Prenatal, infantile, and childhood tobacco exposure and risk of pediatric psoriasis in the Danish National Birth Cohort offspring

Effects and mechanisms of polycyclic aromatic hydrocarbons in inflammatory skin diseases

Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons characterized by the presence of multiple benzene rings. They are ubiquitously found in the natural environment, especially in environmental pollutants, including atmospheric particulate matter, cigarette smoke, barbecue smoke, among others. PAHs can influence human health through several mechanisms, including the aryl hydrocarbon receptor (AhR) pathway, oxidative stress pathway, and epigenetic pathway. In recent years, the impact of PAHs on inflammatory skin diseases has garnered significant attention, yet many of their underlying mechanisms remain poorly understood. We conducted a comprehensive review of articles focusing on the link between PAHs and several inflammatory skin diseases, including psoriasis, atopic dermatitis, lupus erythematosus, and acne. This review summarizes the effects and mechanisms of PAHs in these diseases and discusses the prospects and potential therapeutic implications of PAHs for inflammatory skin diseases.

Multiple environmental antigens may trigger autoimmunity in psoriasis through T-cell receptor polyspecificity

Introduction

Psoriasis is a T-cell mediated autoimmune skin disease. HLA-C*06:02 is the main psoriasis-specific risk gene. Using a Vα3S1/Vβ13S1 T-cell receptor (TCR) from a lesional psoriatic CD8+ T-cell clone we had discovered that, as an underlying pathomechanism, HLA-C*06:02 mediates an autoimmune response against melanocytes in psoriasis, and we had identified an epitope from ADAMTS-like protein 5 (ADAMTSL5) as a melanocyte autoantigen. The conditions activating the psoriatic autoimmune response in genetically predisposed individuals throughout life remain incompletely understood. Here, we aimed to identify environmental antigens that might trigger autoimmunity in psoriasis because of TCR polyspecificity.

Methods

We screened databases with the peptide recognition motif of the Vα3S1/Vβ13S1 TCR for environmental proteins containing peptides activating this TCR. We investigated the immunogenicity of these peptides for psoriasis patients and healthy controls by lymphocyte stimulation experiments and peptide-loaded HLA-C*06:02 tetramers.

Results

We identified peptides from wheat, Saccharomyces cerevisiae, microbiota, tobacco, and pathogens that activated both the Vα3S1/Vβ13S1 TCR and CD8+ T cells from psoriasis patients. Using fluorescent HLA-C*06:02 tetramers loaded with ADAMTSL5 or wheat peptides, we find that the same CD8+ T cells may recognize both autoantigen and environmental antigens. A wheat-free diet could alleviate psoriasis in several patients.

Discussion

Our results show that due to TCR polyspecificity, several environmental antigens corresponding to previously suspected psoriasis risk conditions converge in the reactivity of a pathogenic psoriatic TCR and might thus be able to stimulate the psoriatic autoimmune response against melanocytes. Avoiding the corresponding environmental risk factors could contribute to the management of psoriasis.

Prenatal and adult exposure to smoking and incidence of type 1 diabetes in children and adults-a nationwide cohort study with a family-based design

Background

Prenatal exposure to smoking is linked to a reduced risk of type 1 diabetes in children. We wanted to find out if the risk of adult-onset type 1 diabetes is reduced in individuals who are exposed to smoking prenatally or during adulthood.

Methods

We linked Swedish, nationwide registers and prospectively analyzed incidence of type 1 diabetes in relation to maternal smoking during pregnancy and adult smoking. Everyone was followed until age 30 or year 2019. We employed cohort and sibling design and used adjusted Cox regression and conditional logistic regression.

Findings

For analyses of maternal smoking there were 3,170,386 individuals (18,745 cases of type 1 diabetes) and for adult smoking 1,608,291 individuals (1274 cases). Prenatal exposure to smoking was associated with lower incidence of type 1 diabetes during childhood and young adulthood (age 20-24, Hazard ratio (HR) 0.76, 95% Confidence interval 0.67-0.87), but not at higher ages. The HR associated with adult smoking was estimated at 1.14 (CI 1.00-1.31) overall and 1.34 (CI 1.03-1.75) in those with family history of diabetes. In sibling analyses, the odds ratio (OR) of type 1 diabetes in relation to prenatal exposure was 0.71 (CI 0.62-0.81) in children and 1.06 (CI 0.75-1.51) in adults (age 19-30), while adult smoking conferred an OR of 1.59 (CI 1.08-2.35).

Interpretation

These findings indicate that a reduced risk conferred by tobacco exposure is limited to the prenatal period and type 1 diabetes developing during childhood. Adult smoking may be a risk factor for adult-onset type 1 diabetes, especially in people with family history of diabetes.

Funding

Swedish Research Councils, Swedish Diabetes and Novo Nordisk Foundations, China Scholarship Council.

Depression, a major comorbidity of psoriatic disease, is caused by metabolic inflammation

Psoriatic disease is a chronic, systemic immune-mediated inflammatory disorder comprising three major domains, skin, vascular and bone/joint inflammation. It is known for a long time that psoriatic disease is associated with a number of conditions such as hypertension, dyslipidemia, diabetes (metabolic syndrome) and depression. Up to one out of five people with psoriasis show concomitant depression. In the past, this was attributed to psychological stress of suffering from a chronic condition that is often visible and itchy, leading to stigmatization and adding to a significant burden of disease. Recent data provide evidence that depression associated with psoriatic disease is linked to the specific inflammatory pattern with IL-23, IL-17 family cytokines, TNF, IL-6 and IL-8 causing neuroinflammation and subsequently depression or depressive behaviour and/or anxiety. Psoriatic disease shows a distinct pattern of immune cells (e.g. dendritic cells, Th17 cells, neutrophils), mediators (e.g. IL-17A/F, IL-23, TNF) and tissue-related factors in all major domains that is different from other inflammatory dermatoses. There is a striking similarity between the inflammatory pattern in psoriatic disease and neuroinflammation that leads to depression. A number of risk factors have been identified in psoriatic disease, the most important of which are obesity and tobacco smoking. Obesity is known as a major risk factor for depression and anxiety due to its inflammatory signature. Apart from psychotherapy and anti-depressive medication, targeted treatments for psoriasis, including TNF, IL-17 and IL-23 inhibitors, can improve depression/depressive symptoms. The review summarizes the current knowledge about depression as a comorbidity in psoriatic disease.

Smoking is an independent but not a causal risk factor for moderate to severe psoriasis: A Mendelian randomization study of 105,912 individuals

Background

Smoking is strongly associated with higher risk of psoriasis in several observational studies; however, whether this association is causal or can be explained by confounding or reverse causation is not fully understood. Randomized controlled trials are the gold standard when examining causality; however, when this method is not feasible, the Mendelian randomization design is an alternative. Herein genetic variants can be used as robust proxies for modifiable exposures and thereby avoiding confounding and reverse causation.In this study, we hypothesized that smoking is an independent and causal risk factor for psoriasis and tested this using a Mendelian randomization design.

Methods

We used data from the Copenhagen General Population Study including 105,912 individuals with full information on lifestyle factors, biochemistry, and genotype data. In total, 1,240 cases of moderate to severe psoriasis were included to investigate the association between smoking and psoriasis. To assess causality of the association, we used the genetic variant CHRNA3 rs1051730, where the T-allele is strongly associated with high lifelong cumulative smoking, as a proxy for smoking.

Results

In observational analyses, the multivariable adjusted hazard ratio of developing moderate to severe psoriasis was 1.64 (95% confidence interval: 1.35-2.00) in ever smokers with ≤ 20 pack-years and 2.23 (1.82-2.73) in ever smokers with > 20 pack-years compared to never smokers. In genetic analyses, the odds ratio of developing moderate to severe psoriasis was 1.05 (0.95-1.16) per CHRNA3 rs10511730 T-allele in ever smokers.

Conclusion

Smoking was an independent risk factor for moderate to severe psoriasis in observational analyses. However, using a genetic variant as a robust proxy for smoking, we did not find this association to be causal.

Prevalence of Tobacco Smoking and Its Association With Disease Severity Among Patients With Psoriasis in China: A Cross-Sectional Study

Introduction

Tobacco smoking is associated with the onset and severity of psoriasis, and understanding the prevalence of tobacco smoking among patients with psoriasis is critical due to its high physical and mental influence and heavy disease burden. However, evidence on the association between tobacco smoking and psoriasis severity is still limited in China.

Objectives

The objective of this study was to examine the prevalence of tobacco smoking and explore the association between tobacco smoking and diseases severity among patients with psoriasis.

Methods

A total of 4,529 patients with psoriasis in 200 selected hospitals were recruited in China between January 2020 and September 2021. Detailed information covering demographic feature, tobacco smoking, and psoriasis history were collected through an electronic questionnaire, and clinical data were extracted from the health information system (HIS). SAS 9.4 was used for data analysis, and a p-value of <0.05 was considered statistically significant.

Results

The prevalence of tobacco smoking was 30.8%, with 24.6% for current smoking. The average Psoriasis Area and Severity Index (PASI) score for patients with psoriasis was 9.4, with male patients having a higher PASI score than female patients. The odds ratio (OR) of former tobacco smoking prevalence was 1.5 [95% confidence interval (CI): (1.0-2.3)] for PASI score (3.0-7.0), 2.2 for PASI score (7.1-13.0), and 4.2 for PASI score >13, when compared with patients with PASI score < 3.0. Similarly, the OR of current tobacco smoking prevalence was 1.8 [95% CI: (1.5-2.2)] for PASI score (3.0-7.0), 1.9 for PASI score (7.1-13.0), and 3.1 for PASI score >13, when compared with patients with PASI score <3.0. The Spearman correlation analysis indicated that both tobacco smoking intensity and smoking duration were positively correlated with psoriasis severity (p < 0.05).

Conclusion

The prevalence of tobacco smoking was high, especially among male patients with psoriasis and those with senior high education. Tobacco smoking was positively associated with psoriasis severity; moreover, both smoking intensity and smoking duration were positively correlated with the severity of psoriasis in a dose-dependent fashion.

Link between childhood tobacco exposure and childhood psoriasis: A case-control study

INTRODUCTION

Childhood psoriasis is not uncommon, and its prevalence is estimated to be 128 per 100,000 children. There are sparse data regarding intrauterine and environmental tobacco smoke exposure and the development of psoriasis in childhood. In this study, we aimed to investigate these parameters in the Turkish pediatric population.

MATERIALS AND METHODS

We included 130 children with psoriasis and 390 children as controls. For each risk factor, odds ratios of psoriasis as an estimate of relative risks and corresponding 95% confidence interval were calculated. Univariate conditional logistic regression analysis was used to determining the crude odds ratio. Subsequently, to evaluate the effects of potential confounding factors, multivariate conditional logistic regression analysis was used.

RESULTS

Childhood psoriasis (CP) was found to be associated with environmental tobacco smoke exposure irrespective of intrauterine smoking exposure, family history of psoriasis, and obesity (OR: 2.23, 95% CI = 1.39-3.58), whereas multiple logistic regression analysis did not show a relationship between CP and intrauterine tobacco exposure (OR: 1.61, 95% CI = 0.75-3.43).

CONCLUSIONS

Environmental tobacco smoke exposure at home denotes an important preventable risk factor for developing CP. Further studies are needed to elucidate the relationship between CP and environmental tobacco exposure investigating a large cohort of CP patients who have been diagnosed by expert dermatologists.

Off-Label Treatments for Pediatric Psoriasis: Lessons for the Clinic

Psoriasis is a chronic inflammatory skin disease that affects up to 1.2% of children and adolescents. The treatment options for childhood psoriasis are often based on the same principles as in adults. However, most data on safety and efficacy derive from adult studies, and only a few of the frequently used treatments have achieved approval for use in children. The aim of this study was to review the current literature on off-label treatments for psoriasis in children and adolescents. We searched PubMed and identified 50 studies on off-label treatments. Of these, 23 studies were clinical trials (four randomized). There are only a small number of available studies on off-label treatments for children and adolescents with psoriasis, and many of these are retrospective reviews with few participants. Despite the current lack of studies, we still recommend the use of unapproved treatments since we have clinical experience with treatments such as topical corticosteroids, vitamin D analogs, and methotrexate that have shown promising effects. Regular clinical trials are needed to investigate the safety and efficacy of unapproved treatments. Due to The Pediatric Investigation Plans issued by The European Union, new drugs developed by pharmaceutical companies are required to undergo clinical trials in a pediatric population to get their application for marketing authorization processed. This will hopefully lead to much more data on the efficacy and safety of the new treatments, including treatments for children and adolescents with psoriasis.

Infantile infection and antibiotic exposure in association with pediatric psoriasis development: A nationwide nested case-control study

BACKGROUND

Microbiol dysbiosis and antibiotic exposure have been implicated in the pathogenesis of pediatric inflammatory diseases.

OBJECTIVES

To investigate the impacts of infantile infection and antibiotic exposure on pediatric psoriasis development.

METHODS

This is a nationwide nested case-control study. From the National Health Insurance Research Database of Taiwan, a total of 1527 patients with pediatric psoriasis were identified and matched with 15,270 reference individuals without psoriasis, for the period of 2000 to 2017. Demographic characteristics and comorbidities were compared. Conditional stepwise logistic regression analysis was conducted to examine the associations.

RESULTS

The mean ages were 9.9 ± 3.7 years in both groups. Atopic dermatitis (adjusted odds ratio [aOR], 2.07; 95% confidence interval [CI], 1.84-2.32) and family history of psoriasis, especially of the mother (aOR, 9.86; 95% CI, 6.89-14.10) or other first-degree relatives (aOR, 5.49; 95% CI, 3.91-7.70), were independently associated with pediatric psoriasis on multivariate analyses. Skin viral and bacterial infections (aOR, 1.35; 95% CI, 1.13-1.62) and fungal infections (aOR, 1.71; 95% CI, 1.44-2.04) in the first 2 years of life were significantly associated with pediatric psoriasis. Systemic antibiotic exposure was not. These results were consistent at different time periods across sensitivity analyses.

LIMITATION

Information about diet and lifestyle was not available.

CONCLUSION

Skin infections at an early age were associated with pediatric psoriasis development.

Impact of smoking on psoriasis risk and treatment efficacy: a meta-analysis

Objective

Psoriasis is an immune-mediated chronic inflammatory disease with skin and joint manifestations. Smoking is considered an unfavorable lifestyle factor for psoriasis. We aimed to explore the association between smoking, disease risk, and treatment efficacy in relation to psoriasis.

Methods

We searched the Cochrane Library, Embase, and PubMed databases for studies examining the relationship between smoking and psoriasis, up to 12 April 2020. We then conducted a meta-analysis using a fixed-effects model to obtain odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Ever, current, and former smokers all had higher risks of developing psoriasis than non-smokers (pooled ORs (95% CIs): 1.60 (1.51–1.69), 1.63 (1.48–1.80), and 1.36 (1.13–1.64), respectively). Ever smokers were less likely to show disease improvement at 6 months following treatment with biologic agents than non-smokers (pooled OR (95% CI): 0.80 (0.67–0.95)).

Conclusions

Smoking increases psoriasis risk and negatively impacts the benefits of biologic agents. However, the number of reports is limited and more studies are needed to confirm the effects of smoking and smoking cessation on therapeutic response in patients with psoriasis. Education to encourage a healthy lifestyle remains a valuable approach in clinical practice.

Psoriasis Among Adolescents in Kuwait and the Role of Siblings, Breastfeeding, and Household Cat and Secondhand Smoke Exposure: A Cross-Sectional Study

INTRODUCTION

Globally, the epidemiology of psoriasis is poorly understood, and most countries lack essential epidemiologic data regarding disease burden and its determinants. This study sought to estimate the prevalence of psoriasis among adolescents in Kuwait and assess its association with different risk factors, including obesity, sibship size, breastfeeding, and exposure to household secondhand smoke (SHS) and pets.

METHODS

Schoolchildren aged 11-14 years (n = 3864) were enrolled in a cross-sectional study. Lifetime and current (past 12 months) prevalence of psoriasis were ascertained according to ever having a history of doctor-diagnosis plus current active lesion(s) and/or current use of treatment of psoriasis. Associations were assessed using Poisson regression with robust variance estimation, and adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated.

RESULTS

The lifetime and current prevalence of psoriasis were estimated to be 3.6% (136/3806) and 1.1% (42/3806), respectively. Commonly reported anatomical sites affected by psoriasis included scalp (47.6%) and the extensor surface of the knees (50%) and elbows (38.1%). Household SHS exposure was associated with increased lifetime psoriasis (aPR = 1.41, 95% CI 1.07-1.98), and showed a trend for association with current psoriasis (1.77, 0.89-3.53). Similarly, cat-keeping during infancy was associated with lifetime psoriasis (1.96, 1.14-3.37), and demonstrated a trend for association with current psoriasis (1.49, 0.52-1.98). In contrast, breastfeeding was associated with a decreased lifetime psoriasis (0.62, 0.44-0.89), but was not associated with current psoriasis. Trend analyses showed that the prevalence of lifetime and current psoriasis increased with increasing numbers of total, older, and younger siblings.

CONCLUSIONS

Psoriasis affects a considerable proportion of schoolchildren in Kuwait. Interestingly, psoriasis prevalence was related to risk factors also found in allergic diseases, such as exposure to SHS, cat-keeping in infancy, breastfeeding, and sibship size, possibly suggesting a role of immune dysregulation.