Monocyte-driven inflamm-aging reduces intestinal barrier function in females.

BACKGROUND: The intestinal barrier encompasses physical and immunological components that act to compartmentalize luminal contents, such as bacteria and endotoxins, from the host. It has been proposed that an age-related decline of intestinal barrier function may allow for the passage of luminal contents into the bloodstream, triggering a low-grade systemic inflammation termed inflamm-aging. Although there is mounting evidence to support this hypothesis in model species, it is unclear if this phenomenon occurs in humans. In addition, despite being well-established that biological sex impacts aging physiology, its influence on intestinal barrier function and inflamm-aging has not been explored. RESULTS: In this study, we observed sex differences in markers of intestinal barrier integrity, where females had increased epithelial permeability throughout life as compared to males. With age, females had an age-associated increase in circulating bacterial products and metabolites such as LPS and kynurenine, suggesting reduced barrier function. Females also had age-associated increases in established markers of inflamm-aging, including peripheral blood monocytes as well as TNF and CRP. To determine if impaired barrier function was driving inflamm-aging, we performed a mediation analysis. The results show that the loss of intestinal barrier integrity was not the mediator of inflamm-aging in humans. Instead, persistent, low-grade inflammation with age preceded the increase in circulating bacterial products, which we confirmed using animal models. We found, as in humans, that sex modified age-associated increases in circulating monocytes in mice, and that inflammation mediates the loss of intestinal barrier function. CONCLUSION: Taken together, our results suggest that higher basal intestinal permeability in combination with age-associated inflammation, increases circulating LPS in females. Thus, targeting barrier permeability in females may slow the progression of inflamm-aging, but is unlikely to prevent it.

Defining an Ageing-Related Pathology, Disease or Syndrome: International Consensus Statement.

Background: Around the world, individuals are living longer, but an increased average lifespan does not always equate to an increased healthspan. With advancing age, the increased prevalence of ageing-related diseases can have a significant impact on health status, functional capacity, and quality of life. It is therefore vital to develop comprehensive classification and staging systems for ageing-related pathologies, diseases and syndromes. This will allow societies to better identify, quantify, understand, and meet the healthcare, workforce, wellbeing, and socioeconomic needs of ageing populations, while supporting the development and utilisation of interventions to prevent or to slow, halt or reverse the progression of ageing-related pathologies. Methods: The foundation for developing such classification and staging systems is to define the scope of what constitutes an ageing-related pathology, disease or syndrome. To this end, a consensus meeting was hosted by the International Consortium to Classify Ageing-Related Pathologies (ICCARP), on February 19 th , 2024, in Cardiff, UK, and was attended by 150 recognised experts. Discussions and voting were centred on provisional criteria that had been distributed prior to the meeting. The participants debated and voted on these. Each criterion required a consensus agreement of ≥70% for approval. Results: The accepted criteria for an ageing-related pathology, disease or syndrome were: Develops and/or progresses with increasing chronological age.Should be associated with, or contribute to, functional decline, or an increased susceptibility to functional decline.Evidenced by studies in humans. Conclusions: Criteria for an ageing-related pathology, disease or syndrome have been agreed by an international consortium of subject experts. These criteria will now be used by the ICCARP for the classification and ultimately staging of ageing-related pathologies, diseases and syndromes.

Canadian health care providers' and education workers' hesitance to receive original and bivalent COVID-19 vaccines.

BACKGROUND: The demand for COVID-19 vaccines has diminished as the pandemic lingers. Understanding vaccine hesitancy among essential workers is important in reducing the impact of future pandemics by providing effective immunization programs delivered expeditiously. METHOD: Two surveys exploring COVID-19 vaccine acceptance in 2021 and 2022 were conducted in cohorts of health care providers (HCP) and education workers participating in prospective studies of COVID-19 illnesses and vaccine uptake. Demographic factors and opinions about vaccines (monovalent and bivalent) and public health measures were collected in these self-reported surveys. Modified multivariable Poisson regression was used to determine factors associated with hesitancy. RESULTS: In 2021, 3 % of 2061 HCP and 6 % of 3417 education workers reported hesitancy (p < 0.001). In December 2022, 21 % of 868 HCP and 24 % of 1457 education workers reported being hesitant to receive a bivalent vaccine (p = 0.09). Hesitance to be vaccinated with the monovalent vaccines was associated with earlier date of survey completion, later receipt of first COVID-19 vaccine dose, no influenza vaccination, and less worry about becoming ill with COVID-19. Factors associated with hesitance to be vaccinated with a bivalent vaccine that were common to both cohorts were receipt of two or fewer previous COVID-19 doses and lower certainty that the vaccines were safe and effective. CONCLUSION: Education workers were somewhat more likely than HCP to report being hesitant to receive COVID-19 vaccines but reasons for hesitancy were similar. Hesitancy was associated with non-receipt of previous vaccines (i.e., previous behaviour), less concern about being infected with SARS-CoV-2, and concerns about the safety and effectiveness of vaccines for both cohorts. Maintaining inter-pandemic trust in vaccines, ensuring rapid data generation during pandemics regarding vaccine safety and effectiveness, and effective and transparent communication about these data are all needed to support pandemic vaccination programs.

Reassuring humoral and cellular immune responses to SARS-CoV-2 vaccination in participants with systemic sclerosis.

Individuals with systemic sclerosis (SSc) are particularly susceptible to SARS-CoV-2 infections, yet it remains to be determined if they generate humoral and cellular responses comparable to controls following SARS-CoV-2 vaccinations. Herein, we collected blood and serum after second, third, and fourth SARS-CoV-2 vaccinations in patients with SSc and controls. Following each dose, participants with SSc mounted comparable serum anti-RBD IgG, anti-RBD IgA, and spike-specific CD4+ and CD8+T cell responses to those found in controls. At 3 months post dose 2, the frequencies of Th1, Th2, Th17, and Treg spike-specific CD4+T cells in participants with SSc did not differ from controls. At 2-6 weeks post dose 3, participants with SSc displayed reduced frequencies, but not numbers, of Th17-polarized spike-specific CD4+T cells. Thus, participants with SSc did not display significantly weaker humoral or cellular responses to SARS-CoV-2 vaccination than controls, enabling reassurance of vaccine immunogenicity in participants with SSc.

Methotrexate and Tumor Necrosis Factor Inhibitors Independently Decrease Neutralizing Antibodies after SARS-CoV-2 Vaccination: Updated Results from the SUCCEED Study.

Objective: SARS-CoV-2 remains the third most common cause of death in North America. We studied the effects of methotrexate and tumor necrosis factor inhibitor (TNFi) on neutralization responses after COVID-19 vaccination in immune-mediated inflammatory disease (IMID). Methods: Prospective data and sera of adults with inflammatory bowel disease (IBD), rheumatoid arthritis (RA), spondyloarthritis (SpA), psoriatic arthritis (PsA), and systemic lupus (SLE) were collected at six academic centers in Alberta, Manitoba, Ontario, and Quebec between 2022 and 2023. Sera from two time points were evaluated for each subject. Neutralization studies were divided between five laboratories, and each lab's results were analyzed separately using multivariate generalized logit models (ordinal outcomes: absent, low, medium, and high neutralization). Odds ratios (ORs) for the effects of methotrexate and TNFi were adjusted for demographics, IMID, other biologics and immunosuppressives, prednisone, COVID-19 vaccinations (number/type), and infections in the 6 months prior to sampling. The adjusted ORs for methotrexate and TNFi were then pooled in random-effects meta-analyses (separately for the ancestral strains and the Omicron BA1 and BA5 strains). Results: Of 479 individuals (958 samples), 292 (61%) were IBD, 141 (29.4%) were RA, and the remainder were PsA, SpA, and SLE. The mean age was 57 (62.2% female). For both the individual labs and the meta-analyses, the adjusted ORs suggested independent negative effects of TNFi and methotrexate on neutralization. The meta-analysis adjusted ORs for TNFi were 0.56 (95% confidence interval (CI) 0.39, 0.81) for the ancestral strain and 0.56 (95% CI 0.39, 0.81) for BA5. The meta-analysis adjusted OR for methotrexate was 0.39 (95% CI 0.19, 0.76) for BA1. Conclusions: SARS-CoV-2 neutralization in vaccinated IMID was diminished independently by TNFi and methotrexate. As SARS-CoV-2 circulation continues, ongoing vigilance regarding optimized vaccination is required.

COVID-19 vaccine effectiveness among South Asians in Canada.

We evaluated the effectiveness of COVID-19 vaccines among South Asians living in Ontario, Canada compared to non-South Asians and compared the odds of symptomatic COVID-19 infection and related hospitalizations and deaths among non-vaccinated South Asians and non-South Asians. This was a test negative design study conducted in Ontario, Canada between December 14, 2020 and November 15, 2021. All eligible individuals >18 years with symptoms of COVID-19 were subdivided by ethnicity (South Asian vs other) and vaccination status (vaccinated versus not). The primary outcome was vaccine effectiveness as defined by COVID-19 infections, hospitalizations, and deaths, and secondary outcome was the odds of COVID-19 infections, hospitalizations, and death comparing non-vaccinated South Asians to non-vaccinated non-South Asians. 883,155 individuals were included. Among South Asians, two doses of COVID-19 vaccine prevented 93.8% (95% CI 93.2, 94.4) of COVID-19 infections and 97.5% (95% CI 95.2, 98.6) of hospitalizations and deaths. Among non-South Asians, vaccines prevented 86.6% (CI 86.3, 86.9) of COVID-19 infections and 93.1% (CI 92.2, 93.8) of hospitalizations and deaths. Non-vaccinated South Asians had higher odds of symptomatic SARS-CoV-2 infection compared to non-vaccinated non-South Asians (OR 2.35, 95% CI 2.3, 2.4), regardless of their immigration status. COVID-19 vaccines are effective in preventing infections, hospitalizations and deaths among South Asians living in Canada. The observation that non-vaccinated South Asians have higher odds of symptomatic COVID-19 infection warrants further investigation.

Duration of Postvaccination Neutralizing Antibodies to SARS-CoV-2 and Medication Effects: Results from the Safety and Immunogenicity of COVID-19 Vaccination in Systemic Immune-Mediated Inflammatory Diseases Cohort Study.

OBJECTIVE: In the face of the ongoing circulation of SARS-CoV-2, the durability of neutralization post-COVID-19 vaccination in immune-mediated inflammatory disease (IMID) is a key issue, as are the effects of medications. METHODS: Adults (n = 112) with inflammatory bowel disease, psoriasis/psoriatic arthritis, rheumatoid arthritis, spondylarthritis, and systemic lupus were recruited from participating Canadian medical centers from 2021 to 2023. We focused on log-transformed neutralization (lentivirus methods) as a continuous outcome, with separate models for wild-type and Omicron strains BA.1 and BA.5. RESULTS: Compared with 30 to 120 days postvaccination, subsequent periods were associated with greater neutralization in unadjusted models for wild-type, BA.1, and BA.5 strains and against the BA.1 strain in adjusted models. Rituximab was associated with lower neutralization for the BA.1 strain in adjusted models, with a similar trend for BA.5. In methotrexate users, there were trends for less neutralization of BA.1 and BA.5 in all unadjusted models, whereas in adjusted models, there was significantly lower neutralization only for the wild type. Three or more doses and Omicron-specific vaccines were both independently associated with better neutralization ability for all three strains. A COVID-19 infection within six months before sampling was associated with higher neutralization of wild type and BA.1 in adjusted analyses. Anti-tumor necrosis factor agents were associated with lower neutralization ability for BA.5 in adjusted analyses. CONCLUSION: Neutralization responses in immunosuppressed individuals with IMID were durable over time and were augmented by more than three doses and Omicron-specific vaccines. Less neutralization was seen with certain medications. Our work clarifies the joint effects of vaccine history, infection, and medications on COVID-19 immunity.

A Scoping Review of the Relationship Between Maternal BMI and Offspring Incidence of Respiratory Infection: Where Do We Go From Here?

Introduction: Pregnancy complications, including high maternal BMI, are associated with altered early development and child health outcomes. A growing body of work links the prenatal environment, specifically maternal BMI, with respiratory infections in offspring. In this rapid review, the authors review the literature supporting the hypothesis that high maternal BMI during pregnancy is associated with childhood respiratory infection incidence. Methods: The authors employed systematic search criteria in known databases-EMBASE, EMCARE, MEDLINE, CINAHL, and PsychINFO-searching from inception to January 2023. Included were primary research studies that involved (1) human pregnancy, (2) pregravid or gestational overweight or obesity, and (3) childhood respiratory infection with or without hospitalization. Results: Only 7 population-based cohort studies met the criteria, investigating maternal BMI as an exposure and childhood respiratory infection as an outcome (age 6 months to 18 years). Therefore, the authors conducted a qualitative analysis, and outcomes were reported. The authors found that >85% of the albeit few published studies support the hypothesis that maternal BMI may have independent and profound consequences on respiratory infection risk across childhood. Discussion: This area of research needs large-scale, well-controlled studies to better understand the relationship between maternal BMI and childhood respiratory infection. Possible resources such as cohort catalogs and combined databases are discussed. These findings add to the growing evidence that early environmental factors influence lifelong respiratory health. By incorporating a life course approach to infectious disease risk, policy makers can put this research to work and target health vulnerabilities before they arise.

Nasal cathelicidin is expressed in early life and is increased during mild, but not severe respiratory syncytial virus infection.

Respiratory syncytial virus is the major cause of acute lower respiratory tract infections in young children, causing extensive mortality and morbidity globally, with limited therapeutic or preventative options. Cathelicidins are innate immune antimicrobial host defence peptides and have antiviral activity against RSV. However, upper respiratory tract cathelicidin expression and the relationship with host and environment factors in early life, are unknown. Infant cohorts were analysed to characterise early life nasal cathelicidin levels, revealing low expression levels in the first week of life, with increased levels at 9 months which are comparable to 2-year-olds and healthy adults. No impact of prematurity on nasal cathelicidin expression was observed, nor were there effects of sex or birth mode, however, nasal cathelicidin expression was lower in the first week-of-life in winter births. Nasal cathelicidin levels were positively associated with specific inflammatory markers and demonstrated to be associated with microbial community composition. Importantly, levels of nasal cathelicidin expression were elevated in infants with mild RSV infection, but, in contrast, were not upregulated in infants hospitalised with severe RSV infection. These data suggest important relationships between nasal cathelicidin, upper airway microbiota, inflammation, and immunity against RSV infection, with interventional potential.

Chronic TNF in the aging microenvironment exacerbates Tet2 loss-of-function myeloid expansion.

ABSTRACT: Somatic mutations in the TET2 gene occur more frequently with age, imparting an intrinsic hematopoietic stem cells (HSCs) advantage and contributing to a phenomenon termed clonal hematopoiesis of indeterminate potential (CHIP). Individuals with TET2-mutant CHIP have a higher risk of developing myeloid neoplasms and other aging-related conditions. Despite its role in unhealthy aging, the extrinsic mechanisms driving TET2-mutant CHIP clonal expansion remain unclear. We previously showed an environment containing tumor necrosis factor (TNF) favors TET2-mutant HSC expansion in vitro. We therefore postulated that age-related increases in TNF also provide an advantage to HSCs with TET2 mutations in vivo. To test this hypothesis, we generated mixed bone marrow chimeric mice of old wild-type (WT) and TNF-/- genotypes reconstituted with WT CD45.1+ and Tet2-/- CD45.2+ HSCs. We show that age-associated increases in TNF dramatically increased the expansion of Tet2-/- cells in old WT recipient mice, with strong skewing toward the myeloid lineage. This aberrant myelomonocytic advantage was mitigated in old TNF-/- recipient mice, suggesting that TNF signaling is essential for the expansion Tet2-mutant myeloid clones. Examination of human patients with rheumatoid arthritis with clonal hematopoiesis revealed that hematopoietic cells carrying certain mutations, including in TET2, may be sensitive to reduced TNF bioactivity following blockade with adalimumab. This suggests that targeting TNF may reduce the burden of some forms of CHIP. To our knowledge, this is the first evidence to demonstrate that TNF has a causal role in driving TET2-mutant CHIP in vivo. These findings highlight TNF as a candidate therapeutic target to control TET2-mutant CHIP.