 60% increase in DM patients, compared with non-DM patients. LTBI screening among DM patients could be of vital importance. More studies are needed to explore appropriate strategies for targeted LTBI screening among DM patients.

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.

BCG vaccination induces enhanced frequencies of memory T cells and altered plasma levels of common γc cytokines in elderly individuals

BCG vaccination is known to induce innate immune memory, which confers protection against heterologous infections. However, the effect of BCG vaccination on the conventional adaptive immune cells subsets is not well characterized. We investigated the impact of BCG vaccination on the frequencies of T cell subsets and common gamma c (γc) cytokines in a group of healthy elderly individuals (age 60–80 years) at one month post vaccination as part of our clinical study to examine the effect of BCG on COVID-19. Our results demonstrate that BCG vaccination induced enhanced frequencies of central (p<0.0001) and effector memory (p<0.0001) CD4+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001), stem cell memory (p = 0.0001) CD4+ T cells and regulatory T cells. In addition, BCG vaccination induced enhanced frequencies of central (p = 0.0008), effector (p<0.0001) and terminal effector memory (p<0.0001) CD8+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001) and stem cell memory (p = 0.0034) CD8+T cells. BCG vaccination also induced enhanced plasma levels of IL-7 (p<0.0001) and IL-15 (p = 0.0020) but diminished levels of IL-2 (p = 0.0033) and IL-21 (p = 0.0020). Thus, BCG vaccination was associated with enhanced memory T cell subsets as well as memory enhancing γc cytokines in elderly individuals, suggesting its ability to induce non-specific adaptive immune responses.

Ex-vivo immunophenotyping and high dimensionality UMAP analysis of leucocyte subsets in tuberculous lymphadenitis

Tuberculous lymphadenitis (TBL) is defined by reduced proinflammatory cytokines and elevated CD4⁺, CD8⁺ T cells and decreased CD8⁺ cytotoxic markers. However, ex-vivo phenotyping of diverse leucocytes in TBL has not been done. We show activated and atypical B cells, myeloid dendritic cells (mDCs), classical, non-classical and intermediate monocytes, T regulatory (T regs) cells, CD4⁺ T cell effector memory RA (TEMRA), CD4⁺ effector and CD8⁺ central memory phenotypes were significantly increased in TBL compared to LTB individuals. In contrast, classical memory and plasma B cells, plasmacytoid DCs (pDCs), CD8⁺ TEMRA, CD4⁺ naïve and central memory cells were significantly decreased in TBL compared to LTB individuals. Some of the leucocyte frequencies (atypical memory B cells, pDCs, myeloid-derived suppressor cells, CD4⁺ effector and CD8⁺ central memory was increased; activated memory and plasma B cell, mDCs, classical, non-classical, intermediate monocytes, T regs, CD4⁺ TEMRA, CD4⁺, CD8⁺ naïve and effector memory cells and CD8⁺ central memory cells were decreased) were significantly modulated after anti-TB treatment among TBL individuals. UMAP analysis show that leucocyte subsets or islands expressing specific markers were significantly different in TBL baseline and post-treatment individuals. Overall, we suggest altered frequencies of diverse leucocytes influences the disease pathology and protective immunity in TBL individuals.

Type 2 diabetes mellitus metabolic control correlates with the phenotype of human monocytes and monocyte-derived macrophages

AIMS

Monocytes and macrophages express cell-surface markers indicative of their inflammatory and activation status. In this study, we investigated whether these markers are affected or correlated in non-obese T2D subjects, or glycemic/metabolic control variables.

METHODS

Clinical data was recorded, and peripheral blood drawn from T2D patients (n = 28) and control subjects (n = 27). Isolated monocytes were evaluated by flow cytometry for the expression of CD14, CD16, and the phenotypic markers for the different states of activation spectrum, such as pro-inflammatory (M1) (HLA-DR, CD86), anti-inflammatory/pro-resolving (M2) (CD163, CD206, MERTK, PD-L1) and metabolically-activated (MMe) (CD36, ABCA-1). From a subset of individuals, monocytes-derived macrophages (MDM) were obtained and evaluated for phenotypic markers. A correlation analysis was performed between the clinical variables and the marker expression.

RESULTS

The frequency of CD14⁺⁺CD16^- monocytes was lower in T2D patients and it correlates negatively with poor control in glycemic and metabolic variables. T2D monocytes expressed lower levels of HLA-DR, CD86, PD-L1, and CD163, which correlated negatively with poor metabolic control. In MDM from T2D patients, HLA-DR, CD86 and CD163 expression was lower and it inversely correlated with deficient glycemic or metabolic control parameters.

CONCLUSION

The glycemic/metabolic control associated with T2D influences monocyte and MDM phenotypes toward an immune-suppressive phenotype.

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.

Influence of diabetes mellitus on immunity to human tuberculosis

Type 2 diabetes mellitus(DM) is a major risk factor for the development of active pulmonary tuberculosis (TB), with development of DM pandemic in countries where TB is also endemic. Understanding the impact of DM on TB and the determinants of co-morbidity is essential in responding to this growing public health problem with improved therapeutic approaches. Despite the clinical and public health significance posed by the dual burden of TB and DM, little is known about the immunological and biochemical mechanisms of susceptibility. One possible mechanism is that an impaired immune response in patients with DM facilitates either primary infection with Mycobacterium tuberculosis or reactivation of latent TB. Diabetes is associated with immune dysfunction and alterations in the components of the immune system, including altered levels of specific cytokines and chemokines. Some effects of DM on adaptive immunity that are potentially relevant to TB defence have been identified in humans. In this review, we summarize current findings regarding the alterations in the innate and adaptive immune responses and immunological mechanisms of susceptibility of patients with DM to M. tuberculosis infection and disease.

Modulation of dendritic cell and monocyte subsets in tuberculosis-diabetes co-morbidity upon standard tuberculosis treatment

Type 2 diabetes mellitus (DM) is a major risk factor for the development of active pulmonary tuberculosis (PTB), with development of DM pandemic in countries where tuberculosis (TB) is also endemic. However, the effect of anti-TB treatment on the changes in dentritic cell (DC) and monocyte subset phenotype in TB-DM co-morbidity is not well understood. In this study, we characterized the frequency of DC and monocyte subsets in individuals with PTB with (PTB-DM) or without coincident diabetes mellitus (PTB-NDM) before, during and after completion of anti-TB treatment. PTB-DM is characterized by diminished frequencies of plasmacytoid and myeloid DCs and classical and intermediate monocytes at baseline and 2 months of anti-TB treatment but not following 6 months of treatment completion in comparison to PTB-NDM. DC and monocyte subsets exhibit significant but borderline correlation with fasting blood glucose and glycated hemoglobin levels. Finally, while minor changes in the DC and monocyte compartment were observed at 2 months of treatment, significantly increased frequencies of plasmacytoid and myeloid DCs and classical and intermediate monocytes were observed at the successful completion of anti-TB treatment. Our data show that coincident diabetes alters the frequencies of innate subset distribution of DC and monocytes in TB-DM co-morbidity and suggests that most of these changes are reversible following anti-TB therapy.

Effect of standard tuberculosis treatment on naive, memory and regulatory T-cell homeostasis in tuberculosis-diabetes co-morbidity

Perturbations in CD4(+) and CD8(+) T-cell phenotype and function are hallmarks of tuberculosis-diabetes co-morbidity. However, their contribution to the pathogenesis of this co-morbidity and the effect of anti-tuberculosis treatment on the phenotype of the T-cell subsets is poorly understood. In this study, we examined the frequency of different T-cell subsets in individuals with pulmonary tuberculosis (PTB) with diabetes mellitus (DM) or without coincident diabetes mellitus (NDM) before, during and after completion of anti-tuberculosis chemotherapy. PTB-DM is characterized by heightened frequencies of central memory CD4(+) and CD8(+) T cells and diminished frequencies of naive, effector memory and/or effector CD4(+) and CD8(+) T cells at baseline and after 2 months of treatment but not following treatment completion in comparison with PTB-NDM. Central memory CD4(+) and CD8(+) T-cell frequencies exhibited a positive correlation with fasting blood glucose and glycated haemoglobin A1c levels, whereas the frequencies of naive and effector memory or effector CD4(+) and CD8(+) T cells exhibited a negative correlation. However, the frequencies of CD4(+) and CD8(+) T-cell subsets in individuals with PTB exhibited no significant relationship with bacterial burdens. Finally, although minor alterations in the T-cell subset compartment were observed at 2 months of treatment, significantly decreased frequencies of central memory and significantly enhanced frequencies of naive CD4(+) and CD8(+) T cells were observed at the completion of treatment. Our data reveal a profound effect of coexistent diabetes on the altered frequencies of central memory, effector memory and naive T cells and its normalization following therapy.

Impaired Cytokine but Enhanced Cytotoxic Marker Expression in Mycobacterium tuberculosis-Induced CD8+ T Cells in Individuals With Type 2 Diabetes and Latent Mycobacterium tuberculosis Infection

Type 2 diabetes mellitus (DM) is a risk factor for tuberculosis among individuals with latent Mycobacterium tuberculosis infection. To explore the influence of DM on CD8(+) T-cell responses during latent M. tuberculosis infection, we estimated the cytokine and cytotoxic marker expression pattern in individuals with latent M. tuberculosis infection with DM and those with latent M. tuberculosis infection without DM. Among individuals with latent M. tuberculosis infection, those with DM had diminished frequencies of CD8(+) T-helper type 1 (Th1), Th2, and Th17 cells following stimulation by M. tuberculosis antigen and enhanced frequencies of CD8(+) T cells expressing cytotoxic markers, compared with those without DM. Thus, our results suggest that coincident DM modulates CD8(+) T-cell function during latent M. tuberculosis infection.