Long-term exposure to outdoor air pollution and the risk of development of rheumatoid arthritis: A systematic review and meta-analysis

Advances in local drug delivery technologies for improved rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by an inflammatory microenvironment and cartilage erosion within the joint cavity. Currently, antirheumatic agents yield significant outcomes in RA treatment. However, their systemic administration is limited by inadequate drug retention in lesion areas and non-specific tissue distribution, reducing efficacy and increasing risks such as infection due to systemic immunosuppression. Development in local drug delivery technologies, such as nanostructure-based and scaffold-assisted delivery platforms, facilitate enhanced drug accumulation at the target site, controlled drug release, extended duration of the drug action, reduced both dosage and administration frequency, and ultimately improve therapeutic outcomes with minimized damage to healthy tissues. In this review, we introduced pathogenesis and clinically used therapeutic agents for RA, comprehensively summarized locally administered nanostructure-based and scaffold-assisted drug delivery systems, aiming at improving the therapeutic efficiency of RA by alleviating the inflammatory response, preventing bone erosion and promoting cartilage regeneration. In addition, the challenges and future prospects of local delivery for clinical translation in RA are discussed.

Molecular mechanisms of environmental pollutant-induced cartilage damage: from developmental disorders to osteoarthritis

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity.

Ambient fine particulate matter is associated with daily outpatient visits for ankylosing spondylitis: A time-series analysis in Beijing, China

Exposure to ambient fine particulate matter (PM2.5) has a great impact on human body's immune system, but the correlation between PM2.5 and ankylosing spondylitis has not yet been clarified. We extracted 58,600 outpatient visits for ankylosing spondylitis from the Beijing Medical Claim Data for Employees database from 2010 to 2017. The percentage of outpatient visits following PM2.5 concentrations was estimated using generalized additive models with Poisson connections. Increase by 10 μ g/m3, PM2.5 is associated with daily outpatient visits for ankylosing spondylitis. In this test, the average concentration of PM2.5 was 86.8 ± 74.3 μ g/m3. For every 10 μg/m3 increase in PM2.5 concentration, there was a 0.34% (95% CI, 0.26-0.42%) increase in the risk of patients who visited the doctor on the same day. Females and younger patients were most susceptible to the impact of PM2.5 exposure (P＜0.05). This study revealed the relationship between exposure to PM2.5 and ankylosing spondylitis, and future research can further confirm this finding and explore the potential mechanisms.

Exposure to air pollutants and rheumatoid arthritis biomarkers: A scoping review

INTRODUCTION

Rheumatoid arthritis (RA) is a common autoimmune disease with a complex and poorly understood etiology that includes genetic, hormonal, and environmental factors.

OBJECTIVE

Our objective was to assess current literature that investigated the association between exposure to environmental and occupational air pollutants and RA-related biomarkers rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA).

DESIGN

PubMed and Web of Science were used to identify epidemiological studies that measured or estimated air pollution and at least one RA biomarker. Information was charted for comparison of evidence, including pollutant(s) studied, exposure assessment, biomarker measurement, analysis method, study population, size, dates, adjustment variables, and findings.

RESULTS

Several common air pollutants (including two mixtures) and a few dozen occupational inhalants were assessed in 13 eligible studies. Associations between industrial sulfur dioxide and particulate matter less than 2.5 µm in diameter with ACPA were observed most frequently, including associations between residential proximity to pollution sources and ACPA positivity. Consistency of associations with other pollutants was either not observed or limited to single studies. Three studies evaluated the modifying impact of SE alleles (a genetic factor associated with RA) and found that pollutant associations were stronger among participants positive for SE alleles.

CONCLUSION

Based on mixed results, there was no consistent link between any single pollutant and RA-related biomarker outcomes. Comparisons across studies were limited by differences in study populations (e.g., by RA status, by sociodemographic groups) and study design (including designs focused on different sources of air pollution, methodological approaches with varying levels of potential exposure misclassification, and assessments of inconsistent biomarker cut-points). However, given that multiple studies reported associations between exposure to air pollution and RA biomarkers, continued exploration utilizing studies that can be designed with a more robust causal framework, including continued consideration of effect modification by genetic status, may be necessary.

Potential roles of air pollutants on the induction and aggravation of rheumatoid arthritis: From cell to bedside studies

Rheumatoid arthritis (RA) is an involving chronic systemic inflammatory disease which mainly affects the joints. Several factors including genetic, environment and infections have been acknowledged as being involved in the pathogenesis and aggravation of RA. Air pollution, particularly particulate matter is widely recognized as a cause of health problems. This review is to summarize and discuss the association between air pollutants and the development or the aggravation of RA based on evidence from in vitro, in vivo and clinical studies. The results from the review found that air pollutants can stimulate immunological processes and stimulate inflammatory mediators and autoantibodies productions, both in intro and in vivo studies. In addition, air pollutants can induce RA and aggravate RA disease activity. Unfortunately, there also are some discrepancies in the results, which might be due to the type cell line and the concentration of air pollutants used in the in vitro and in vivo studies, as well as the concentration and duration of exposure in human studies. These findings suggest that future studies focused on elucidating these mechanisms using advanced techniques and identifying reliable biomarkers to assess individual susceptibility and disease activity should be carried out. Longitudinal studies, intervention strategies, and policy implications also should be explored. A comprehensive understanding on these association will facilitate targeted approaches for prevention and management of air pollutant-induced RA and improve health outcome.

Association between living environmental quality and risk of arthritis in middle-aged and older adults: a national study in China

Background

The association between combined environmental factors and the risk of arthritis is still scarcely studied. The present study performed cross-sectional and cohort studies to explore the association between risk score of living environment quality and the risk of arthritis in middle-aged and older adults in China.

Methods

The study was based on China Health and Retirement Longitudinal Study (CHARLS), and it recruited 17,218 participants in the cross-sectional study and 11,242 participants in the seven-year follow-up study. The living environment quality was measured by household fuel types, household water sources, room temperature, residence types, and ambient concentration of PM2.5. Logistic regression and Cox proportional hazard regression models were utilized to examine the association between the living environment quality and the risk of arthritis. Competing risk models and stratified analyses were applied to further verify our results.

Results

Compared with individuals in the suitable environment group, people who lived in moderate (OR:1.28, 95%CI: 1.14-1.43) and unfavorable environments (OR:1.49, 95%CI:1.31-1.70) showed higher risks of arthritis when considering the multiple living environmental factors (P for trend <0.001) in the cross-sectional analysis. In the follow-up study, similar results (P for trend = 0.021), moderate environment group (HR:1.26, 95%CI:1.01-1.56) and unfavorable environment group (HR: 1.36, 95%CI: 1.07-1.74), were founded.

Conclusion

Inferior living environment might promote the development of arthritis. It is necessary for the public, especially old people, to improve the living environment, which may be the key to the primary prevention of arthritis.

Spatiotemporal analysis and forecasting of air quality in the greater Dhaka region and assessment of a novel particulate matter filtration unit

Bangladesh is one of the most polluted nations in the world, with an average Air Quality Index (AQI) of 161 in 2021; its capital, Dhaka, has the worst air quality of any major city in the world. The present study aims to analyze the spatiotemporal distribution of air quality indicators in the greater Dhaka region, forecast weekly AQI, and assess the performance of a novel particulate matter filtration unit in removing particulate matter. Air quality indicators remained highest during the dry season with an average of 128.5 μm/m^3, while the lowest concentration was found in the monsoon season with an average of 19.096 μm/m³. Analysis revealed a statistically significant annual increasing trend of CO, which was associated with the growing number of brick kilns and usage of high-sulfur diesel. Except for the pre-monsoon AQI, concentrations of both seasonal and yearly AQI and PM_2.5 showed decreasing trend, though predominantly insignificant, demonstrating the improvement in air quality. Prevailing winds influenced the seasonal distribution of tropospheric CO & NO₂. The study also employed a seasonal autoregressive integrated moving average (ARIMA) model to forecast weekly AQI values. ARIMA (3,0,4) (3,1,3) at the 7-periodicity level performed best forecasting the AQI values among all developed models with low root mean square error (RMSE)-29.42 and mean absolute percentage error (MAPE)-13.11 values. The predicted AQI values suggested that the air quality would remain unhealthy for most weeks. The experimental simulation of the particulate matter filtration unit, designed in the shape of a road divider, generated substantial cyclonic motion while maintaining a very minimal pressure drop. In the real-world scenario, using only cyclonic separation and dry deposition, the suggested air filtration system removed 40%, 44%, and 42% of PM_2.5, PM₁₀, and TSP, respectively. Without employing filters, the device removed significant amounts of particulate matter, implying enormous potential to be used in the study area. The study could be useful for policy makers to improve urban air quality and public health in Bangladesh and in other developing countries.

Air pollution exposure and auto-inflammatory and autoimmune diseases of the musculoskeletal system: a review of epidemiologic and mechanistic evidence

Auto-inflammatory and autoimmune diseases of the musculoskeletal system can be perceived as a spectrum of rheumatic diseases, with the joints and connective tissues are eroded severely that progressively develop chronic inflammation and lesion. A wide range of risk factors represented by genetic and environmental factors have been uncovered by population-based surveys and experimental studies. Lately, the exposure to air pollution has been found to be potentially involved in the mechanisms of occurrence or development of such diseases, principally manifest in oxidative stress, local and systemic inflammation, and epigenetic modifications, as well as the mitochondrial dysfunction, which has been reported to participate in the intermediate links. The lungs might serve as a starting area of air pollutants, which would cause oxidative stress-induced bronchial-associated lymphoid tissue (iBALT) to further to influence T, B cells, and the secretion of pro-inflammatory cytokines. The binding of aromatic hydrocarbon receptor (AhR) to the corresponding contaminant ligands tends to regulate the reaction of Th17 and Tregs. Furthermore, air pollution components might spur on immune and inflammatory responses by damaging mitochondria that could interact with and exacerbate oxidative stress and pro-inflammatory cytokines. In this review, we focused on the association between air pollution and typical auto-inflammatory and autoimmune diseases of the musculoskeletal system, mainly including osteoarthritis (OA), rheumatoid arthritis (RA), spondyloarthritis (SpA) and juvenile idiopathic arthritis (JIA), and aim to collate the mechanisms involved and the potential channels. A complete summary and in-depth understanding of the autoimmune and inflammatory effects of air pollution exposure should hopefully contribute new perspectives on how to formulate better public health policies to alleviate the adverse health effects of air pollutants.

Neighborhood infrastructure-related risk factors and non-communicable diseases: a systematic meta-review

BACKGROUND

With rapid urbanization, the urban environment, especially the neighborhood environment, has received increasing global attention. However, a comprehensive overview of the association between neighborhood risk factors and human health remains unclear due to the large number of neighborhood risk factor-human health outcome pairs.

METHOD

On the basis of a whole year of panel discussions, we first obtained a list of 5 neighborhood domains, containing 33 uniformly defined neighborhood risk factors. We only focused on neighborhood infrastructure-related risk factors with the potential for spatial interventions through urban design tools. Subsequently, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic meta-review of 17 infrastructure-related risk factors of the 33 neighborhood risk factors (e.g., green and blue spaces, proximity to major roads, and proximity to landfills) was conducted using four databases, Web of Science, PubMed, OVID, and Cochrane Library, from January 2000 to May 2021, and corresponding evidence for non-communicable diseases (NCDs) was synthesized. The review quality was assessed according to the A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) standard.

RESULTS

Thirty-three moderate-and high-quality reviews were included in the analysis. Thirteen major NCD outcomes were found to be associated with neighborhood infrastructure-related risk factors. Green and blue spaces or walkability had protective effects on human health. In contrast, proximity to major roads, industry, and landfills posed serious threats to human health. Inconsistent results were obtained for four neighborhood risk factors: facilities for physical and leisure activities, accessibility to infrastructure providing unhealthy food, proximity to industry, and proximity to major roads.

CONCLUSIONS

This meta-review presents a comprehensive overview of the effects of neighborhood infrastructure-related risk factors on NCDs. Findings on the risk factors with strong evidence can help improve healthy city guidelines and promote urban sustainability. In addition, the unknown or uncertain association between many neighborhood risk factors and certain types of NCDs requires further research.

Inhalant and Additional Mucosal-Related Environmental Risks for Rheumatoid Arthritis

Rheumatoid arthritis (RA) occurs as the result of a complex interplay of environmental factors in a genetically susceptible individual. There is considerable evidence that the lungs may serve as an initial site of tolerance loss in the generation of RA-related autoimmunity, and several environmental inhalant exposures and lung diseases have been associated with RA risk. There is additional evidence that immune and microbial dysregulation of other mucosal sites, including the oral and gastrointestinal mucosa, may contribute to the development of RA. Epidemiologic evidence linking mucosal exposures to various environmental insults as risk determinants in RA will be reviewed.

Exposure and health: A progress update by evaluation and scientometric analysis

Several hands are now working worldwide to reduce exposure to air pollution, especially in developing nations. Future steps should be determined and classified as possible research solutions and gaps from the massive bulk of research output. Therefore, a scientometric approach has been applied using VOSviewer to show an accurate picture and trend in the mentioned area "Air pollution exposure and health," and its signify issues. According to the proposed study, complete 26,859 documents were retrieved from the database (ISI Web of Science) related to air pollution exposure and health effects during 2018-2022. The mapping analysis is been conducted on the country's collaboration, co-authorship, institutional collaboration, and co-occurrence of keywords. The data collected shows the information about published articles (upward trend) over the years. Based on the citations and publication database, countries like China and the USA play a prominent role in air pollution exposure and health-related research. The study clearly defines the 3 domains of research and 4 major themes that have been currently focused. The case studies related to pollution and its impact on climate and health, studies involving chemical characteristics and management practices, also Hazardous health effects, theme like association of air pollutants, chemical composition and characterization of aerosols, health impacts due to exposure and modelling and analytical approach have been the most researched topics in the past 5 years. The developing and developed countries might potentially change the research network and work structure in order to obtain advancement in the field of Air pollution and enhance measures on exposure and health. The following research attempts to provide insights to the researchers and health sectors by straightening out developments up to date and raveling the research gaps that are needed to be addressed regarding Air pollution health and exposure.

Outdoor air quality and human health: An overview of reviews of observational studies

The epidemiological evidence supporting putative associations between air pollution and health-related outcomes continues to grow at an accelerated pace with a considerable heterogeneity and with varying consistency based on the outcomes assessed, the examined surveillance system, and the geographic region. We aimed to evaluate the strength of this evidence base, to identify robust associations as well as to evaluate effect variation. An overview of reviews (umbrella review) methodology was implemented. PubMed and Scopus were systematically screened (inception-3/2020) for systematic reviews and meta-analyses examining the association between air pollutants, including CO, NO_X, NO₂, O₃, PM₁₀, PM_2.5, and SO₂ and human health outcomes. The quality of systematic reviews was evaluated using AMSTAR. The strength of evidence was categorized as: strong, highly suggestive, suggestive, or weak. The criteria included statistical significance of the random-effects meta-analytical estimate and of the effect estimate of the largest study in a meta-analysis, heterogeneity between studies, 95% prediction intervals, and bias related to small study effects. Seventy-five systematic reviews of low to moderate methodological quality reported 548 meta-analyses on the associations between outdoor air quality and human health. Of these, 57% (N = 313) were not statistically significant. Strong evidence supported 13 associations (2%) between elevated PM_2.5, PM₁₀, NO₂, and SO₂ concentrations and increased risk of cardiorespiratory or pregnancy/birth-related outcomes. Twenty-three (4%) highly suggestive associations were identified on elevated PM_2.5, PM₁₀, O₃, NO₂, and SO₂ concentrations and increased risk of cardiorespiratory, kidney, autoimmune, neurodegenerative, cancer or pregnancy/birth-related outcomes. Sixty-seven (12%), and 132 (24%) meta-analyses were graded as suggestive, and weak, respectively. Despite the abundance of research on the association between outdoor air quality and human health, the meta-analyses of epidemiological studies in the field provide evidence to support robust associations only for cardiorespiratory or pregnancy/birth-related outcomes.

What is the impact of perioperative cerebral oxygen desaturation on postoperative delirium in old population: a systemic review and meta-analysis

BACKGROUND

Perioperative cerebral oxygen saturation (ScO₂) has been reported to associate with postoperative delirium (POD) which is a common postoperative complication, however, the results were inconclusive. Therefore, we aimed to conduct an up-to-date review and meta-analyze the relationship between perioperative ScO₂ and POD.

METHODS

We systematically searched PubMed, Embase and Web of science through January 13, 2022. The pooled results were estimated through a random-effects model meta-analysis and expressed as odds ratios (ORs) and standard mean differences (SMDs), accompanied with 95% confident intervals (CIs).

RESULTS

Finally, of 467 searched articles, ten articles were included. A total of six studies reported the baseline ScO₂ value and the pooled result showed that preoperative baseline ScO₂ was lower in POD groups (SMD = - 0.41, 95% CI - 0.64 to - 0.18). And beyond that, the pooled OR across four literatures about preoperative low ScO₂ on POD was 3.44 (95% CI 1.69, 7.02). In contrast, insignificant differences were detected in baseline/lowest ScO₂ value during intraoperative and postoperative period. Additionally, there were no statistically significant associations for intraoperative and postoperative low ScO₂ effect on POD risk. Meta-regress analysis has found no significant impact factors.

CONCLUSIONS

Based on current evidence, POD patients have a lower ScO₂, and ScO₂ desaturation may increase POD incidence, indicating the role of ScO₂ underlying pathological mechanisms. For generalizability of evidence, we should rely on high-quality, considering more comprehensively longitudinal, interdisciplinary studies.

Health and Clinical Impacts of Air Pollution and Linkages with Climate Change

Air Pollution Impacts and Climate Change LinksAs part of the NEJM Group series on climate change, Keswani and colleagues review the linkages between climate change and air pollution and suggest strategies that clinicians may use to mitigate the adverse health impacts of air pollution.

Polymer nanotherapeutics: A versatile platform for effective rheumatoid arthritis therapy

Rheumatoid arthritis is an aggressive and severely debilitating disorder that is characterized by joint pain and cartilage damage. It restricts mobility in patients, leaving them unable to carry out simple tasks. RA presents itself with severe lasting pain, swelling and stiffness in the joints and may cause permanent disability in patients. Treatment regimens currently employed for rheumatoid arthritis revolve around keeping clinical symptoms like joint pain, inflammation, swelling and stiffness at bay. The current therapeutic interventions in rheumatoid arthritis involve the use of non-steroidal anti-inflammatory drugs, glucocorticoids, disease-modifying anti-rheumatic drugs and newer biological drugs that are engineered for inhibiting the expression of pro-inflammatory mediators. These conventional drugs are plagued with severe adverse effects because of their higher systemic distribution, lack of specificity and higher doses. Oral, intra-articular, and intravenous routes are routinely used for drug delivery which is associated with decreased patient compliance, high cost, poor bioavailability and rapid systemic clearance. All these drawbacks have enticed researchers to create novel strategies for drug delivery, the main approach being nanocarrier-based systems. In this article, we aim to consolidate the remarkable contributions of polymeric carrier systems including microneedle technology and smart trigger-responsive polymeric carriers in the management of rheumatoid arthritis along with its detailed pathophysiology. This review also briefly describes the safety and regulatory aspects of polymer therapeutics.

Association between Exposure to Ambient Air Pollution and the Risk of Rheumatoid Arthritis in Taiwan: A Population-Based Retrospective Cohort Study

Background: The association between ambient air pollution (AAP) and the risk of Rheumatoid arthritis (RA) remains debatable. We conducted a population-based cohort study to investigate the association between exposure to AAP and the risk of RA in Taiwan. Methods: We analyzed and combined the longitudinal Health Insurance Database (LHID) and the Taiwan Air Quality-Monitoring Database (TAQMD), which were in line with the residential areas. We calculated the RA incidence rates per 10,000 person-years exposed to each quartile of PM2.5 or PM10 concentrations or RH. Hazards regression was conducted to analyze the associations between exposure to each quartile of PM2.5 and PM10 concentrations and the risk of developing RA. The hazard ratios of RA were analyzed between participants exposed to annual average concentrations of PM2.5 and PM10. All the hazard ratios of RA were stratified by gender and adjusted for age and relative humidity (RH). A p-value < 0.05 was considered statistically significant. Results: Among 722,885 subjects, 9338 RA cases were observed. The analyses adjusted for age, gender, and humidity suggested an increased risk of developing RA in the exposure to PM2.5 in the last quartile (Q4) with the adjusted hazard ratio (aHR) was 1.053 (95%CI: 1.043 to 1.063). Conclusion: Our study suggests that exposure to PM2.5 is associated with an increased risk of RA. The finding has implications for policymaking to develop coping strategies to confront AAP as a risk factor for RA.

Content, Structure and Delivery Characteristics of Yoga Interventions for Managing Rheumatoid Arthritis: A Systematic Review Protocol

The global burden of rheumatoid arthritis among adults is rising. Yoga might be a potential solution for managing rheumatoid arthritis. This systematic review aims to synthesise the content, structure and delivery characteristics of effective yoga interventions for managing rheumatoid arthritis. The JBI methodology for systematic reviews of effectiveness and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines will be followed. PRISMA for systematic review protocols (PRISMA-P) was used to write the protocol. Randomised controlled trials assessing the effectiveness of yoga interventions for managing rheumatoid arthritis in adults will be included in this review. We aim to search the following databases to find published and unpublished studies: ABIM, AMED, AYUSH Research Portal, CAM-QUEST, CINAHL, CENTRAL, EMBASE, MEDLINE, PeDro, PsycInfo, SPORTDiscus, TRIP, Web of Science, DART-Europe-e-theses portal, EthOS, OpenGrey and ProQuest Dissertations and Theses. No date or language restrictions will be applied. A narrative synthesis will be conducted. Meta-regression will be conducted to explore the statistical evidence for which components (content, structure and delivery characteristics) of yoga interventions are effective.

The Geospatial Distribution of Myositis and Its Phenotypes in the United States and Associations With Roadways: Findings From a National Myositis Patient Registry

Background

Little is known about the spatial distribution of idiopathic inflammatory myopathies (IIM) in the United States (U.S.), or their geospatial associations.

Methods

We studied a national myositis patient registry, with cases diagnosed in the contiguous U.S. from 1985–2011 and comprised of dermatomyositis (DM, n = 484), polymyositis (PM, n = 358), and inclusion body myositis (IBM, n = 318) patients. To assess the association of myositis prevalence with distance from roads, we employed log-Gaussian Cox process models, offset with population density.

Results

The U.S. IIM case distribution demonstrated a higher concentration in the Northest. DM, IBM, and cases with lung disease were more common in the East, whereas PM cases were more common in the Southeast. One area in the West and one area in the South had a significant excess in cases of DM relative to PM and of cases with lung disease relative to those without lung disease, respectively. IIM cases tended to cluster, with between-points interactions more intense in the Northeast and less in the South. There was a trend of a higher prevalence of IIM and its major phenotypes among people living within 50 m of a roadway relative to living beyond 200 m. Demographic characteristics, rural-urban commuting area, and female percentage were significantly associated with the prevalence of IIM and with major phenotypes.

Conclusions

Using a large U.S. database to evaluate the spatial distribution of IIM and its phenotypes, this study suggests clustering in some regions of the U.S. and a possible association of proximity to roadways.

Association between long-term exposure to air pollution and immune-mediated diseases: a population-based cohort study

Objective

Environmental air pollution has been associated with disruption of the immune system at a molecular level. The primary aim of the present study was to describe the association between long-term exposure to air pollution and risk of developing immune-mediated conditions.

Methods

We conducted a retrospective observational study on a nationwide dataset of women and men. Diagnoses of various immune-mediated diseases (IMIDs) were retrieved. Data on the monitoring of particulate matter (PM)10 and PM2.5 concentrations were retrieved from the Italian Institute of Environmental Protection and Research. Generalised linear models were employed to determine the relationship between autoimmune diseases prevalence and PM.

Results

81 363 subjects were included in the study. We found a positive association between PM10 and the risk of autoimmune diseases (ρ+0.007, p 0.014). Every 10 µg/m³ increase in PM10 concentration was associated with an incremental 7% risk of having autoimmune disease. Exposure to PM10 above 30 µg/m3 and PM2.5 above 20 µg/m³ was associated with a 12% and 13% higher risk of autoimmune disease, respectively (adjusted OR (aOR) 1.12, 95% CI 1.05 to 1.20, and aOR 1.13, 95% CI 1.06 to 1.20). Exposure to PM10 was associated with an increased risk of rheumatoid arthritis; exposure to PM2.5 was associated with an increased risk of rheumatoid arthritis, connective tissue diseases (CTDs) and inflammatory bowel diseases (IBD).

Conclusion

Long-term exposure to air pollution was associated with higher risk of developing autoimmune diseases, in particular rheumatoid arthritis, CTDs and IBD. Chronic exposure to levels above the threshold for human protection was associated with a 10% higher risk of developing IMIDs.

Long-term PM2.5 exposure and various health outcomes: An umbrella review of systematic reviews and meta-analyses of observational studies

Adverse effects from exposure to particulate matter <2.5 μm in diameter (PM_2.5) on health-related outcomes have been found in a range of experimental and epidemiological studies. This study aimed to assess the significance, validity, and reliability of the relationship between long-term PM_2.5 exposure and various health outcomes. The Embase, PubMed, Web of Science, CNKI, WANFANG, VIP, and SinoMed databases and reference lists of the retrieved review articles were searched to obtain meta-analysis and systematic reviews focusing on PM_2.5-related outcomes as of August 31, 2021. Random-/fixed-effects models were applied to estimate summary effect size and 95% confidence intervals (CIs). The quality of included meta-analyses was evaluated based on the AMSTAR 2 tool. Small-study effect and excess significance bias studies were conducted to further assess the associations. Registered PROSPERO number: CRD42020200606. This included 24 articles involving 71 associations between PM_2.5 exposure and the health outcomes. The evidence for the positive association of 10 μg/m³ increments of long-term exposure to PM_2.5 and stroke incidence in Europe was convincing (effect size = 1.07, 95% CI: 1.05-1.10). There was evidence that was highly suggestive of a positive association between 10 μg/m³ increments of long-term exposure to PM_2.5 and the following health-related outcomes: mortality of lung cancer (effect size = 1.11, 95% CI: 1.08-1.13) and Alzheimer's disease (effect size = 4.79, 95% CI: 2.79-8.21). There was highly suggestive evidence that chronic obstructive pulmonary disease risk is positively associated with higher long-term PM_2.5 exposure versus lower long-term PM_2.5 exposure (effect size = 2.32, 95% CI: 1.88-2.86). In conclusion, the positive association of long-term exposure to PM_2.5 and stroke incidence in Europe was convincing. Given the validity of numerous associations of long-term exposure to PM_2.5 and health-related outcomes is subject to biases, more robust evidence is urgently needed.

Exploring the Differences in Molecular Mechanisms and Key Biomarkers Between Membranous Nephropathy and Lupus Nephritis Using Integrated Bioinformatics Analysis

Background: Both membranous nephropathy (MN) and lupus nephritis (LN) are autoimmune kidney disease. In recent years, with the deepening of research, some similarities have been found in the pathogenesis of these two diseases. However, the mechanism of their interrelationship is not clear. The purpose of this study was to investigate the differences in molecular mechanisms and key biomarkers between MN and LN. Method: The expression profiles of GSE99325, GSE99339, GSE104948 and GSE104954 were downloaded from GEO database, and the differentially expressed genes (DEGs) of MN and LN samples were obtained. We used Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for enrichment analysis of DEGs. A protein-protein interaction (PPI) network of DEGs was constructed using Metascape. We filtered DEGs with NetworkAnalyst. Finally, we used receiver operating characteristic (ROC) analysis to identify the most significant DEGs for MN and LN. Result: Compared with LN in the glomerulus, 14 DEGs were up-regulated and 77 DEGs were down-regulated in MN. Compared with LN in renal tubules, 21 DEGs were down-regulated, but no up-regulated genes were found in MN. According to the result of GO and KEGG enrichment, PPI network and Networkanalyst, we screened out six genes (IFI6, MX1, XAF1, HERC6, IFI44L, IFI44). Interestingly, among PLA2R, THSD7A and NELL1, which are the target antigens of podocyte in MN, the expression level of NELL1 in MN glomerulus is significantly higher than that of LN, while there is no significant difference in the expression level of PLA2R and THSD7A. Conclusion: Our study provides new insights into the pathogenesis of MN and LN by analyzing the differences in gene expression levels between MN and LN kidney samples, and is expected to be used to prepare an animal model of MN that is more similar to human.

Association between ambient air pollution and multiple sclerosis: a systemic review and meta-analysis

Recently, increasing attention has been paid to the effects of air pollutants on autoimmune diseases. The results of relationship between ambient air pollution and multiple sclerosis (MS) showed a variety of differences. Thus, the purpose of this study is to further clarify and quantify the relationship between ambient air pollutants and MS through meta-analysis. Through electronic literature search, literature related to our research topic was collected in Cochrane Library, Embase, and PubMed till August 18, 2020, according to certain criteria. Pooled risk estimate and 95% confidence intervals (95%CI) were calculated by random-effect model analysis. After removing copies, browsing titles and abstracts, and reading full text, 6 studies were finally included. The results showed that only particulate matter (PM) with aerodynamic diameter ≤ 10 (PM₁₀) was related to MS (pooled HR = 1.058, 95% CI = 1.050-1.066), and no correlation was found between PM with aerodynamic diameter < 2.5 (PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), benzene (C₆H₆), major road < 50 m, and MS. There was no publication bias, and the heterogeneity analysis results were stable. PM₁₀ is correlated with the disease MS, while other pollution is not connected with MS. Therefore, it is important for MS patients to take personal protection against particulate pollution and avoid exposure to higher levels of PM.

Airborne pollutants as potential triggers of systemic autoimmune rheumatic diseases: a narrative review

The pathogenesis of systemic autoimmune rheumatic diseases (SARDs) is complex and remains insufficiently understood. It is commonly accepted that both intrinsic and extrinsic environmental factors interact to induce a self-reactive immune response. Case reports and observational studies have revealed an association between SARDs and specific airborne environmental factors, but the heterogeneity of the published studies hampers clear conclusions. The aim of this review is to provide an overview of the available epidemiological evidence on the relationship between airborne pollutants and SARDs. We performed a narrative review using the PubMed database. Observational studies have shown significant associations between airborne pollutants and SARDs. Cigarette smoking is strongly associated with the development of rheumatoid arthritis (RA) while the association between cigarette smoke and the development of other SARDs remains controversial. For decades, silica exposure has been linked to systemic sclerosis (SSc), RA and systemic lupus erythematosus (SLE). There is also strong evidence for a link between solvents and SSc. Recent observations even suggest that ambient air pollution is associated with the development of SARDs. Some studies have shown associations between asbestos, organic dust, metals and pesticides and SARDs, but more studies are needed to confirm these findings. Increasing evidence has linked airborne pollutants to SARDs. Although more studies are needed to understand the potential mechanisms by which these environmental agents contribute to disease pathogenesis, awareness of the link between environmental agents and SARDs is important to recognize and prevent work-related and environmentally induced diseases.

Impact of Posttranslational Modification in Pathogenesis of Rheumatoid Arthritis: Focusing on Citrullination, Carbamylation, and Acetylation

Rheumatoid arthritis (RA) is caused by prolonged periodic interactions between genetic, environmental, and immunologic factors. Posttranslational modifications (PTMs) such as citrullination, carbamylation, and acetylation are correlated with the pathogenesis of RA. PTM and cell death mechanisms such as apoptosis, autophagy, NETosis, leukotoxic hypercitrullination (LTH), and necrosis are related to each other and induce autoantigenicity. Certain microbial infections, such as those caused by Porphyromonasgingivalis, Aggregatibacter actinomycetemcomitans, and Prevotella copri, can induce autoantigens in RA. Anti-modified protein antibodies (AMPA) containing anti-citrullinated protein/peptide antibodies (ACPAs), anti-carbamylated protein (anti-CarP) antibodies, and anti-acetylated protein antibodies (AAPAs) play a role in pathogenesis as well as in prediction, diagnosis, and prognosis. Interestingly, smoking is correlated with both PTMs and AMPAs in the development of RA. However, there is lack of evidence that smoking induces the generation of AMPAs.

Potential Short-Term Air Pollution Effects on Rheumatoid Arthritis Activity in Metropolitan Areas in the North of Italy: A Cross-Sectional Study

Rheumatoid arthritis (RA) flare is related to increased joint damage, disability, and healthcare use. The impact of short-term air pollution exposure on RA disease activity is still a matter of debate. In this cross-sectional study, we investigated whether short-term exposure to particulate matter (PM)₁₀, PM_2.5, nitrogen dioxide (NO₂), and ozone (O₃) affected RA disease activity (DAS28 and SDAI) in 422 consecutive RA residents in Lombardy, North of Italy. Air pollutant concentrations, estimated by Regional Environmental Protection Agency (Lombardy—Italy) at the municipality level, were used to assign short-term exposure from the day of enrolment, back to seven days. Some significant negative associations emerged between RA disease activity, PM₁₀, and NO₂, whereas some positive associations were observed for O₃. Patients were also stratified according to their ongoing Disease-Modifying anti-Rheumatic Drugs (DMARDs) treatment: no DMARDs (n = 25), conventional synthetic DMARDs (n = 108), and biological or targeted synthetic DMARDs (n = 289). Therapy interaction seemed partially able to influence the relationship between short-term air pollution exposure and RA disease activity (PM_2.5 levels and DAS28 at the day of the visit-O₃ levels and disease activity scores for the seven days before the evaluation). According to our results, the impact of short-term air pollution exposure (seven days) minimally impacts disease activity. Moreover, our study suggests therapy could alter the response to environmental factors. Further evidence is needed to elucidate determinants of RA flare and its management.

Prospective correlational time-series analysis of the influence of weather and air pollution on joint pain in chronic rheumatic diseases

OBJECTIVES

The primary objective was to evaluate the association between weather variables and joint pain in patients with chronic rheumatic diseases (CRD: rheumatoid arthritis (RA), osteoarthritis (OA), and spondyloarthritis (SpA)). A secondary objective was to study the impact of air pollution indicators on CRD pain.

METHOD

The study is prospective, correlational, with time-series analysis. Patients with CRD, living in a predefined catchment area, filled their level of pain daily using a 0-10 numerical scale (NS), for 1 year. Weather (temperature, relative humidity (H), atmospheric pressure (P)) and air pollution indicators (particulate matters (PM₁₀, PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃)) were recorded daily using monitoring systems positioned in the same area. Association between pain and weather and air pollution indicators was studied using Pearson's correlation. Time-series analysis methodology was applied to determine the temporal relationship between pain and indicators.

RESULTS

The study included 94 patients, 82% reported they were weather-sensitive. Pain variation was similar across diseases over a year. Pain was associated negatively with temperature, H, and O_3, and positively with P and NO₂. However, the strength of correlation was moderate; temperature explained 22% of pain variance. A drop of 10°C in temperature corresponded to an increase of 0.5 points in pain NS. Also, there was a significant interaction among environmental factors. In time-series analysis, temperature and NO₂ remained independently associated with pain.

CONCLUSIONS

The perception of joint pain in patients with CRD was correlated with weather and air pollution. The strength of association was moderate and independent of underlying disease. Key Points •Weather variation was moderately correlated with joint pain in chronic rheumatic diseases, with an inverse association with temperature, humidity, and O₃. • Air pollution indicators, mainly nitrogen dioxide and ozone, were correlated with joint pain; particulate matters were also correlated but to a lesser extent. • The influence of these environmental factors was independent of the type of rheumatic disease, thus raising the hypothesis of their impact on pain perception mechanisms.

Immunomodulatory Effects of Mesenchymal Stem Cells and Mesenchymal Stem Cell-Derived Extracellular Vesicles in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints and other organs for which there is currently no effective treatment. Mesenchymal stem cells (MSCs) have therapeutic potential due to their immunomodulatory and differentiation effects. While extensive experimental studies and clinical trials have demonstrated the effects of MSCs in various diseases, MSCs have been found to cause abnormal differentiation and tumor formation. Therefore, extracellular vesicles derived from MSCs (MSC-EVs) are more effective, less toxic, and more stable than the parental cells. MSC-EVs transfer various nucleic acids, proteins, and lipids from parent cells to recipient cells, and thus participate in chronic inflammatory and immune processes. In this review, we summarize the properties and biological functions of MSCs and MSC-EVs in RA. Improvement in our understanding of the mechanisms underlying MSC and MSC-EVs in RA provides an insight into potential biomarkers and therapeutic strategies for RA.

Long-term exposure to a mixture of industrial SO2, NO2, and PM2.5 and anti-citrullinated protein antibody positivity

BACKGROUND

Studies of associations between industrial air emissions and rheumatic diseases, or diseases-related serological biomarkers, are few. Moreover, previous evaluations typically studied individual (not mixed) emissions. We investigated associations between individual and combined exposures to industrial sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and fine particles matter (PM_2.5) on anti-citrullinated protein antibodies (ACPA), a characteristic biomarker for rheumatoid arthritis (RA).

METHODS

Serum ACPA was determined for 7600 randomly selected CARTaGENE general population subjects in Quebec, Canada. Industrial SO₂, NO₂, and PM_2.5 concentrations, estimated by the California Puff (CALPUFF) atmospheric dispersion model, were assigned based on residential postal codes at the time of sera collection. Single-exposure logistic regressions were performed for ACPA positivity defined by 20 U/ml, 40 U/ml, and 60 U/ml thresholds, adjusting for age, sex, French Canadian origin, smoking, and family income. Associations between regional overall PM_2.5 exposure and ACPA positivity were also investigated. The associations between the combined three industrial exposures and the ACPA positivity were assessed by weighted quantile sum (WQS) regressions.

RESULTS

Significant associations between individual industrial exposures and ACPA positivity defined by the 20 U/ml threshold were seen with single-exposure logistic regression models, for industrial emissions of PM_2.5 (odds ratio, OR = 1.19, 95% confidence intervals, CI: 1.04-1.36) and SO₂ (OR = 1.03, 95% CI: 1.00-1.06), without clear associations for NO₂ (OR = 1.01, 95% CI: 0.86-1.17). Similar findings were seen for the 40 U/ml threshold, although at 60 U/ml, the results were very imprecise. The WQS model demonstrated a positive relationship between combined industrial exposures and ACPA positivity (OR = 1.36, 95% CI: 1.10-1.69 at 20 U/ml) and suggested that industrial PM_2.5 may have a closer association with ACPA positivity than the other exposures. Again, similar findings were seen with the 40 U/ml threshold, though 60 U/ml results were imprecise. No clear association between ACPA and regional overall PM_2.5 exposure was seen.

CONCLUSIONS

We noted positive associations between ACPA and industrial emissions of PM_2.5 and SO₂. Industrial PM_2.5 exposure may play a particularly important role in this regard.