The role of interferon-gamma in the increased tuberculosis risk in type 2 diabetes mellitus

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.

Association between diabetes mellitus and cause of death in patients with tuberculosis: A Korean nationwide cohort study

Despite its significant impact on mortality, tuberculosis (TB)-diabetes mellitus (DM) co-prevalence has not been well-elucidated for the cause of death. We investigated the impact of DM on TB-related and non-TB-related deaths in patients with TB. This retrospective nationwide cohort study included patients diagnosed with TB between 2011 and 2017 in South Korea. We performed Fine and Gray regression model analyses to assess the mortality risk of DM classified by cause of death. Of 239,848 patients, 62,435 (26.0%) had DM, and 20,203 died during anti-TB treatment. Of all deaths, 47.9% (9,668) were caused by TB, and the remaining 52.1% (10,535) was attributed to various non-TB-related causes. The mortality rate was higher in the DM than in the non-DM groups in both men and women. DM was associated with a higher risk of TB-related (adjusted hazard ratio [aHR] 1.07, 95% confidence interval [CI] 1.01-1.13) and non-TB-related (aHR 1.21, 95% CI 1.15-1.27) deaths in men; however, only a higher risk of non-TB-related deaths (aHR 1.29, 95% CI 1.20-1.38) in women. Our findings indicate that DM is independently associated with a greater risk of death during anti-TB treatment among patients with TB for both TB-related and non-TB-related deaths.

Importance of adjuvant selection in tuberculosis vaccine development: Exploring basic mechanisms and clinical implications

The global emergency of unexpected pathogens, exemplified by SARS-CoV-2, has emphasized the importance of vaccines in thwarting infection and curtailing the progression of severe disease. The scourge of tuberculosis (TB), emanating from the Mycobacterium tuberculosis (Mtb) complex, has inflicted a more profound toll in terms of mortality and morbidity than any other infectious agents prior to the SARS-CoV-2 pandemic. Despite the existence of Bacillus Calmette-Guérin (BCG), the only licensed vaccine developed a century ago, its efficacy against TB remains unsatisfactory, particularly in preventing pulmonary Mtb infections in adolescents and adults. However, collaborations between academic and industrial entities have led to a renewed impetus in the development of TB vaccines, with numerous candidates, particularly subunit vaccines with specialized adjuvants, exhibiting promising outcomes in recent clinical studies. Adjuvants are crucial in modulating optimal immunological responses, by endowing immune cells with sufficient antigen and immune signals. As exemplified by the COVID-19 vaccine landscape, the interplay between vaccine efficacy and adverse effects is of paramount importance, particularly for the elderly and individuals with underlying ailments such as diabetes and concurrent infections. In this regard, adjuvants hold the key to optimizing vaccine efficacy and safety. This review accentuates the pivotal roles of adjuvants and their underlying mechanisms in the development of TB vaccines. Furthermore, we expound on the prospects for the development of more efficacious adjuvants and their synergistic combinations for individuals in diverse states, such as aging, HIV co-infection, and diabetes, by examining the immunological alterations that arise with aging and comparing them with those observed in younger cohorts.

Factors Influencing the Indeterminate Results in a T-SPOT.TB test: A Matched Case-control Study

Objective A T-SPOT.TB can yield indeterminate results under two test observation conditions: a high response to the nil in negative control wells (high nil-control) or a low response to the mitogen in positive control wells (low mitogen-control). The most strongly influential factors for these indeterminate results, however, have yet to be identified. Methods From June 1, 2015, to June 30, 2021, we conducted a 1:1 matched case-control, retrospective study. Patients Patients who underwent a T-SPOT.TB test at Chiba University Hospital. Results The study included 5,956 participants. Indeterminate results were found in 63 participants (1.1%), including high nil-control in 37 and low mitogen-control in 26. Human T-cell leukemia virus type 1 (HTLV-1) positivity was the only influencing factor associated with high nil-control (adjusted odds ratio=98.5, 95% confidence interval: 6.59-1,480). Conclusion Regarding the indeterminate results, all HTLV-1 positive participants had a high nil response and no low mitogen response. It was suspected that abnormally produced interferon γ caused a nonspecific reaction to the negative control well, resulting in a high nil response. Low mitogen-control, conversely, did not appear to have any statistically significant influential factors.

The cause-effect relation of tuberculosis on incidence of diabetes mellitus

Tuberculosis (TB) is one of the oldest human diseases and is one of the major causes of mortality and morbidity across the Globe. Mycobacterium tuberculosis (Mtb), the causal agent of TB is one of the most successful pathogens known to mankind. Malnutrition, smoking, co-infection with other pathogens like human immunodeficiency virus (HIV), or conditions like diabetes further aggravate the tuberculosis pathogenesis. The association between type 2 diabetes mellitus (DM) and tuberculosis is well known and the immune-metabolic changes during diabetes are known to cause increased susceptibility to tuberculosis. Many epidemiological studies suggest the occurrence of hyperglycemia during active TB leading to impaired glucose tolerance and insulin resistance. However, the mechanisms underlying these effects is not well understood. In this review, we have described possible causal factors like inflammation, host metabolic changes triggered by tuberculosis that could contribute to the development of insulin resistance and type 2 diabetes. We have also discussed therapeutic management of type 2 diabetes during TB, which may help in designing future strategies to cope with TB-DM cases.

Interleukin-4 expression is increased in patients with tuberculosis: A systematic review and meta-analysis

BACKGROUND

Interleukin-4 (IL-4) is an important cytokine in the Th2 differentiation of CD4+ T cells, which modulates immune responses and participates in host defense against Mycobacterium tuberculosis. The present study aimed to evaluate the significance of IL-4 concentration in patients with tuberculosis. Data from this study will be helpful in understanding the immunological mechanisms of tuberculosis and in clinical practice.

METHOD

A data search was conducted from January 1995 to October 2022 in electronic bibliographic databases such as China National Knowledge Infrastructure, Wan Fang, Embase, Web of Science, and PubMed. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. Heterogeneity between the studies was assessed using I2 statistics. Publication bias was determined by funnel plot, and Egger's test was used to confirm the presence of publication bias. All qualified studies and statistical analyses were performed using Stata 11.0.

RESULTS

Fifty-one eligible studies comprising 4317 subjects were included in the meta-analysis. The results depicted a considerably increased level of serum IL-4 in patients with tuberculosis than in the controls (standard mean difference [SMD] = 0.630, [95% confidence interval (CI), 0.162-1.092]). However, there was no significant difference in plasma IL-4 levels between patients with TB and controls (SMD = 0.290, [95% CI, -0.430 to 1.010]). In addition, the infection status, TB focus location, drug resistance, race, research design type, and detection method divided the subjects into different subgroups for the meta-analysis. The results of the comparison of healthy controls and TB subjects showed that in the Asian population, the serum IL-4 level in patients with TB was higher than that in controls (SMD = 0.887, [95% CI, 0.202 to -1.573]) and patients with active TB as well as people with pulmonary TB showed increased serum IL-4 levels compared to controls (SMD = 0.689, [95% CI, 0.152-1.226]). In the case of the control group with latent TB, the active TB group had higher serum IL-4 levels than the control group (SMD = 0.920, [95% CI, 0.387-1.452]).

CONCLUSION

The present meta-analysis showed that serum IL-4 varied in healthy individuals and patients with TB. Patients with active TB may also exhibit higher IL-4 concentrations.

Advancing personalized medicine for tuberculosis through the application of immune profiling

While early and precise diagnosis is the key to eliminating tuberculosis (TB), conventional methods using culture conversion or sputum smear microscopy have failed to meet demand. This is especially true in high-epidemic developing countries and during pandemic-associated social restrictions. Suboptimal biomarkers have restricted the improvement of TB management and eradication strategies. Therefore, the research and development of new affordable and accessible methods are required. Following the emergence of many high-throughput quantification TB studies, immunomics has the advantages of directly targeting responsive immune molecules and significantly simplifying workloads. In particular, immune profiling has been demonstrated to be a versatile tool that potentially unlocks many options for application in TB management. Herein, we review the current approaches for TB control with regard to the potentials and limitations of immunomics. Multiple directions are also proposed to hopefully unleash immunomics' potential in TB research, not least in revealing representative immune biomarkers to correctly diagnose TB. The immune profiles of patients can be valuable covariates for model-informed precision dosing-based treatment monitoring, prediction of outcome, and the optimal dose prediction of anti-TB drugs.

Demographic and Clinical Determinants of Tuberculosis and TB Recurrence: A Double-Edged Retrospective Study from Pakistan

Objective. TB recurrence is the second episode of TB after initial treatment bringing about an additional 7% load in TB burden intensified by 17.7% of multidrug-resistant recurrent cases. It is necessary to curb recurrence so that attempts to deal with active disease can be made more effective. This study aimed to characterize sociodemographic and clinical factors associated with recurrent TB in a high-burden setting. Methodology. A retrospective case-control study was carried out at two hospitals in Rawalpindi, Pakistan. TB patients and controls were included in the study. Sociodemographic and clinical data were collected by questionnaire from all subjects. Multivariate regression analysis was performed to determine factors associated with TB and TB recurrence respectively. Results. In our study cohort, factors significantly associated with TB were low BMI (OR: 0.961 (CI 0.954–0.968), $p<0.001$ ), female gender (OR: 2.065 (CI 1.922–2.219), $p<0.001$ ), being single/unmarried (OR: 1.214 (CI 1.109–1.328), $p=0.003$ ), middle-income status (OR: 1.935 (CI 1.616–2.323), $p<0.001$ ), smoking (OR: 1.567 (CI 1.435–1.710), $p<0.001$ ), and diabetes mellitus (OR: 1.142 (CI 1.017–1.278), $p=0.023$ ). TB recurrence constituted 11.2% of patients presenting to the hospital. Compared with the first episode of TB, cases with recurrence were more likely to be older (OR: 1.011 (CI 1.004–1.017), $p<0.001$ ), have disease awareness (OR: 1.906 (CI 1.486–2.437), $p<0.001$ ), smear positive (OR: 2.384 (CI 1.650–3.536), $p<0.001$ ), and be drug-resistant (OR: 5.615 (CI 4.265–7.386), $p<0.001$ ). Conclusion. In the present study cohort, low BMI, female gender, being single, middle-income status, being unemployed, smoking, and being diabetic came out to be the sociodemographic and clinical risk factors for TB. Further exploring the TB cases increasing age, drug resistance and smear positivity stood out to be the major sociodemographic and clinical factors of TB recurrence despite high disease awareness.

Prevalence of Pulmonary Tuberculosis in Diabetic Patients: Epidemiology, Immunological Basis, and Its Amalgamated Management

Tuberculosis (TB) is one of the most widespread and infectious diseases in the world, which is brought on by Mycobacterium tuberculosis (MTB). Most infection lacks traditional signs. Latent TB is the name given to this ailment. Of these latent infections, 10% become active and cause illness. Fever, night sweats, a prolonged cough with blood-containing mucus, and weight loss are common signs of active TB infection. Diabetes, on the other hand, is a group of metabolic illnesses characterized by elevated serum glucose levels. It is a chronic metabolic condition brought on by a deficiency in insulin secretion or resistance. It is of two types, that is, type 1 and type 2. Among all the cases of diabetes, the occurrence of type 2 is more common and less fatal than type 1. The prevalence of diabetes is currently increasing in low- and middle-income nations. As both diabetes and TB come under the most widespread chronic condition; therefore, their combined effect is evaluated. In recent years, the higher occurrence of TB in patients with hyperglycemia has come to light. People with elevated blood glucose levels exhibit several risk factors that make them more vulnerable to contracting TB. This review provides information on epidemiological data about the prevalence of TB in patients with hyperglycemia. In addition, this paper discusses the immunological underpinnings of TB development in patients with diabetes mellitus and how glycemic management reduces the risk of TB infection. It illustrates how the clinical signs and radiographic evidence of TB differ between people with diabetes and healthy people and mentions diabetes and TB combined management.

Pulmonary tuberculosis and diabetes mellitus: Clinical profile and outcomes

Background

India is endemic for Tuberculosis (TB), contributing to the world's highest number of active cases. Diabetes (DM), with its increasing burden in India, could contribute to adverse outcomes among patients with TB.

Methods

Consecutive patients with sputum smear positive pulmonary tuberculosis were included in the study. We defined cases as those patients with diabetes at recruitment. Controls were non diabetics (NDM). Sputum samples for AFB smears, AFB culture and Xpert PCR along with blood samples for glycosylated Haemoglobin and glucose levels were collected at recruitment and at 6 months from patients with sputum positive pulmonary TB. Blood glucose levels and sputum smears were repeated at 2 months and monthly till they tested negative. The primary outcome studied was mortality at 6 month follow-up. The secondary outcomes included the time to conversion of sputum smears and cure rates between cases and controls.

Results

We recruited 124 patients of which 68 were cases. Mortality after therapy was 15% in cases and 7% in controls, however, the difference was not statistically significant. Equal proportions in each group (Diabetics: 9% vs. NDM 9%) had persistent smear positivity at 2 months. There was no association between delayed sputum conversion and uncontrolled diabetes. Only about 57% of cases and 50% of controls were documented to have completed treatment or been cured. A significant reduction in HbA1c after 6 months of Antituberculous therapy was noted among the cases. [Mean difference - 1.76, P-value - 0.001, 95% CI of difference - (1.01 - 2.52)].

Conclusions

Diabetes did not have adverse outcomes in the form of increased mortality or delayed sputum conversion rates. The high proportion of loss to follow-up seems to be a trend of concern, which should be addressed emergently.

Tuberculosis in an Aging World

Tuberculosis (TB) is one of the leading causes of death due to its being an infectious disease, caused by the airborne pathogen Mycobacterium tuberculosis (M.tb). Approximately one-fourth of the world’s population is infected with latent M.tb, and TB is considered a global threat killing over 4000 people every day. The risk of TB susceptibility and mortality is significantly increased in individuals aged 65 and older, confirming that the elderly represent one of the largest reservoirs for M.tb infection. The elderly population faces many challenges that increase their risk of developing respiratory diseases, including TB. The challenges the elderly face in this regard include the following: decreased lung function, immuno-senescence, inflammaging, adverse drug effects, low tolerance to anti-TB drugs, lack of suitable diagnoses/interventions, and age-associated comorbidities. In order to find new therapeutic strategies to maintain lung homeostasis and resistance to respiratory infections as we age, it is necessary to understand the molecular and cellular mechanisms behind natural lung aging. This review focuses primarily on why the elderly are more susceptible to TB disease and death, with a focus on pulmonary function and comorbidities.

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.

High Glucose Concentrations Impair the Processing and Presentation of Mycobacterium tuberculosis Antigens In Vitro

Type 2 diabetes is an established risk factor for tuberculosis, but the underlying mechanisms are largely unknown. We established an in vitro model to analyze the effect of high glucose concentrations in antigen processing and presentation in antigen-presenting cells. Human monocyte-derived macrophages (MDMs) were exposed to high (11 mM and 30 mM) and low (5.5 mM) glucose concentrations and infected with Mycobacterium tuberculosis (Mtb). Flow cytometry was used to analyze the effect of high glucose concentrations in histocompatibility complex (MHC) class II molecules (HLA-DR) and co-stimulatory molecules (CD80 and CD86), indispensable for an adequate antigenic presentation and CD4+ T cell activation. HLA-DR and CD86 were significantly decreased by high glucose concentrations compared with low glucose concentrations. Confocal microscopy was used to detect Rab 5 and Lamp-1, proteins involved in the kinetics of antigen processing as early markers, and Rab 7 and cathepsin D as late markers. We observed a delay in the dynamics of the acquisition of Rab 7 and cathepsin D in high glucose concentrations. Moreover, the kinetics of the formation M. tuberculosis peptide-MHC II complexes in MDMs was decreased under high glucose concentrations, reducing their capacity for T cell activation. These findings suggest that high glucose concentrations directly affect antigenic processing, and therefore antigenic presentation.

The impact of diabetes on cutaneous leishmaniasis: a case-control field assessment

This study aimed to assess the associated-risk determinants for cutaneous leishmaniasis (CL) in patients with diabetes mellitus (DM) compared to patients without DM. This case-control study was performed between 2017 and 2019 in southeastern Iran. Overall, 206 participants were selected from patients with DM without CL (11.2%), patients with CL without DM (6.2%), and DM patients concomitance with CL (27.6%) as case groups and healthy individuals as a control group 64 (76%). These cases were compared for parasitological, immunological, biochemical, and hematological parameters. The findings demonstrated that parasitological factors regarding the number, duration, and size of the lesion in CL patients showed a significant difference among patients with and without DM (p < 0.05). Data analysis showed that six major risk factors, including female (odds ratio (OR) = 3.47, confidence interval (CI) = 1.84-6.53, p < 0.001), total protein in CL group (OR = 4.9, CI = 2.3-10.44, p < 0.001), alanine aminotransferase (ALT) concentration in CL group (OR = 0.87, CI = 0.81-0.93, p < 0.001) and DM co-infected with CL group (OR = 0.8, CI = 0.72-0.88, p < 0.001) than healthy group, aspartate aminotransferase (AST) concentration in DM group (OR = 0.86, CI = 0.76-0.98, p = 0.02), transforming growth factor beta)TGF-β( level in the CL group (OR = 1.03, CI = 1.003-1.05, p = 0.02), and presence of diabetes disease (OR = 2.07, CI = 1.16-3.7, p < 0.05), were significantly linked with the induction of CL lesion. The findings demonstrated a significant relationship between DM and CL in distinct risk determinants. Also, the study revealed that DM enhanced the severity of active CL.

Understanding the increased risk of infections in diabetes: innate and adaptive immune responses in type 1 diabetes

AIMS

Patients with diabetes have a higher incidence of infections with Candida albicans, Staphylococcus aureus and Mycobacterium tuberculosis, yet factors contributing to this increased risk are largely unknown. We hypothesize that altered innate and adaptive immune responses during diabetes contribute to an increased susceptibility to infections.

MATERIALS AND METHODS

We studied cytokine responses to ex vivo pathogenic stimulations in a cohort with type 1 diabetes (n = 243) and non-diabetic healthy control subjects (n = 56) using isolated peripheral blood mononuclear cells (PBMCs). Clinical phenotypical data including BMI, duration of diabetes, and HbA_1c levels were collected and related to the cytokine production capacity.

RESULTS

Adjusted for age, sex and BMI, the presence of diabetes was associated with significantly lower IL-1β, IL-6, TNF-α, and IL-17 production upon ex vivo stimulation of PBMCs with C. albicans and S. aureus (all, p < 0.05). In response to stimulation with M. tuberculosis only IL-17 (p < 0.001) was lower in patients with diabetes. Patients with the shortest diabetes duration had a significant lower IL-1β, IL-6 and TNF-α production (all, p < 0.01) after M. tuberculosis stimulation. Older patients had a significant lower IFN-γ (p < 0.05) production after stimulation with all three pathogens. HbA_1c levels and BMI had no significant impact on cytokine production.

CONCLUSIONS

PBMCs of patients with type 1 diabetes demonstrate significantly lower cytokine production in response to stimulation with several pathogens, which likely explain, at least in part, the increased susceptibility for these infections.

HLA-DRB1 genes and the expression dynamics of HLA CIITA determine the susceptibility to T2DM

Type 2 diabetes mellitus (T2DM) is a disease with polygenic inheritance. The expression of major histocompatibility complex class II genes are regulated by several trans-activators. We have studied the expression of HLA-DRB1, RFX, CIITA-P1, PIV transactivators, immunophenotyping of cells, SNPs in CIITA-168 (A/G) and IFN-γ + 874 (T/A) in T2DM patients and controls (n = 201 each). We observed increased frequencies of DRB1*03, DRB1*04 and DRB1*07 and decreased frequencies of DRB1*10, DRB1*14, and DRB1*15 alleles among patients. Significant up-regulations of HLA-DRB1 genes were observed in patients (p < 0.0001). Down-regulated expressions were documented in DRB1*03-homo (p < 0.002) and DRB1*04-homo (p < 0.009) patients. No significant differences were observed for CIITA-P1 expression except DRB1*04-pooled (p < 0.0113). The CIITA-PIV was up-regulated in overall (p < 0.0001), DRB1*03-pooled (p < 0.0006), DRB1*03-hetero (p < 0.0006) and DRB1*03-homo (p < 0.001) T2DM patients. However, significant down-regulations were documented for DRB1*04-pooled (p < 0.040), DRB1*04-hetero (p < 0.060), and DRB1*04-homo (p < 0.027) combinations. Further, significant down-regulations of RFX5 were observed in overall (p < 0.0006), DRB1*04-pooled (p < 0.0022), and DRB1*04-hetero (p < 0.0004) combinations. Immunophenotyping studies revealed significant increase of CD45⁺ CD14^-, CD19⁺, CD14^- and CD8 cells and elevated level of expression of IFN-γ (p < 0.0001) in patients. A significant increase of TT (p < 3.35 × 10^-6) and decrease of TA (p < 4.57 × 10^-4) genotypes of IFN-γ + 874 (T/A) and an increase of GG (p < 0.001) and decrease of AG (p < 8.24 × 10^-5) genotypes of CIITA-168 A/G SNPs were observed. The combinatorial analysis revealed susceptible associations for DRB1*03 + AA, *03 + AG, *03 + GG and *04 + GG and protective associations for DRB1*10 + AG, *10 + GG, *15 + AG, and *14 + GG combinations. Thus, the present study corroborated the effect of differential expressions of promoters of risk alleles in the pathogenesis of T2DM.

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.

Impact of Low Interferon-γ and IL-10 Levels on TNF-α and IL-6 Production by PHA-Induced PBMCs in Type 2 Diabetes Mellitus

Purpose

In this study, we analyzed the production of interferon γ (IFN-γ) and interleukin 10 (IL-10) by peripheral blood mononuclear cells (PBMCs) in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the capacity of monocytes to produce tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) following IFN-γ stimulation and the associated role of IL-10 in TNF-α and IL-6 production.

Patients and Methods

In vitro experiments were conducted on PBMCs obtained from 19 patients with T2DM and 17 healthy participants. PBMCs were isolated from venous blood by density gradient centrifugation, followed by 3-day phytohemagglutinin induction. In vitro production of TNF-α, IL-6, IFN-γ, and IL-10 was measured using the multiplex immunoassay. Statistical analysis was performed using IBM SPSS 23 version.

Results

IFN-γ concentration in the T2DM group was significantly lower than that in control group (T2DM 7,700.86 ± 3,037.77 vs control 10,672.69 ± 5,625.50 pg/mL; p = 0.048). However, TNF-α, IL-6, and IL-10 levels showed no significant difference between the two groups. The TNF-α/IFN-γ and IL-6/IFN-γ ratios were significantly higher in T2DM than in the control group (p = 0.026 and p = 0.048, respectively). In T2DM, the high TNF-α/IFN-γ ratio was consistent, with the low baseline IL-10 level (p = 0.022).

Conclusion

In T2DM, T-cell response is impaired with significantly reduced IFN-γ production, and simultaneously, circulatory monocytes show enhanced cellular responsiveness to inflammatory stimuli. The low baseline IL-10 level likely contributes to such an immune response.

Adults with Mycobacterium tuberculosis infection and pre-diabetes have increased levels of QuantiFERON interferon-gamma responses

BACKGROUND

Diabetes is associated with increased prevalence of TB infection in the US. We assessed associations between diabetes and interferon-gamma (IFN-γ) TB antigen response among adults with TB infection using US representative data.

METHODS

National Health and Nutrition Examination (NHANES) participants >19 years from 2011 to 2012 with positive QuantiFERON®-TB Gold-In-Tube (QFT) results were eligible. Diabetes was defined by combination of self-report and glycated hemoglobin (HbA1c). Quantitative IFN-γ TB antigen was classified as high (≥10 IU/mL), intermediate (1.01-9.99 IU/mL), or low (0.35-1.00 IU/mL). Analyses accounted for NHANES weighted design.

RESULTS

Among NHANES participants >19 years, n = 513 had positive QFT (5.9%). Among those with positive QFT, diabetes prevalence was 22.2% and pre-diabetes was 25.9%. Overall, 16.7% of positive QFT participants had high IFN-γ TB antigen levels including 21.7% among those with diabetes, 20.8% among those with pre-diabetes, and 12.6% among euglycemic participants. In adjusted analyses, high IFN-γ TB antigen response was more common among those with pre-diabetes (aOR 1.9, 95%CI 1.0, 3.6) compared to euglycemic participants.

CONCLUSION

Higher antigen responses may reflect immunopathy consistent with an exaggerated inflammatory but ineffectual response to TB or a reflection of more Mtb replication in participants with pre-diabetes or diabetes.

Evidence for a More Disrupted Immune-Endocrine Relation and Cortisol Immunologic Influences in the Context of Tuberculosis and Type 2 Diabetes Comorbidity

Pulmonary tuberculosis (PTB), caused by Mycobacterium tuberculosis (Mtb), is a major health problem worldwide, further aggravated by the convergence of type 2 diabetes mellitus (DM) which constitutes an important risk factor for TB development. The worse scenario of patients with PTB and DM may be partly related to a more unbalanced defensive response. As such, newly diagnosed PTB patients with DM (TB+DM, n = 11) or not (TB, n = 21), as well as DM (n = 18) patients and pair matched controls (Co, n = 22), were investigated for the circulating immuno-endocrine-metabolic profile (ELISA), along with studies in peripheral blood mononuclear cells (PBMC) analyzing transcript expression (RT-qPCR) of mediators involved in glucocorticoid functionality. Given the hyperglycemic/hypercortisolemic scenario of TB+DM patients, PBMC were also exposed to stress-related cortisol concentrations (0.1 and 1 μM) and supraphysiologic glucose doses (10, 20, and 40 mM) and assessed for the specific response against Mtb stimulation (lymphoproliferation, -thymidine incorporation-, and cytokine production -bead-cytometry). All TB patients displayed increased plasma amounts of cortisol, growth hormone -hGH-, and proinflammatory mediators. In turn, TB+DM showed even higher levels of interferon gamma -IFN-γ- and hGH (vs. TB), or IL-6, C reactive protein, cortisol and hGH (vs. DM). Both DM groups had equally augmented values of IL-10. All TB patients showed decreased dehydroepiandrosterone- sulfate concentrations, even more in TB+DM cases. Leptin was also decreased in both TB cases, particularly in the TB group, revealing a lower body mass index, as well. Unlike PBMC from TB cases showing a decreased relationship between the glucocorticoids receptor (GR) isoforms (GRα/GRβ; functional isoform/negative isoform), cells from TB+DM patients had no changes in this regard, along with an increased expression of 11-beta hydroxysteroid dehydrogenase type-1, the enzyme facilitating intracellular cortisone to cortisol conversion. TB+DM patients also showed an increased Mtb antigen-driven lymphoproliferation. Compared to TB, DM and HCo counterparts, PBMC from TB+DM patients had a biased Th1 response to Mtb stimulation (increased IL-2 and IFN-γ production), even when exposed to inhibitory cortisol doses. TB+DM patients show a more unbalanced immuno-endocrine relationship, respect the non-diabetic counterparts, with a relative deficiency of cortisol immunomodulatory influences, despite their more favorable microenvironment for cortisol-mediated immune effects.

Forecasting the impact of diabetes mellitus on tuberculosis disease incidence and mortality in India

Background

In context of the rapidly expanding diabetes mellitus (DM) epidemic in India and slowly declining tuberculosis (TB) incidence, we aimed to estimate the past, current, and future impact of DM on TB epidemiology.

Methods

An age-structured TB-DM dynamical mathematical model was developed and analyzed to assess the DM-on-TB impact. The model was calibrated using a literature review and meta-analyses. The DM-on-TB impact was analyzed using population attributable fraction metrics. Sensitivity analyses were conducted by accommodating less conservative effect sizes for the TB-DM interactions, by factoring the age-dependence of the TB-DM association, and by assuming different TB disease incidence rate trajectories.

Results

In 1990, 11.4% (95% uncertainty interval (UI) = 6.3%-14.4%) of new TB disease incident cases were attributed to DM. This proportion increased to 21.9% (95% UI = 12.1%-26.4%) in 2017, and 33.3% (95% UI = 19.0%-44.1%) in 2050. Similarly, in 1990, 14.5% (95% UI = 9.5%-18.2%) of TB-related deaths were attributed to DM. This proportion increased to 28.9% (95% UI = 18.9%-34.1%) in 2017, and 42.8% (95% UI = 28.7%-53.1%) in 2050. The largest impacts originated from the effects of DM on TB disease progression and infectiousness. Sensitivity analyses suggested that the impact could be even greater.

Conclusions

The burgeoning DM epidemic is predicted to become a leading driver of TB disease incidence and mortality over the coming decades. By 2050, at least one-third of TB incidence and almost half of TB mortality in India will be attributed to DM. This is likely generalizable to other Asian Pacific countries with similar TB-DM burdens. Targeting the impact of the increasing DM burden on TB control is critical to achieving the goal of TB elimination by 2050.

Pancreatic tuberculosis: A systematic review of symptoms, diagnosis and treatment

INTRODUCTION

Although pancreatic tuberculosis (TB) is traditionally considered to be a rare clinical entity, in recent times, an increase in the number of reports of pancreatic TB has been noted. We conducted a systematic review in order to summarise currently available data on pancreatic TB.

METHODS

A comprehensive literature search of Medline, Scopus and ISI Web of Science databases was conducted in order to identify papers reporting cases of pancreatic TB. The eligibility criteria for inclusion in the review required that the studies reported patient(s) affected by pancreatic TB and that individual data on age, sex, clinical presentation and outcome were available.

RESULTS

In total, 116 studies reporting data on 166 patients were included in the analysis. The majority of patients were males (62.1%) diagnosed at a mean age of 41.61 ± 13.95 years. Most cases were diagnosed in Asia (50.0%), followed by North America (22.9%), Europe (20.5%), Africa (4.2%) and South America (2.4%). Human immunodeficiency virus (HIV) infection was diagnosed in 25.3% of those affected. Pancreatic TB most frequently presented itself in the form of a pancreatic mass (79.5%) localised mainly in the head (59.0%) and less frequently in the body (18.2%) and tail (13.4%). Extrapancreatic TB involvement most frequently affected the peripancreatic lymph nodes (47.3%). More than half of patients (55.2%) were subjected to laparotomy, while 21.08% underwent endoscopic ultrasound fine-needle aspiration biopsy. The presence of TB was identified most frequently through histological analysis (59.6%), followed by culture (28.9%), staining (27.7%) and, in a smaller number, by polymerase chain reaction (9.6%) and cytology (6.6%). Almost all patients received anti-tubercular pharmacological therapy (98.2%), while 24.1% underwent surgery. Despite treatment, 8.7% of patients died.

CONCLUSION

Increased awareness of pancreatic TB is needed, not only in endemic areas but especially in relation to HIV infection and other clinical conditions associated with immunoincompetence.

Association of social deprivation and outdoor air pollution with pulmonary tuberculosis in spatiotemporal analysis

The objective of this study was to identify the association between social deprivation, outdoor air pollution, and tuberculosis (TB) incidence rate or mortality rate. The study sample comprised 25 districts in Seoul, Korea. We used two public data derived from the Community Health Survey and Seoul Statistics. The geographic information system analysis and random effects Poisson regression were applied to explore the association of social deprivation and air pollution with TB incidence and mortality. An 1 ppb increase in sulfur dioxide (SO₂) concentration was significantly associated with the risk of TB incidence (risk ratio [RR] = 1.046, 95% confidence interval [CI]: 1.028, 1.065). An 1 unit increase in the deprivation index was significantly related to a6% increase in the mortality of TB (RR = 1.063, 95% CI: 1.031, 1.097). : Our results imply that social deprivation and air pollution may affect the different TB outcomes. Effective policy-making for TB control should reflect the differing outcomes between TB incidence and mortality.

Impacts of metformin on tuberculosis incidence and clinical outcomes in patients with diabetes: a systematic review and meta-analysis

BACKGROUND

Accumulating evidence suggested that the use of metformin had more benefits for both prevention and treatment of tuberculosis (TB) than non-metformin use in patients with diabetes mellitus (DM); however, it remains to be fully elucidated on this topic. Thus, we conducted a systematic review and meta-analysis of published studies to determine the association between metformin use and TB in patients with diabetes.

METHODS

The MEDLINE, EMBASE, Information Sciences Institute (ISI) Web of Science, and Cochrane CENTRAL databases were searched from their inception to 15 April 2019. Studies that evaluated the use of metformin and TB disease were included. The quality of each study was evaluated through the Newcastle-Ottawa Scale (NOS). For pooled data, the relative risk (RR) and 95% confidence intervals (CIs) were calculated; otherwise, a systematic review.

RESULTS

Seventeen observational studies were included, all of which indicated a low risk of bias according to the NOS. The pooled analysis showed that metformin use was associated with a significantly lower active TB incidence and mortality among individuals with DM (RR = 0.51; 95% CI, 0.38-0.69, P ⩽ 0.001) and with TB-DM (RR = 0.34; 95% CI, 0.20-0.57, P ⩽ 0.001), respectively.

CONCLUSIONS

This meta-analysis indicated metformin use is related to benefits in both prevention and treatment outcomes of tuberculosis among patients with diabetes. Prospective clinical trials are needed to confirm these associations.

Immunological Impacts of Diabetes on the Susceptibility of Mycobacterium tuberculosis

The interaction between diabetes and major world infections like TB is a major public health concern because of rapidly rising levels of diabetes. The dual burden of tuberculosis (TB) and diabetes mellitus (DM) has become a major global public health problem. Diabetes mellitus is a major risk factor for the development of active and latent tuberculosis. Immune mechanisms contributing to the increased susceptibility of diabetic patients to TB are due to the defects in bacterial recognition, phagocytic activity, and cellular activation which results in impaired production of chemokines and cytokines. The initiation of adaptive immunity is delayed by impaired antigen-presenting cell (APC) recruitment and function in hyperglycemic host, which results in reduced frequencies of Th1, Th2, and Th17 cells and its secretion of cytokines having a great role in activation of macrophage and inflammatory response of tuberculosis. In addition, impaired immune response and killing of intracellular bacteria potentially increase bacterial load, chronic inflammation, and central necrosis that facilitate bacterial dissemination and miliary tuberculosis. Understanding of the immunological and biochemical basis of TB susceptibility in diabetic patients will tell us the rational development of implementation and therapeutic strategies to alleviate the dual burden of the diseases. Therefore, the aim of this review was focused on the association between diabetes and tuberculosis, focusing on epidemiology, pathogenesis, and immune dysfunction in diabetes mellitus, and its association with susceptibility, severity, and treatment outcome failure to tuberculosis.

Diabetic lung disease: fact or fiction?

Diabetes mellitus is a chronic, progressive, incompletely understood metabolic disorder whose prevalence has been increasing steadily worldwide. Even though little attention has been paid to lung disorders in the context of diabetes, its prevalence has recently been challenged by newer studies of disease development. In this review, we summarize and discuss the role of diabetes mellitus involved in the progression of pulmonary diseases, with the main focus on pulmonary fibrosis, which represents a chronic and progressive disease with high mortality and limited therapeutic options.

The role of epigenetics, bacterial and host factors in progression of Mycobacterium tuberculosis infection

Tuberculosis (TB) infection caused by Mycobacterium tuberculosis (Mtb) is still a persistent global health problem, particularly in developing countries. The World Health Organization (WHO) reported a mortality rate of about 1.8 million worldwide due to TB complications in 2015. The Bacillus Calmette-Guérin (BCG) vaccine was introduced in 1921 and is still widely used to prevent TB development. This vaccine offers up to 80% protection against various forms of TB; however its efficacy against lung infection varies among different geographical settings. Devastatingly, the development of various forms of drug-resistant TB strains has significantly impaired the discovery of effective and safe anti-bacterial agents. Consequently, this necessitated discovery of new drug targets and novel anti-TB therapeutics to counter infection caused by various Mtb strains. Importantly, various factors that contribute to TB development have been identified and include bacterial resuscitation factors, host factors, environmental factors and genetics. Furthermore, Mtb-induced epigenetic changes also play a crucial role in evading the host immune response and leads to bacterial persistence and dissemination. Recently, the application of GeneXpert MTB/RIF^® to rapidly diagnose and identify drug-resistant strains and discovery of different molecular markers that distinguish between latent and active TB infection has motivated and energised TB research. Therefore, this review article will briefly discuss the current TB state, highlight various mechanisms employed by Mtb to evade the host immune response as well as to discuss some modern molecular techniques that may potentially target and inhibit Mtb replication.

The effect of metformin on culture conversion in tuberculosis patients with diabetes mellitus

BACKGROUND/AIMS

Patients with diabetes mellitus (DM) and tuberculosis (TB) have increased morbidity and a high risk of treatment failure or recurrence. It is important to manage both diseases simultaneously. Among anti-diabetic drugs, metformin inhibits intracellular growth of mycobacteria. Therefore, we examined the effects of metformin on TB treatment, especially in patients with DM.

METHODS

This retrospective cohort study included patients with culture-positive pulmonary TB diagnosed between 2011 and 2012. The primary study outcome was sputum culture conversion after 2 months of treatment.

RESULTS

Of 499 patients diagnosed with culture-positive pulmonary TB, 105 (21%) had DM at diagnosis. Among them, 62 (59.5%) were treated with metformin. Baseline characteristics, except for the presence of chronic renal disease, were not significantly different between the metformin and non-metformin groups. Metformin treatment had no significant effect on sputum culture conversion (p = 0.60) and recurrence within 1 year after TB treatment completion (p = 0.39). However, metformin improved the sputum culture conversion rate in patients with cavitary pulmonary TB, who have higher bacterial loads (odds ratio, 10.8; 95% confidence interval, 1.22 to 95.63).

CONCLUSION

Among cavitary pulmonary TB patients with DM, metformin can be an effective adjunctive anti-TB agent to improve sputum culture conversion after 2 months of treatment.

Hyperglycaemia is inversely correlated with live M. bovis BCG-specific CD4+ T cell responses in Tanzanian adults with latent or active tuberculosis

Introduction

The rising prevalence of Diabetes mellitus (DM) in high TB‐endemic countries may adversely affect sustainability of TB control since DM constitutes a risk factor for development of active tuberculosis (TB). The impact of DM on TB specific adaptive immune responses remains poorly addressed, particularly in people living in Sub‐Saharan countries. We performed a functional characterization of TB specific cellular immune response in Tanzanian subjects with active or latent Mycobacterium tuberculosis (Mtb) infection stratified by their diabetic status.

Methods

HIV negative active TB patients (≥18 years) with Xpert MTB/RIF positive pulmonary TB were included before starting TB treatment in Dar es Salaam, Tanzania between April and December 2013. HIV negative healthy controls latently infected with TB but without past TB history were also included. Active and latent TB patients were stratified in two groups according to their diabetic status. Peripheral Blood Mononuclear cells were stimulated with either live M. bovis BCG or Mtb‐specific peptide pools and analyzed by intracellular cytokine staining and polychromatic flow cytometry.

Results

Our results show a lower frequency of IFN‐γ CD4⁺ T cells in patients with active TB and DM compared to patients with active TB only after live M. bovis BCG (p = 0.04) but not after Mtb peptide pools re‐stimulation. Irrespective of TB status, level of glycaemia is selectively inversely correlated with IFN‐γ and TNF‐α CD4⁺ T cell production (p = 0.02 and p = 0.03) after live M. bovis BCG stimulation.

Conclusions

These results support the hypothesis that hyperglycaemia negatively impacts antigen processing and/or presentation of whole mycobacteria delaying secretion of key cytokines involved in TB immunity.

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 diabetes mellitus and active tuberculosis: A systematic review and meta-analysis

The burgeoning epidemic of diabetes mellitus (DM) is one of the major global health challenges. We systematically reviewed the published literature to provide a summary estimate of the association between DM and active tuberculosis (TB). We searched Medline and EMBASE databases for studies reporting adjusted estimates on the TB–DM association published before December 22, 2015, with no restrictions on region and language. In the meta-analysis, adjusted estimates were pooled using a DerSimonian-Laird random-effects model, according to study design. Risk of bias assessment and sensitivity analyses were conducted. 44 eligible studies were included, which consisted of 58,468,404 subjects from 16 countries. Compared with non-DM patients, DM patients had 3.59–fold (95% confidence interval (CI) 2.25–5.73), 1.55–fold (95% CI 1.39–1.72), and 2.09–fold (95% CI 1.71–2.55) increased risk of active TB in four prospective, 16 retrospective, and 17 case-control studies, respectively. Country income level (3.16–fold in low/middle–vs. 1.73–fold in high–income countries), background TB incidence (2.05–fold in countries with >50 vs. 1.89–fold in countries with ≤50 TB cases per 100,000 person-year), and geographical region (2.44–fold in Asia vs. 1.71–fold in Europe and 1.73–fold in USA/Canada) affected appreciably the estimated association, but potential risk of bias, type of population (general versus clinical), and potential for duplicate data, did not. Microbiological ascertainment for TB (3.03–fold) and/or blood testing for DM (3.10–fold), as well as uncontrolled DM (3.30–fold), resulted in stronger estimated association. DM is associated with a two- to four-fold increased risk of active TB. The association was stronger when ascertainment was based on biological testing rather than medical records or self-report. The burgeoning DM epidemic could impact upon the achievements of the WHO “End TB Strategy” for reducing TB incidence.

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene single nucleotide polymorphisms and its interaction with T2DM on pulmonary tuberculosis in Chinese Uygur population

Aims

To investigate the association of several single nucleotide polymorphisms (SNPs) within Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene and additional gene- gene and gene- type 2 diabetes mellitus (T2DM) interaction with pulmonary tuberculosis (PTB) risk in Chinese Uygur population.

Methods

A total of 722 participants (186 males, 536 females) were selected, including 360 PTB patients and 362 control participants. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best interaction combination among SNPs and T2DM. Logistic regression was performed to investigate association between 3 SNPs within PTPN22 gene, additional gene- gene and gene- T2DM interaction on PTB risk.

Results

Logistic regression analysis showed that PTB risk was significantly lower in carriers with rs2476601- CT genotype than those with CC genotype (CT versus CC), adjusted OR (95%CI) =0.42 (0.17-0.83), and higher in carriers with the rs33996649- GA genotype than those with GG genotype (GA versus GG), adjusted OR (95%CI) = 5.66 (2.24-9.47). We found a significant two-locus model (p=0.0010) involving rs33996649 and T2DM. Overall, the cross-validation consistency of this two- locus model was 10/ 10, and the testing accuracy was 60.11%. We also conducted stratified analysis for rs33996649 and T2DM using logistic regression. We found that T2DM patients with rs33996649 - GA genotype have the highest PTB risk, compared to non- T2DM patients with rs33996649- GG genotype, OR (95%CI) = 4.52 (2.71 -6.43), after covariates adjustment.

Conclusions

We found that the T allele of rs2476601 and the A allele of rs33996649within PTPN22 gene, interaction between rs2476601 and T2DM were all associated with increased PTB risk.

Impact of diabetes mellitus on indeterminate results of the QuantiFERON TB Gold In-Tube test: A propensity score matching analysis

BACKGROUND

The sensitivity of interferon-gamma release assays (IGRAs) in the detection of Mycobacterium tuberculosis infection could be affected by conditions of immune dysregulation. For this reason, diabetes mellitus (DM) may increase the frequency of indeterminate results of IGRAs. However, there have been inconsistent reports of role of DM on indeterminate IGRA results.

METHODS

We retrospectively reviewed all patients who underwent QuantiFERON-TB Gold In-Tube testing (QFT-GIT) at Chonnam National University Hospital. We collected the clinical and laboratory data of these patients.

RESULTS

Of all 3,391 subjects, 1,265 (37.3%) had a positive QFT-GIT result, 266 (7.8%) had an indeterminate result, and 1,860 (54.9%) had a negative result. The mean age was 54.8 ± 18.1 years and 55.0% of the patients were male. There were 512 (15.1%) patients with DM. Multivariable analysis revealed that systemic corticosteroid use, tuberculosis, lymphocytopenia, low serum albumin, and high serum C-reactive protein (CRP) levels were significantly associated with indeterminate QFT-GIT results. However, DM was not associated with indeterminate QFT-GIT results (adjusted odds ratio, 0.98; 95% confidence interval, 0.69-1.41; P = 0.939). After propensity score matching, DM was not associated with indeterminate results of QFT-GIT.

CONCLUSION

In this large cohort study, DM does not affect the incidence of indeterminate results of QFT-GIT.

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.

IL-6 and IL-18 cytokine gene variants of pulmonary tuberculosis patients with co-morbid diabetes mellitus and their household contacts in Hyderabad

PURPOSE

Association of cytokine genes reflects their susceptibility towards infection and disease in household contacts (HHC) of pulmonary tuberculosis (PTB) patients. Hyperglycemia, a common factor in diabetics might influence their risk towards mycobacterium tuberculosis infection and disease development. This study determines the association of IL-6 and IL-18 cytokine gene variants of TB patients with diabetes mellitus (TBDM) and their HHC in Hyderabad.

METHODS

Single nucleotide polymorphisms of IL-6 (-174 G>C and -572 G>C) and IL-18 (-137 G>C and -607 C>A) cytokine genes were genotyped by Amplification Refractory Mutation System and Restriction Fragment Length polymerase chain reaction in total of 705 subjects comprising of TBDM, their HHC, PTB, DM and Healthy controls (HC).

RESULTS

At IL-6 -174G>C variant, GG genotype, G allele in TBDM and TBDM HHC, at -572G>C variant, C allele in TBDM and GG haplotype in TBDM HHC were showing positive association, however DM have not shown any association at IL-6 polymorphic sites. With respect to the IL-18 gene polymorphisms, at -137 G>C variant, GG genotype was positively associated in PTB while at -607 C>A variant positive association was shown with AC genotype in TBDM, their HHC and DM; GACC diplotype in TBDM and GCGC in PTB.

CONCLUSION

Our findings suggest that susceptible combination of IL-6 and IL-18 cytokine genes associated with disease in the HHCs highlight their risk of inclination towards the disease.

Incident rate and risk factors for tuberculosis among patients with type 2 diabetes: retrospective cohort study in Shanghai, China

OBJECTIVE

To examine the incident rate of tuberculosis (TB) and its associates among adults with type 2 diabetes in Shanghai, China.

METHODS

We conducted a retrospective cohort study among 170 399 patients with type 2 diabetes aged ≥18 years who were registered in Shanghai community-based diabetes management system between 2004 and 2009. Their TB status was tracked until 31 December 2014. Cox regression was performed to identify the risk factors for TB.

RESULTS

We documented 785 new TB cases during 654 977 person-years of follow-up. The incident rate of TB was 224.20 (206.69, 243.16) per 100 000 person-years among men and 51.34 (44.75, 58.92) per 100 000 person-years among women. A 1-unit increase of BMI was associated with a risk reduction in 16% (P < 0.01) for men and a 14% (P < 0.01) reduction for women. TB cases were more likely to be insulin-dependent [men: hazard ratio = 2.13 (1.29, 3.53); women: 3.28 (1.28, 8.39)] and had a poor glucose level initially [men: 1.21 (1.15, 1.27); women: 1.27 (1.18, 1.37)]. The risk factor for TB specific to men was a young age at diagnosis of diabetes, and the protective factor specific to women was actively engaging in physical activity.

CONCLUSIONS

TB incident rate among patients with type 2 diabetes was substantially higher among men than among women. The risk of TB was reversely associated with initial BMI. The severity of poor glucose control among patients with diabetes was also linearly associated with the risk of TB.

Immunological response to Mycobacterium tuberculosis infection in blood from type 2 diabetes patients

The convergence of tuberculosis and diabetes represents a co-epidemic that threatens progress against tuberculosis. We have investigated type 2 diabetes as a risk factor for tuberculosis susceptibility, and have used as experimental model whole blood infected in vitro with Mycobacterium tuberculosis. Blood samples from diabetic patients were found to have a higher absolute neutrophil count that non-diabetic controls, but their immune functionality seemed impaired because they displayed a lower capacity to phagocytose M. tuberculosis, a finding that had been previously reported only for monocytes. In contrast, an increased production of TNFα was detected in infected blood from diabetic patients. Despite the altered phagocytic capacity showed by cells from these patients, the antimicrobial activity measured in both whole blood and monocyte derived macrophages was similar to that of controls. This unexpected result prompts further improvements in the whole blood model to analyze the immune response of diabetes patients to tuberculosis.

The global dynamics of diabetes and tuberculosis: the impact of migration and policy implications

The convergence between tuberculosis (TB) and diabetes mellitus (DM) will represent a major public health challenge in the near future. DM increases the risk of developing TB by two to three times and also increases the risk of TB treatment failure, relapse, and death. The global prevalence of DM is predicted to rise significantly in the next two decades, particularly in some of the low- and middle-income countries with the highest TB burden. Migration may add further complexity to the effort to control the impact on TB of the growing DM pandemic. Migration may increase the risk of DM, although the magnitude of this association varies according to country of origin and ethnic group, due to genetic factors and lifestyle differences. Migrants with TB may have an increased prevalence of DM compared to the native population, and the risk of TB among persons with DM may be higher in migrants than in autochthonous populations. Screening for DM among migrants, screening migrants with DM for active and latent TB, and improving access to DM care, could contribute to mitigate the effects of DM on TB.

Concurrence of Tuberculosis and Other Major Diseases

The chronic respiratory disease of tuberculosis (TB) has become one of the most significant infectious diseases because of its high mortality. It also results in serious social and economic problems that challenge global public health. Anti-TB treatment has achieved satisfactory results; however, concurrence with other diseases such as diabetes, silicosis, malnutrition, or immunosuppressive therapy can significantly interfere with the treatment of TB. Though irregular treatment is the overriding cause of treatment failure, drug-resistant TB or severe TB and complications are also significant factors. Respiratory tract infection and respiratory failure are the leading cause of death for TB.

An adverse immune-endocrine profile in patients with tuberculosis and type 2 diabetes

Diabetes is a risk factor for the development of pulmonary tuberculosis (TB) and both diseases present endocrine alterations likely to play a role in certain immuno-endocrine-metabolic associated disorders. Patients with TB, or with TB and type 2 diabetes (TB + T2DM) and healthy controls (HCo) were assessed for plasma levels of cortisol, dehydroepiandrosterone (DHEA), estradiol, testosterone, growth hormone (GH), prolactin, insulin-like growth factor-1 (IGF-1), cytokines (IL-6, IL-10, IFN-γ) and the specific lymphoproliferative capacity of peripheral blood mononuclear cells. All patients had higher levels of cortisol with a reduction in DHEA, thus resulting in an increased cortisol/DHEA ratio (Cort/DHEA). Increased prolactin and particularly GH levels were found in both groups of TB patients. This was not paralleled by increased concentrations of IGF, which remained within the levels of HCo. Estradiol levels were significantly augmented in patients TB, and significantly more in TB + T2DM, whereas testosterone levels were decreased in both groups of patients. IFN- γ and IL-6 concentrations were significantly increased in all TB, even further in TB + T2DM; while IL-10 was equally increased in both groups of TB patients. The in vitro specific proliferative capacity was decreased in both groups of patients as compared to that of HCo. The adverse immune-endocrine profile of TB seems to be slightly more pronounced in patients who also have T2DM.

The effect of diabetes control status on treatment response in pulmonary tuberculosis: a prospective study

BACKGROUND

Uncontrolled diabetes, unlike controlled diabetes, is associated with an impaired immune response. However, little is known about the impact of the status of diabetes control on clinical features and treatment outcomes in patients with pulmonary TB (PTB). We conducted this study to evaluate whether the status of diabetes control influences clinical manifestations and treatment responses in PTB.

METHODS

A multicentre prospective study was performed between September 2012 and September 2014. The patients were categorised into three groups according to the glycated haemoglobin (HbA1C) level: PTB without diabetes mellitus (non-DM), PTB with controlled diabetes (controlled-DM) and PTB with uncontrolled diabetes (uncontrolled-DM). The primary outcome was the sputum culture conversion rate after 2 months of intensive treatment.

RESULTS

Among 661 patients with PTB, 157 (23.8%) had diabetes and 108 (68.8%) had uncontrolled diabetes (HbA1C≥7.0%). The uncontrolled-DM group exhibited more symptoms, positive sputum smears (p<0.001) and presence of cavities (p<0.001) than the non-DM group. Regarding treatment responses, patients with uncontrolled-DM were more likely to have a positive culture after 2 months (p=0.009) and either treatment failure (p=0.015) or death (p=0.027) compared with the non-DM group. In contrast, those with controlled-DM showed similar treatment responses to the non-DM group. In multivariable analysis, uncontrolled diabetes was an independent risk factor for a positive sputum culture after 2 months of treatment (adjusted OR, 2.11; p=0.042) and either treatment failure or death (adjusted OR, 4.11; p=0.022).

CONCLUSIONS

Uncontrolled diabetes is an independent risk factor for poor treatment response in PTB.

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

The spread of human immunodeficiency virus (HIV) infection within Africa led to marked increases in numbers of cases of tuberculosis (TB), and although the epidemic peaked in 2006, there were still 1.8 million new cases in 2013, with 29.2 million prevalent cases. Half of all TB cases in Africa are in those with HIV co-infection. A brief review of the well-documented main immunological mechanisms of HIV-associated increased susceptibility to TB is presented. However, a new threat is facing TB control, which presents itself in the form of a rapid increase in the number of people living with type II diabetes mellitus (T2DM), particularly in areas that are already hardest hit by the TB epidemic. T2DM increases susceptibility to TB threefold, and the TB burden attributable to T2DM is 15%. This review addresses the much smaller body of research information available on T2DM-TB, compared to HIV-TB comorbidity. We discuss the altered clinical presentation of TB in the context of T2DM comorbidity, changes in innate and adaptive immune responses, including lymphocyte subsets and T-cell phenotypes, the effect of treatment of the different comorbidities, changes in biomarker expression and genetic predisposition to the respective morbidities, and other factors affecting the comorbidity. Although significant gains have been made in improving our understanding of the underlying mechanisms of T2DM-associated increased susceptibility, knowledge gaps still exist that require urgent attention.

Clinical Pharmacokinetics of Rifampin in Patients with Tuberculosis and Type 2 Diabetes Mellitus: Association with Biochemical and Immunological Parameters

Tuberculosis (TB) remains a major public health issue due to the increasing incidence of type 2 diabetes mellitus (T2DM), which exacerbates the clinical course of TB and increases the risk of poor long-term outcomes. The aim of this study was to characterize the pharmacokinetics of rifampin (RIF) and its relationship with biochemical and immunological parameters in patients with TB and T2DM. The biochemical and immunological parameters were assessed on the same day that the pharmacokinetic evaluation of RIF was performed. Factors related to the metabolic syndrome that is characteristic of T2DM patients were not detected in the TB-T2DM group (where predominant malnutrition was present) or in the TB group. Percentages of CD8(+) T lymphocytes and NK cells were diminished in the TB and TB-T2DM patients, who had high tumor necrosis factor alpha (TNF-α) and low interleukin-17 (IL-17) levels compared to healthy volunteers. Delayed RIF absorption was observed in the TB and TB-T2DM patients; absorption was poor and slower in the latter group due to poor glycemic control. RIF clearance was also slower in the diabetic patients, thereby prolonging the mean residence time of RIF. There was a significant association between glycemic control, increased TNF-α serum concentrations, and RIF pharmacokinetics in the TB-T2DM patients. These altered metabolic and immune conditions may be factors to be considered in anti-TB therapy management when TB and T2DM are concurrently present.

Type 2 diabetes mellitus is associated with altered CD8(+) T and natural killer cell function in pulmonary tuberculosis

Type 2 diabetes mellitus (DM) is associated with expanded frequencies of mycobacterial antigen-specific CD4(+) T helper type 1 (Th1) and Th17 cells in individuals with active pulmonary tuberculosis (TB). No data are available on the role of CD8(+) T and natural killer (NK) cells in TB with coincident DM. To identify the role of CD8(+) T and NK cells in pulmonary TB with diabetes, we examined mycobacteria-specific immune responses in the whole blood of individuals with TB and DM (TB-DM) and compared them with those without DM (TB-NDM). We found that TB-DM is characterized by elevated frequencies of mycobacterial antigen-stimulated CD8(+) T cells expressing type 1 [interferon-γ and interleukin-2 (IL-2)] and type 17 (IL-17F) cytokines. We also found that TB-DM is characterized by expanded frequencies of TB antigen-stimulated NK cells expressing type 1 (tumour necrosis factor-α) and type 17 (IL-17A and IL-17F) cytokines. In contrast, CD8(+) T cells were associated with significantly diminished expression of the cytotoxic markers perforin, granzyme B and CD107a both at baseline and following antigen or anti-CD3 stimulation, while NK cells were associated with significantly decreased antigen-stimulated expression of CD107a only. This was not associated with alterations in CD8(+) T-cell or NK cell numbers or subset distribution. Therefore, our data suggest that pulmonary TB complicated with type 2 DM is associated with an altered repertoire of cytokine-producing and cytotoxic molecule-expressing CD8(+) T and NK cells, possibly contributing to increased pathology.