Posts

Impact of DM on TB prevention, diagnosis, and treatment from an immunologic perspective [TB0093]

One in every ten adults is a diabetic (DM) patient. Long-term hyperglycemia in DM patients leads to decreased immune cell numbers and function, increasing the incidence of tuberculosis (TB). Chronic hyperglycemia severely impairs the function of innate immune cells, affecting processes such as monocyte differentiation into macrophages and dendritic cells. This impairs the recruitment, recognition, phagocytosis, and antigen presentation functions of macrophages and reduces the frequency of dendritic cells and natural killer cells. Additionally, hyperglycemia increases the inflammatory response of neutrophils, which exacerbates bacterial load. Chronic hyperglycemia may delay the activation of adaptive immune cells, including CD4+ and CD8+ T cells. CD4+ T cells are crucial in anti-tuberculosis immunity, promoting the proliferation of T lymphocytes and macrophage activation via interferon-gamma (IFN-γ) secretion. However, high blood glucose levels can delay CD4+ T cell activation, reducing
Post a Comment
Read more

Impact of DM on immunity to LTBI [TB0092]

Latent tuberculosis infection (LTBI) is characterized by an infection with Mycobacterium tuberculosis (M.tb) without symptoms of active TB. M.tb's success lies in its ability to remain asymptomatic in a latent state, reactivating only in a minority over months, years, or even decades. The risk of reactivation varies with age at infection and any concurrent health conditions that promote TB progression. With about one-fourth of the global population estimated to have LTBI, this large pool serves as a reservoir for TB re-emergence. See also:  https://tbreadingnotes.blogspot.com/2024/07/population-health-impact-and-cost.html Effective control of M.tb involves T cells, which aid macrophages in granuloma formation, tackling M.tb antigens. CD4+ T cells, in particular, release cytokines and chemokines with macrophage assistance, also supporting CD8+ T cell, DURT, and B cell activities. Both lymphoid and myeloid innate immune cells are crucial for the host’s defense against M.tb. However,
Post a Comment
Read more

Temporal trends in mortality of TB attributable to HFPG in China [TB0091]

TB patients with diabetes or hyperglycemia face a higher likelihood of experiencing more severe disease and unfavorable treatment outcomes compared to those without co-morbidities. Long-term elevated blood glucose levels can impair immune cells crucial for combating TB bacteria, weakening the immune response and enabling TB bacteria to multiply and spread throughout the body, thereby increasing the risk of developing active TB. Additionally, diabetes and hyperglycemia can reduce the body's ability to effectively treat TB infections. See also:  https://tbreadingnotes.blogspot.com/2024/07/exposure-to-secondhand-smoke-and-risk.html In China, the age-standardized mortality rates (ASMRs) for TB related to hyperglycemia were lower than the global average. Although men showed higher TB mortality rates, the reduction in mortality was smaller in men compared to women. Notably,  high fasting plasma glucose (HFPG) -related TB mortality initially increased and then decreased with age, with the
Post a Comment
Read more

Glycemic control in tuberculosis [TB0090]

In low and moderate TB incidence countries, TB often concentrates in specific groups, notably those with diabetes. In Taiwan, diabetes mellitus (DM) is the leading risk factor for pulmonary TB. After adjusting for confounders, type 2 DM is an independent risk factor for TB nationwide, though the association is stronger for type 1 DM. Poor glycemic control can increase the hazard ratio for TB in adults under 65, with men and individuals aged 55–64 at greater risk. TB patients with heart failure, ischemic heart disease, stroke, hypertension, dyslipidemia, chronic kidney disease, and liver disease are more likely to have DM. Interestingly, obesity does not increase TB risk despite its link to diabetes. TB incidence and mortality have decreased in Taiwan, yet DM remains the fifth leading cause of death. In newly diagnosed TB patients, those with DM experience higher mortality rates. Proper TB treatment has been shown to improve glycemic control, possibly due to TB-induced hyperglycemia thr
Post a Comment
Read more

Recent advances in the treatment of tuberculosis [TB0089]

·   Standard DS-TB Treatment : The traditional DS-TB treatment consists of a 2-month intensive phase with rifampicin, isoniazid, and pyrazinamide, followed by a 4-month continuation phase with rifampicin and isoniazid. Recently, a 4-month regimen including rifapentine, isoniazid, pyrazinamide, and moxifloxacin was conditionally recommended by WHO for eligible patients aged 12 and above. See also:  https://tbreadingnotes.blogspot.com/2024/07/the-effect-of-type-2-dm-on-presentation.html ·   Isoniazid-Resistant TB : WHO recommends a 6-month regimen of rifampicin, ethambutol, pyrazinamide, and levofloxacin for isoniazid-resistant but rifampicin-susceptible TB. Adjustments, such as limiting pyrazinamide to the first 2 months, may be made based on individual factors, although evidence for these variations is limited. ·   Shortened MDR/RR-TB Treatment : WHO recommends a shorter 9–12 month all-oral regimen for MDR/RR-TB without fluoroquinolone resistance, using bedaquiline and potentially line
Post a Comment
Read more

LTBI in health-care workers in the government sector in Brunei Darussalam [TB0088]

The annual incidence rate of LTBI in health-care workers in the government sector in Brunei Darussalam ranged from 8.1 to 24.6, with an average of 14.6 over the 4-year period. When comparing treatment acceptance among subgroups, only gender showed statistical significance, with females demonstrating significantly higher treatment acceptance. Syafiq, N.J.M., Trivedi, A.A., Lai, A., Fontelera, M.P.A. and Lim, M.A., 2023. Latent tuberculosis infection in health-care workers in the government sector in Brunei Darussalam: A cross-sectional study. Journal of Integrative Nursing, 5(3), pp.197-202. https://journals.lww.com/jinm/fulltext/2023/05030/latent_tuberculosis_infection_in_health_care.6.aspx  
Post a Comment
Read more

Associations between type 1 DM and pulmonary TB [TB0087]

Observational studies on diabetes and PTB (pulmonary tuberculosis) are impacted by reverse causality, confounding factors, and lack of specification regarding diabetes phenotypes, particularly between T1DM and T2DM. T1DM is associated with metabolic disorders, such as disturbed glucose and lipid metabolism, obesity, and a higher susceptibility to PTB infections. An estimated 7.5% of TB cases are linked to poor glycemic control. PTB patients often exhibit lower HDL-C, LDL-C, and total cholesterol levels. There is a log-linear relationship between BMI and TB incidence, with TB incidence decreasing by about 14% per unit increase in BMI. Mendelian Randomization (MR) uses genetic variants as instrumental variables to clarify causal relationships, reducing biases from confounders and reverse causality. MR analysis revealed: A positive genetic association between T1DM and PTB. HDL-C genetic predisposition correlates with increased PTB risk. No causal links between PTB and other T1DM-related t
Post a Comment
Read more

Population-based mass TB screening intervention among persons with DM

·   Technology for TB Control : While the technology to control TB exists, it is generally underused. ·   DOTS (Directly Observed Treatment, Short-course) : Originally referred to directly observed treatment with short-course chemotherapy. Now a broader public health strategy with five key elements: Political commitment . Case detection through sputum smear microscopy, mostly among self-referring, symptomatic patients. Standard short-course chemotherapy with supportive patient management, including DOT. Reliable drug supply system . Standardized recording and reporting system , including treatment outcome evaluations. ·   MDG Framework for TB Control : Comprises two DOTS-focused measures: Case detection . Treatment success . Includes three impact measures applicable to TB control in general: Incidence . Prevalence . Deaths . Promotes epidemiologica
Post a Comment
Read more

Impact of diabetes on tuberculosis and MDRTB susceptibility

There is a significant association between diabetes mellitus (DM) and multidrug-resistant tuberculosis (MDR-TB). TB patients without DM have a lower risk of developing MDR-TB compared to those with DM. Factors contributing to MDR-TB emergence in TB patients with DM include: Impaired immune function Altered microbial genomics Uncontrolled glucose levels, increasing susceptibility to MDR-TB Compromised phagocytic activity and reduced chemotactic response Increased oxidative species and microbe proliferation Altered drug disposition Higher likelihood of non-adherence to treatment TB patients with DM also experience higher treatment failure rates compared to those without DM. Most information on these associations is based on self-reported data or patient health records, which may introduce assessment errors Rehman Au, Khattak M, Mushtaq U, Latif M, Ahmad I, Rasool MF, Shakeel S, Hayat K, Hussain R, Alhazmi GA, Alshomrani AO, Alalawi MI, Alghamdi S, Imam MT, Almarzoky Abuhussain SS, Khayya
Post a Comment
Read more

Quantifying the global number of tuberculosis survivors [TB0084]

·   Increased Health Risks for Tuberculosis Survivors : Higher likelihood of recurrent tuberculosis and increased all-cause mortality, regardless of treatment adequacy. Increased risk of chronic respiratory diseases, with many survivors experiencing abnormal spirometry, chronic symptoms, and impaired lung function (such as low forced vital capacity and reduced forced expiratory volume). Elevated risk of mortality, cardiovascular disease, and hospitalizations due to respiratory issues. Reduction in health-related quality of life, exercise tolerance, and increased social stigma and economic challenges post-treatment. See also: Lin TB Lab ·   Social and Economic Impacts : Social stigma may persist, leading to isolation, diminished marriage prospects, and possible divorce. Financial strain from medical costs and income loss during treatment can deepen poverty, potentially affecting family members, particula
Post a Comment
Read more