Use of Antiplatelet Agents and Survival of Tuberculosis Patients: A Population-Based Cohort Study

Toll-like receptor and matrix metalloproteinase single-nucleotide polymorphisms, haplotypes, and polygenic risk score differentiated between tuberculosis disease and infection

OBJECTIVES

The association of toll-like receptors (TLRs) and matrix metalloproteinases (MMPs) single-nucleotide polymorphisms (SNPs) among latent tuberculosis (TB) infection and active TB remained less studied.

METHODS

We recruited participants with TB disease (active TB) (n = 400) and TB infection (latent TB infection) (n = 203) in this study. We genotyped SNPs in TLR1, TLR2, TLR4, MMP1, MMP8, MMP9, MMP12, and tissue inhibitor of MMP2. Single-variant analysis and haplotype analysis were performed, and a polygenic risk score (PRS) was created.

RESULTS

We found that SNPs in TLR1 (rs5743580, rs5743551), TLR2 (rs3804100), and MMP8 (rs2508383) were associated with different TB disease status risks. TLR1 rs5743580 was associated with a higher risk of TB disease status in genotypic, recessive, and additive models. TLR2 rs3804100 polymorphisms demonstrated significant association with TB disease status in genotypic, dominant, and additive models. In the haplotype analysis, the TLR1 haplotype was associated with a higher risk of TB disease, and the MMP12 haplotype was associated with a lower risk of TB disease. A PRS using 3 SNPs was associated with a higher risk of TB disease.

CONCLUSION

This study revealed that SNP variants in TLR1, TLR2, and MMP8 differed among TB infection and disease. Haplotypes and PRS could potentially help predict TB disease status.

High levels of PF4, VEGF-A, and classical monocytes correlate with the platelets count and inflammation during active tuberculosis

Platelets play a major role in coagulation and hemostasis; evidence supports the hypothesis that they also contribute to immunological processes. Increased platelet counts have been associated with poor prognosis in tuberculosis (TB). Platelet–monocyte aggregates have been reported in patients with TB, but it is still unclear if only one monocyte subpopulation is correlated to the platelet count; moreover, the platelet–monocyte axis has not been studied during latent tuberculosis (LTB). In this study, mononuclear cells and plasma were obtained from patients diagnosed with active drug-sensitive TB (DS-TB, n = 10) and LTB (n = 10); cytokines and growth factors levels associated to platelets were evaluated, and correlations with monocyte subpopulations were performed to identify a relationship between them, as well as an association with the degree of lung damage. Our data showed that, compared to LTB, DS-TB patients had an increased frequency of platelets, monocytes, and neutrophils. Although DS-TB patients showed no significant difference in the frequency of classical and non-classical monocytes, the classical monocytes had increased CD14 intensity of expression and frequency of TLR-2+. Furthermore, the plasma levels of angiogenic factors such as vascular endothelial growth factor (VEGF-A), platelet-derived growth factor (PDGF-BB), and platelet factor-4 (PF4), and pro-inflammatory cytokines like interleukin 6 (IL-6), interleukin 1 beta (IL-1β), and interferon-γ-inducible protein 10 (IP-10) were increased in DS-TB patients. In addition, PF-4 and VEGF-A correlated positively with the frequency of classical monocytes and the platelet count. Using a principal component analysis, we identified four groups of DS-TB patients according to their levels of pro-inflammatory cytokines, angiogenic factors, and degree of lung damage. This study establishes that there is a correlation between VEGF-A and PF4 with platelets and classical monocytes during active TB, suggesting that those cell subpopulations are the major contributors of these molecules, and together, they control the severity of lung damage by amplification of the inflammatory environment.

Host-directed therapies in pulmonary tuberculosis: Updates on anti-inflammatory drugs

Tuberculosis (TB) is a lethal disease and remains one of the top ten causes of mortality by an infectious disease worldwide. It can also result in significant morbidity related to persistent inflammation and tissue damage. Pulmonary TB treatment depends on the prolonged use of multiple drugs ranging from 6 months for drug-susceptible TB to 6-20 months in cases of multi-drug resistant disease, with limited patient tolerance resulting from side effects. Treatment success rates remain low and thus represent a barrier to TB control. Adjunct host-directed therapy (HDT) is an emerging strategy in TB treatment that aims to target the host immune response to Mycobacterium tuberculosis in addition to antimycobacterial drugs. Combined multi-drug treatment with HDT could potentially result in more effective therapies by shortening treatment duration, improving cure success rates and reducing residual tissue damage. This review explores the rationale and challenges to the development and implementation of HDTs through a succinct report of the medications that have completed or are currently being evaluated in ongoing clinical trials.

Diabetes-Associated Susceptibility to Tuberculosis: Contribution of Hyperglycemia vs. Dyslipidemia

Diabetes is a major risk factor for tuberculosis (TB). Diabetes increases the risk of the progression from latent tuberculosis infection (LTBI) to active pulmonary TB and TB patients with diabetes are at greater risk of more severe disease and adverse TB treatment outcomes compared to TB patients without co-morbidities. Diabetes is a complex disease, characterised not only by hyperglycemia but also by various forms of dyslipidemia. However, the relative contribution of these underlying metabolic factors to increased susceptibility to TB are poorly understood. This review summarises our current knowledge on the epidemiology and clinical manifestation of TB and diabetes comorbidity. We subsequently dissect the relative contributions of body mass index, hyperglycemia, elevated cholesterol and triglycerides on TB disease severity and treatment outcomes. Lastly, we discuss the impact of selected glucose and cholesterol-lowering treatments frequently used in the management of diabetes on TB treatment outcomes.

Platelet Activation and the Immune Response to Tuberculosis

In 2019 10 million people developed symptomatic tuberculosis (TB) disease and 1.2 million died. In active TB the inflammatory response causes tissue destruction, which leads to both acute morbidity and mortality. Tissue destruction in TB is driven by host innate immunity and mediated via enzymes, chiefly matrix metalloproteinases (MMPs) which are secreted by leukocytes and stromal cells and degrade the extracellular matrix. Here we review the growing evidence implicating platelets in TB immunopathology. TB patients typically have high platelet counts, which correlate with disease severity, and a hypercoagulable profile. Platelets are present in human TB granulomas and platelet-associated gene transcripts are increased in TB patients versus healthy controls. Platelets most likely drive TB immunopathology through their effect on other immune cells, particularly monocytes, to lead to upregulation of activation markers, increased MMP secretion, and enhanced phagocytosis. Finally, we consider current evidence supporting use of targeted anti-platelet agents in the treatment of TB due to growing interest in developing host-directed therapies to limit tissue damage and improve treatment outcomes. In summary, platelets are implicated in TB disease and contribute to MMP-mediated tissue damage via their cellular interactions with other leukocytes, and are potential targets for novel host-directed therapies.

Host-directed therapy to combat mycobacterial infections

Upon infection, mycobacteria, such as Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM), are recognized by host innate immune cells, triggering a series of intracellular processes that promote mycobacterial killing. Mycobacteria, however, have developed multiple counter‐strategies to persist and survive inside host cells. By manipulating host effector mechanisms, including phagosome maturation, vacuolar escape, autophagy, antigen presentation, and metabolic pathways, pathogenic mycobacteria are able to establish long‐lasting infection. Counteracting these mycobacteria‐induced host modifying mechanisms can be accomplished by host‐directed therapeutic (HDT) strategies. HDTs offer several major advantages compared to conventional antibiotics: (a) HDTs can be effective against both drug‐resistant and drug‐susceptible bacteria, as well as potentially dormant mycobacteria; (b) HDTs are less likely to induce bacterial drug resistance; and (c) HDTs could synergize with, or shorten antibiotic treatment by targeting different pathways. In this review, we will explore host‐pathogen interactions that have been identified for Mtb for which potential HDTs impacting both innate and adaptive immunity are available, and outline those worthy of future research. We will also discuss possibilities to target NTM infection by HDT, although current knowledge regarding host‐pathogen interactions for NTM is limited compared to Mtb. Finally, we speculate that combinatorial HDT strategies can potentially synergize to achieve optimal mycobacterial host immune control.

Survival After Treatable Hepatocellular Carcinoma Recurrence in Liver Recipients: A Nationwide Cohort Analysis

Background

Survival after post-transplant recurrence of HCC is dismal, and almost all treatments for recurrent HCC are off-labeled, without an extensive large-scale analysis. We aimed to delineate their post-recurrence courses and define benchmarks for comparing future treatment effectiveness.

Methods

Three national databases, including health insurance, catastrophic illness, and the cause of death, were linked for cohort establishment and data collection during the period from 2005 to 2016. Patients with HCC recurrence ≥6 months after transplant surgery and under treatment were recruited for survival analysis. Selection of treatment strategies for HCC recurrence after liver transplant was based on the same criteria for those without liver transplant.

Results

Of 2,123 liver transplant recipients, 349 developed HCC recurrence ≥6 months after liver transplant, and the median recurrence time was 17.8 months post-transplant. Within 2 years of treatment, 61% patients showed recurrence (early recurrence group), and survival in these patients was poorer than in the late recurrence group. According to a multivariable analysis, the transplant era before 2008 and radiofrequency ablation were associated with good prognosis, whereas receiving sorafenib and radiotherapy was associated with poor prognosis. The effect of transplant era became insignificant after stratification by recently receiving pretransplant transarterial chemoembolization.

Conclusion

Timing of recurrence and interventions used were associated with the outcomes of patients with post-transplant HCC recurrence. These data provide the benchmark and indicate the critical period and high-risk factors for further therapeutic trial consideration.

Treatment Options of First-Line Tyrosine Kinase Inhibitors and Subsequent Systemic Chemotherapy Agents for Advanced EGFR Mutant Lung Adenocarcinoma Patients: Implications From Taiwan Cancer Registry Cohort

Objectives

Large-scale, population-based real-world studies on the treatment outcomes of first-line tyrosine kinase inhibitors (TKIs) and subsequent systemic chemotherapy agents for lung adenocarcinoma (with activating epidermal growth factor receptor [EGFR] mutations) remain limited.

Materials and Methods

From March 2014 to December 2016, patients with advanced lung adenocarcinoma, identified from the Taiwan Cancer Registry were included in this study if they received any of the three TKIs as first-line treatment. The primary outcome was overall survival (OS). The secondary outcome was time-to-treatment discontinuation (TTD).

Results

A total of 4,889 patients (median age: 67 years and two-thirds with distant metastasis) were recruited (1,778 gefitinib, 1,599 erlotinib, and 1,512 afatinib users). A 1:1 propensity score (PS)-matched cohorts of 1,228 afatinib/erlotinib and 1054 afatinib/gefitinib was created. After PS matching, it was found that afatinib was not associated with better OS (afatinib vs. erlotinib, HR: 0.96, 95% CI: 0.86–1.07; afatinib vs. gefitinib, HR: 0.91, 95% CI: 0.81–1.02). In the subgroup analysis, afatinib demonstrated a survival benefit in patients with active smoking (afatinib vs. erlotinib, HR: 0.69, 95% CI: 0.51–0.93; afatinib vs. gefitinib, HR: 0.67, 95% CI: 0.48–0.94) and ECOG > 1 (afatinib vs. erlotinib, HR: 0.79, 95% CI: 0.63–0.99; afatinib vs. gefitinib, HR: 0.78, 95% CI: 0.62–0.98). A total of 41.1% (n = 1992) of first-line TKI users received subsequent chemotherapy. Among the three TKI groups, pemetrexed usage was associated with better OS compared with other chemotherapy agents, with the exception of gemcitabine in the afatinib and gefitinib groups. Pemetrexed and gemcitabine had the longest TTD of 3–4 months.

Conclusions

Among patients with EGFR mutant lung adenocarcinoma, afatinib use may not provide longer OS compared with first-generation TKIs. Afatinib may be preferably considered among patients with active smoking and should not be withheld among those with worse performance status. With 40% of patients receiving subsequent chemotherapy, pemetrexed may be the preferred agent, while gemcitabine can be a reasonable alternative.

Aspirin enhances the clinical efficacy of anti-tuberculosis therapy in pulmonary tuberculosis in patients with type 2 diabetes mellitus

Background: Tuberculosis in patients with diabetes mellitus is characterised by rapid disease progression, poor treatment efficacy, poor prognosis and poses a new challenge in tuberculosis treatment and control.Methods: Patients with pulmonary TB and type 2 DM were recruited at Yijishan Hospital of Wannan Medical College. A total of 348 patients were randomly assigned to two groups. The aspirin group (aspirin + TB/DM) included 174 patients who received anti-TB therapy and enteric-coated aspirin tablets (100 mg/tablet). The control group (placebo + TB/DM) included 174 patients who received anti-TB therapy and enteric-coated placebo tablets (an identical tablet containing no drug). Eighty-two patients in the aspirin group and 86 in the control group completed the trial and were included in the analysis. Clinical characteristics, laboratory test results, imaging data and side effects of aspirin were monitored.Results: Aspirin treatment affect certain signs and symptoms. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were lower in the aspirin group than in the control group after treatment (Both p = .000). The sputum-negative conversion rate was 86.7% in the aspirin group, significantly higher than in the control group (53.8%) (p = .031). After two months of treatment, the differences in the number of cases with cavities, the number of cavities, and maximum diameter of cavities in the aspirin group were statistically significant (p = .003, p = .023 and p = .015 respectively).Conclusion: Our findings suggest that aspirin may improve treatment in patients with pulmonary TB and type 2 DM.

Host-directed therapies targeting the tuberculosis granuloma stroma

Mycobacteria have co-evolved with their hosts resulting in pathogens adept at intracellular survival. Pathogenic mycobacteria actively manipulate infected macrophages to drive granuloma formation while subverting host cell processes to create a permissive niche. Granuloma residency confers phenotypic antimicrobial resistance by physically excluding or neutralising antibiotics. Host-directed therapies (HDTs) combat infection by restoring protective immunity and reducing immunopathology independent of pathogen antimicrobial resistance status. This review covers innovative research that has discovered ‘secondary’ symptoms of infection in the granuloma stroma are actually primary drivers of infection and that relieving these stromal pathologies with HDTs benefits the host. Advances in our understanding of the relationship between tuberculosis and the host vasculature, haemostatic system and extracellular matrix reorganisation are discussed. Preclinical and clinical use of HDTs against these stromal targets are summarised.