“Inflammatory skin march”: IL-1–mediated skin inflammation, atopic dermatitis, and psoriasis to cardiovascular events

New treatment of pyoderma gangrenosum and hidradenitis suppurativa: A review

Pyoderma gangrenosum (PG) and hidradenitis suppurativa (HS) are stubborn inflammatory skin diseases categorized as neutrophilic hypodermal dermatoses. These conditions exhibit connections with other autoinflammatory disorders driven by immune responses. Their pathogenesis is complex, rooted in significant imbalances in both innate and adaptive immune systems, particularly featuring elevated levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-8, IL-17, and IL-23. Studies involving skin tissue pathology and serology have indicated that targeting specific cytokines can bring therapeutic benefits. Indeed, many patients in clinical settings have responded positively to such interventions. Yet, given the diverse cytokines in play, focusing on a single one with antibody therapy might not always be effective. When resistance to biologics emerges, a combined approach targeting multiple overactive cytokines with immunosuppressants, for example cyclosporine and Janus kinase inhibitors, could be an option. In the current review, we explore recent therapeutic developments for PG and HS.

Increased Mortality Risk at Septic Condition in Inflammatory Skin Disorders and the Effect of High-Fat Diet Consumption

In recent years, attention has increasingly focused on various infectious diseases. Although some fatalities are directly attributed to the causative virus, many result from complications and reactive inflammation. Patients with comorbidities are at a higher risk of mortality. Refractory skin conditions such as atopic dermatitis, psoriasis, and epidermolysis bullosa, known for an elevated risk of sepsis, partly owe this to compromised surface barrier function. However, the detailed mechanisms underlying this phenomenon remain elusive. Conversely, although the detrimental effects of a high-fat diet on health, including the onset of metabolic syndrome, are widely recognized, the association between diet and susceptibility to sepsis has not been extensively explored. In this study, we examined the potential causes and pathogenesis of increased sepsis susceptibility in inflammatory skin diseases using a mouse dermatitis model: keratin 14-driven caspase-1 is overexpressed (KCASP1Tg) in mice on a high-fat diet. Our findings reveal that heightened mortality in the dermatitis mouse model is caused by the inflamed immune system due to the chronic inflammatory state of the local skin, and administration of LPS causes a rapid increase in inflammatory cytokine levels in the spleen. Intake of a high-fat diet exacerbates these cytokine levels. Interestingly, we also observed a reduced expression of Toll-like receptor 4 (TLR4) in monocytes from KCASP1Tg mice, potentially predisposing these animals to heightened infection risks and associated complications. Histological analysis showed a clear decrease in T and B cells in the spleen of KCASP1Tg mice fed a high-fat diet. Thickening of the alveolar wall, inflammatory cell infiltration, and alveolar hemorrhage were more prominent in the lungs of KCASP1Tg and KCASP1Tg with fat mice. We postulate that the chronic, non-infectious inflammation induces a negative feedback loop within the inflammatory cascade, and the suppressed expression of TLR4 renders the mice more susceptible to infections. Therefore, it is imperative for individuals with chronic skin inflammation to closely monitor disease progression upon infection and seek timely and appropriate treatment. Additionally, chronic inflammation of adipose tissue, induced by high-fat food intake, combined with dermatitis inflammation, may exacerbate infections, necessitating a review of dietary habits.

Risk of type 2 diabetes mellitus in adult patients with atopic dermatitis

AIMS

This study aimed to investigate the subsequent risk of type 2 diabetes mellitus (T2D) in adults newly diagnosed with atopic dermatitis (AD).

METHODS

This propensity score-matching cohort study used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) 2.0 database in South Korea from 2002 to 2015. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox proportional hazards model, for the new onset of T2D (ICD-10 code, E11) in AD patients compared to the matched controls. Subgroup and sensitivity analyses were also conducted.

RESULTS

Each of the 36,692 individuals in the AD group and matched control group was included in the analysis. The risk of T2D in the AD group was significantly higher than that of the matched controls in the adjusted model (adjusted HR 1.44; 95% CI 1.27-1.63, P <.001). The results of subgroup analysis by sex, age, and body mass index were consistent with the results of the primary analysis. Sensitivity analyses using different T2D and/or AD definitions also showed consistent results.

CONCLUSIONS

The significant risk of subsequent T2D in adult AD patients suggested the necessity for efforts to prevent T2D in AD patients.

Atopic Dermatitis and the Risk of Myocardial Infarction and All-Cause Mortality: A Nationwide Population-Based Cohort Study

PURPOSE

Atopic dermatitis (AD) is a chronic inflammatory skin disorder associated with various comorbidities. However, inconsistent results on the risk of myocardial infarction (MI) and mortality have been reported in patients with AD. This study was aimed to evaluate the risk of MI and all-cause mortality in patients with AD.

METHODS

This nationwide population-based retrospective cohort study enrolled 56,205 adults ≥ 20 years of age with AD and 3,825,609 controls without AD from the Korean National Health Service (NHIS) database from 2009 to 2016.

RESULTS

The risk of MI (adjusted hazard ratio [aHR], 1.111, 95% confidence interval [CI], 1.050-1.176) was increased in patients with AD. By AD severity, patients with moderate-to-severe AD had a higher risk of MI (aHR, 1.163, 95% CI, 1.080-1.251) than individuals without AD. The risk of all-cause mortality was only increased for patients with moderate-to-severe AD (aHR, 1.096, 95% CI, 1.040-1.155) compared to individuals without AD. In subgroup analysis, an increased risk of MI was observed in female, non-obese, non-smoking, non-diabetic, and non-dyslipidemic patients with moderate-to-severe AD compared to individuals without AD. An increased risk of all-cause mortality was observed in patients with moderate-to-severe AD compared to non-AD controls among individuals ≥60 years of age and non-smokers.

CONCLUSIONS

The risk of MI and all-cause death was increased in patients with moderate-to-severe AD. Even without well-known risk factors for MI and mortality, patients with AD require the proper management and screening for comorbidities to prevent MI and decrease all-cause mortality.

Disease modification in inflammatory skin disorders: opportunities and challenges

Progress in understanding of the mechanisms underlying chronic inflammatory skin disorders, such as atopic dermatitis and psoriasis vulgaris, has led to new treatment options with the primary goal of alleviating symptoms. In addition, this knowledge has the potential to inform on new strategies aimed at inducing deep and therapy-free remission, that is, disease modification, potentially impacting on associated comorbidities. However, to reach this goal, key areas require further exploration, including the definitions of disease modification and disease activity index, further understanding of disease mechanisms and systemic spillover effects, potential windows of opportunity, biomarkers for patient stratification and successful intervention, as well as appropriate study design. This Perspective article assesses the opportunities and challenges in the discovery and development of disease-modifying therapies for chronic inflammatory skin disorders.

Inflammatory Skin Disease Causes Anxiety Symptoms Leading to an Irreversible Course

Intense itching significantly reduces the quality of life, and atopic dermatitis is associated with psychiatric conditions, such as anxiety and depression. Psoriasis, another inflammatory skin disease, is often complicated by psychiatric symptoms, including depression; however, the pathogenesis of these mediating factors is poorly understood. This study used a spontaneous dermatitis mouse model (KCASP1Tg) and evaluated the psychiatric symptoms. We also used Janus kinase (JAK) inhibitors to manage the behaviors. Gene expression analysis and RT-PCR of the cerebral cortex of KCASP1Tg and wild-type (WT) mice were performed to examine differences in mRNA expression. KCASP1Tg mice had lower activity, higher anxiety-like behavior, and abnormal behavior. The mRNA expression of S100a8 and Lipocalin 2 (Lcn2) in the brain regions was higher in KCASP1Tg mice. Furthermore, IL-1β stimulation increased Lcn2 mRNA expression in astrocyte cultures. KCASP1Tg mice had predominantly elevated plasma Lcn2 compared to WT mice, which improved with JAK inhibition, but behavioral abnormalities in KCASP1Tg mice did not improve, despite JAK inhibition. In summary, our data revealed that Lcn2 is closely associated with anxiety symptoms, but the anxiety and depression symptoms caused by chronic skin inflammation may be irreversible. This study demonstrated that active control of skin inflammation is essential for preventing anxiety.

The Interplay of Type 1, Type 2, and Type 3 Lymphocytes and Cytokines in Atopic Dermatitis

Atopic dermatitis (AD) is classified as a type 2 disease owing to the majority of type 2 lymphocytes that constitute the skin-infiltrating leukocytes. However, all of the type 1-3 lymphocytes intermingle in inflamed skin lesions. Here, using an AD mouse model where caspase-1 was specifically amplified under keratin-14 induction, we analyzed the sequential changes in type 1-3 inflammatory cytokines in lymphocytes purified from the cervical lymph nodes. Cells were cultured and stained for CD4, CD8, and γδTCR, followed by intracellular cytokines. Cytokine production in innate lymphocyte cells (ILCs) and the protein expression of type 2 cytokine IL-17E (IL-25) were investigated. We observed that, as inflammation progresses, the cytokine-producing T cells increased and abundant IL-13 but low levels of IL-4 are produced in CD4-positive T cells and ILCs. TNF-α and IFN-γ levels increased continuously. The total number of T cells and ILCs peaked at 4 months and decreased in the chronic phase. In addition, IL-25 may be simultaneously produced by IL-17F-producing cells. IL-25-producing cells increased in a time-dependent manner during the chronic phase and may work specifically for the prolongation of type 2 inflammation. Altogether, these findings suggest that inhibition of IL-25 may be a potential target in the treatment of inflammation.

Treatment in Patients with Psoriatic Disease and Rheumatoid Arthritis: Seven Case Reports

The incidence of psoriasis, an intractable long-lasting inflammatory skin disease, is increasing and has many complications and comorbidities. Approximately 14% of patients have psoriatic arthritis (PsA). Rheumatoid arthritis (RA) is not a rare disease worldwide, and some patients may have both PsA and RA. In the present study, we encountered seven patients with concurrent diagnoses of RA and psoriatic disease and reported the details of clinical data, treatment efficacy, and X-ray findings. The diagnosis may require not only classification criteria but also a comprehensive judgment in collaboration with rheumatology over time. In addition to methotrexate as an anchor drug, anti-tumor necrosis factor-α agents are the first choice of biological agents for treatment, and interleukin (IL)-17 inhibitors may be effective, as IL-17 is also involved in the pathogenesis of RA. When treating patients with both PsA and RA, it may be essential to consider the treatment strategy, depending on which disease is more active.

IL-17A Is the Critical Cytokine for Liver and Spleen Amyloidosis in Inflammatory Skin Disease

Systemic amyloidosis is recognized as a serious complication of rheumatoid arthritis or inflammatory bowel disease, but also of inflammatory skin disease. However, the detailed molecular mechanism of amyloidosis associated with cutaneous inflammation remains unclear, and therapeutic approaches are limited. Here, we investigated the pathophysiology of amyloidosis secondary to cutaneous inflammation and the therapeutic effects of Janus kinase (JAK) inhibitors by examining a mouse model of spontaneous dermatitis (KCASP1Tg mice). Moreover, KCASP1Tg mice were crossed with interleukin-17A (IL-17A) knockout mice to generate IL-17A-/KCASP1Tg and examine the role of IL-17A in amyloidosis under cutaneous inflammation. KCASP1Tg mice showed severe amyloid deposition in the liver and spleen. Increased serum-neutral fat levels and decreased lymphocyte production were observed in the spleen. Overproduction of amyloidosis was partially ameliorated by the administration of JAK inhibitors and was further improved in IL-17A-/KCASP1Tg mice. IL-17A-producing cells included CD4, gamma delta, and CD8 T cells. In summary, our results from the analysis of a mouse model of dermatitis revealed that skin-derived inflammatory cytokines can induce amyloid deposition in the liver and spleen, and that the administration of JAK inhibitors and, even more, IL-17A ablation, reduced amyloidosis. This study demonstrates that active control of skin inflammation is essential to prevent internal organ amyloidosis.

Therapeutic potential of targeting IL-1 family cytokines in chronic inflammatory skin diseases

The interleukin-1 (IL-1) family of cytokines is a central regulator of a myriad of immunological responses. It comprises several cytokines, including those belonging to the IL-1, IL-36 and IL-18 subfamilies, as well as IL-33. The IL-1 family primarily plays a role in orchestrating innate immune responses but also in adaptive immunity. Increased interest in the IL-1 family occurred following the discovery that dysregulation of IL-1 signalling underlies the pathogenesis of several monogenic auto-inflammatory diseases, characterized by sterile inflammation involving the skin and other organs. This also provided increased understanding of the role of innate immunity and the IL-1 family in polygenic auto-inflammatory skin conditions, such as neutrophilic dermatoses, as well as in some of the most common chronic inflammatory skin diseases, such as psoriasis or hidradenitis suppurativa. Several therapeutic agents have been developed to inhibit the IL-1 family members and their signalling pathways. These have shown therapeutic efficacy in several chronic inflammatory skin disorders. The aim of this review is to thoroughly describe the consequences of pathological dysregulation of IL-1, IL-33, IL-36, IL-18 pathways in dermatological conditions and to provide a forward-looking update on therapeutic strategies targeting signalling by IL-1 family cytokines.

Janus Kinase Inhibitors Ameliorated Gastrointestinal Amyloidosis and Hypoalbuminemia in Persistent Dermatitis Mouse Model

Malnutrition is not only regarded as a complication of rheumatoid arthritis and inflammatory bowel disease but also that of inflammatory skin disease; however, the mechanisms and efficacy of its treatment have not been elucidated. Using a mouse model of dermatitis, we investigated the pathophysiology of malnutrition in inflammatory skin conditions and efficacy of its treatment. We employed spontaneous skin inflammation mice models overexpressing human caspase-1 in the epidermal keratinocytes. Body weight, nutrition level, and α1-antitrypsin fecal concentration were measured. The gastrointestinal tract was histologically and functionally investigated. Fluorescein isothiocyanate (FITC)-dextran was forcibly fed on an empty stomach, and plasma FITC-dextran was measured. The treatment efficacy of antibodies against tumor necrosis factor-α (TNF-α) and interleukin (IL)-α/β as well as Janus kinase (JAK) inhibitors was investigated. Compared with wild-type littermates, the inflammatory skin mice models showed a lowered body weight, reduction of serum albumin level, amyloid deposition in the stomach, small intestine, and large intestine, and increased α1-antitrypsin fecal concentration. However, the plasma FITC-dextran was unchanged between the dermatitis models and wild-type littermates. The over-produced serum amyloid A1 in the liver was detected in the plasma in the dermatitis model. Antibodies against TNF-α and IL-α/β showed partial effects on amyloid deposition; however, JAK inhibitors improved gastrointestinal amyloidosis with the improvement of skin symptoms. Chronic dermatitis is closely related to secondary amyloidosis in the gastrointestinal tract, resulting in hypoalbuminemia. Therefore, active control of skin inflammation is essential for preventing gastrointestinal complications.

Vascular inflammation in moderate-to-severe atopic dermatitis is associated with enhanced Th2 response

BACKGROUND

In atopic dermatitis (AD), some studies have shown an association with increased cardiovascular disease in certain populations. However, other investigations found modest or no association. Despite conflicting results, molecular profiling studies in both AD skin and blood have demonstrated upregulation of atherosclerosis and cardiovascular risk-related markers. However, the underlying mechanisms connecting AD to vascular inflammation/atherosclerosis are unknown. In this study, we aim to determine factors associated with vascular inflammation/atherosclerosis in AD patients.

METHODS

We used 18-FDG PET-CT to characterize vascular inflammation in AD patients and healthy subjects. In parallel, we assessed their skin and blood immune profiles to determine AD-related immune biomarkers associated with vascular inflammation. We also assessed levels of circulating microparticles, which are known to be associated with increased cardiovascular risk.

RESULTS

We found significant correlations between vascular inflammation and Th2-related products in skin and blood of AD patients as well as atherosclerosis-related markers that were modulated by dupilumab. Circulating levels of endothelial microparticles were significantly higher in severe AD patients and tended to correlate with vascular inflammation assessed by PET-CT.

CONCLUSION

Vascular inflammation in AD is associated with enhanced Th2 response and clinical severity, which may explain cardiovascular comorbidities observed in select AD populations. Larger prospective studies are needed to further evaluate vascular inflammation and cardiovascular events and mortality in AD patients. Finally, as dupilumab treatment demonstrated significant modulation of atherosclerosis-related genes in AD patients compared to placebo, these data suggest that modulation of vascular inflammation with systemic treatment should be explored in patients with AD.

Pathophysiology of psoriasis: A review

Psoriasis is a complex chronic inflammatory skin disease caused by the dynamic interplay between multiple genetic risk foci, environmental risk factors, and excessive immunological abnormalities. Psoriasis affects approximately 2% of the population worldwide, and dramatic advances have been achieved in the understanding and treatment options for psoriasis. Recent progress in biological therapies has revealed the fundamental roles of tumor necrosis factor-α, interleukin (IL)-23p19, and the IL-17A axis together with skin-resident immune cells and major signal transduction pathways in the pathogenesis of psoriasis. In addition to IL-17-producing T helper17 cells, innate lymphoid cell (ILC)3 induces psoriasis rashes directly without T-cell/antigen interaction in response to the released antimicrobial peptides from activated keratinocytes and inflammatory cytokines. ILC3 typically expresses retinoic acid receptor-related orphan receptor gamma t in the nucleus, matures in the presence of IL-7 and IL-23, and produces IL-17 and IL-22. The number of ILC3s is increased in the blood, psoriasis rash, and even in nonrash areas of psoriatic skin. Psoriasis is significantly associated with cardiovascular disease, metabolic syndrome, and inflammatory disorders, particularly the severe type. The similarity of enterobacteria in the psoriasis gut to that in diabetic patients may be related to its pathogenesis. In the current review, we focus on the pathophysiology of psoriasis in the accelerated immunological inflammatory loop, danger signal from keratinocytes, and cytokines, particularly IL-17 and IL-23p19. In addition, pathophysiological speculation with regard to morphology has been supplemented. Finally, the differences and similarities between psoriasis and atopic dermatitis are discussed.

New Treatment Addressing the Pathogenesis of Psoriasis

Psoriasis is an immune cell-mediated inflammatory skin disease. The interleukin (IL)23/IL17 axis plays an important role in the development of psoriasis. The effectiveness of biologic treatments such as tumor necrosis factor (TNF)α inhibitors (infliximab, adalimumab, certolizumab pegol), IL23 inhibitors (ustekinumab, guselkumab, tildrakizumab, risankizumab), and IL17 inhibitors (secukinumab, ixekizumab, brodalumab) have verified these findings. Immune-related cells such as dendritic cells (DCs) and macrophages, in addition to Toll-like receptors and cytokines such as interferon (IFN)α, TNFα, IFNɤ, IL12, IL22, IL23, and IL17, are related to the pathogenesis of psoriasis. Here, we first review new insights regarding the pathogenesis of psoriasis, as it relates to DCs, Langerhans cells, macrophages, the signal transducer and activator of transcription 3 pathway, and aryl hydrocarbon receptor in cutaneous vascular endothelial cells. Based on these findings, we summarize currently available oral treatments and biologics. Furthermore, we describe a new treatment option including Janus kinase inhibitor, tyrosine kinase 2 inhibitor, modulator of sphingosine 1-phosphate receptor 1, and Rho-associated kinase 2 inhibitor.

Enhanced Inflammasome Activity in Patients with Psoriasis Promotes Systemic Inflammation

Psoriasis is linked to systemic inflammation and cardiovascular comorbidities, but studies of the underlying cellular mechanisms are lacking. The NLRP3 inflammasome is genetically associated with psoriasis, and its activation is increasingly linked with cardiovascular disease. In this study, we show that patients with psoriasis exhibited higher plasma levels of inflammasome-generated IL-1β and IL-18, without any correlation to skin lesion severity. Increased constitutive expression of the inflammasome sensors NLRP3, NLRP1, and AIM2 was found in peripheral blood cells of the patients and also of those with mild disease, and this was accompanied by an increased caspase-1 reactivity in the myeloid blood subsets. TNF-α was found to activate selectively the NLRP3 inflammasome without the requirement for a priming signal. TNF-α was found to signal through the TNFR‒caspase-8‒caspase-1 alternative inflammasome pathway, which proceeds independently of pyroptosis. Patients who received anti-TNF therapy had normalized plasma IL-1β and IL-18 levels as well as normalized caspase-1 reactivity. This was in contrast to the patients treated with methotrexate who exhibited persistent, increased caspase-1 reactivity. Thus, we show that the TNF-α-mediated activation of NLRP3 inflammasomes in patients with psoriasis may contribute to systemic inflammation. Anti-TNF therapy normalized inflammasome function, suggesting a mechanism for the cardiovascular risk‒reducing effect.

Skin Inflammation and Testicular Function: Dermatitis Causes Male Infertility via Skin-Derived Cytokines

The medical comorbidities including skin diseases are associated with male infertility. The most common cause of male infertility is the inability of testes to produce sperm; however, the influence of persistent dermatitis on testicular function has not been elucidated so far. We investigated the relationship between skin inflammation and impaired sperm production using a spontaneous dermatitis mouse model. We examined the breeding records of dermatitis mice and their wild-type littermates. Sperm count, motility, and viability were analyzed by direct microscopic observation and flow cytometry. In addition, testis and epididymis were histologically examined. Finally, sperm viability was evaluated in another dermatitis mouse model and in wild-type mice in which inflammatory cytokines were intraperitoneally administered. Compared to wild-type littermate mice, the number of children born was lower in mice with dermatitis. The body weight and testis size were decreased age-dependently. In the skin disease group, the sperm count and movement ratio were clearly decreased, and reduced sperm viability was observed. Histological examination revealed the detachment of Sertoli cells and reduced spermatogenesis. The fibrosis of epididymal stroma was severe, and it might affect defective sperm maturation in the epididymis. In addition, this phenomena was reproduced by a hapten applied dermatitis mouse model and the intraperitoneal administration of inflammatory cytokines. Once the skin is inflamed, inflammatory cytokines are produced and released, which may affect testicular and sperm function. Additional studies are needed to determine the relationship between male infertility and severe dermatitis in human.

Targeting L-type amino acid transporter 1 in innate and adaptive T cells efficiently controls skin inflammation

BACKGROUND

Psoriasis is a frequent inflammatory skin disease that is mainly mediated by IL-23, IL-1β, and IL-17 cytokines. Although psoriasis is a hyperproliferative skin disorder, the possible role of amino acid transporters has remained unexplored.

OBJECTIVE

We sought to investigate the role of the essential amino acid transporter L-type amino acid transporter (LAT) 1 (SLC7A5) in psoriasis.

METHODS

LAT1 floxed mice were crossed to Cre-expressing mouse strains under the control of keratin 5, CD4, and retinoic acid receptor-related orphan receptor γ. We produced models of skin inflammation induced by imiquimod (IMQ) and IL-23 and tested the effect of inhibiting LAT1 (JPH203) and mammalian target of rapamycin (mTOR [rapamycin]).

RESULTS

LAT1 expression is increased in keratinocytes and skin-infiltrating lymphocytes of psoriatic lesions in human subjects and mice. LAT1 deletion in keratinocytes does not dampen the inflammatory response or their proliferation, which could be maintained by increased expression of the alternative amino acid transporters LAT2 and LAT3. Specific deletion of LAT1 in γδ and CD4 T cells controls the inflammatory response induced by IMQ. LAT1 deletion or inhibition blocks expansion of IL-17-secreting γ4⁺δ4⁺ and CD4 T cells and dampens the release of IL-1β, IL-17, and IL-22 in the IMQ-induced model. Moreover, inhibition of LAT1 blocks expansion of human γδ T cells and IL-17 secretion by human CD4 T cells. IL-23 and IL-1β stimulation upregulates LAT1 expression and induces mTOR activation in IL-17⁺ γδ and T_H17 cells. Deletion or inhibition of LAT1 efficiently controls IL-23- and IL-1β-induced phosphatidylinositol 3-kinase/AKT/mTOR activation independent of T-cell receptor signaling.

CONCLUSION

Targeting LAT1-mediated amino acid uptake is a potentially useful immunosuppressive strategy to control skin inflammation mediated by the IL-23/IL-1β/IL-17 axis.

Psoriasis and the TNF/IL23/IL17 axis

The excellent response of psoriasis to anti-TNF-α(TNF)/IL23/IL17A biologics implies a crucial role for the TNF/IL23/IL17 axis in developing psoriasis. In addition to the TNF/IL23/IL17 axis provided by immune cells, current evidence points to an important contribution of TNF, IL23 and IL17C produced from non-hematopoietic keratinocytes. Therefore, crosstalk between immune cells and keratinocytes forms a multilayered feed-forward loop to accelerate the TNF/IL23/IL17A axis. Many biologics have already been licensed or are under clinical trials. Given that the IL-17 signature is more upregulated in the skin than in synovium in psoriatic arthritis, anti-IL-23/IL-17 agents seem to be superior to anti-TNF-α remedies in the treatment of skin lesions. In this review, we summarize recent topics in psoriasis and the TNF/IL23/IL17 axis.

Relationship of atopic dermatitis with stroke and myocardial infarction: A meta-analysis

BACKGROUND

Lots of previous reports have suggested a potential association of atopic dermatitis (AD) with stroke and myocardial infarction (MI). However, the result is still controversial, Consequently, we conducted this meta-analysis to estimate the relationship of AD with Stroke and MI.

METHODS

PubMed, Embase, and Web of Science databases were searched from inception to June 2018. Stroke and MI were considered as a composite endpoint. We calculated pooled hazard ratios (HRs) with 95% confidence intervals (CIs). Subgroup and sensitivity analysis were performed to assess the potential sources of heterogeneity of the pooled estimation.

RESULTS

A total of 12 articles with 15 studies involving 3,701,199 participants were included in this meta-analysis. Of these, 14 studies on stroke and 12 on MI. Pooled analysis showed participants with AD experienced a significant increased risk of stroke (combined HR, 1.15; 95% CI, 1.08-1.22; P = .000) and MI (combined HR, 1.13; 95% CI, 1.02-1.24; P = .014), compared with participants without AD. The risk of stroke and MI was significant both in male subjects (stroke: HR: 1.33, 95% CI: 1.14-1.56; MI: HR: 2.01, 95% CI: 1.31-3.08), but not in female subjects (HR: 1.02, 95% CI: 0.77-1.35; MI: HR: 0.98, 95% CI: 0.72-1.32). The results were more pronounced for ischemic stroke (HR: 1.16, 95% CI: 1.13-1.19) in the stratified with stroke type. Stratifying by AD type, the risk of stroke was significant in severe AD (HR: 1.29, 95% CI: 1.08-1.54) and moderate AD (HR: 1.11, 95% CI: 1.01-1.22) for MI.

CONCLUSIONS

AD is independently associated with an increased risk of stroke and MI, especially in male subjects and ischemic stroke and the risk is associated with the severity of AD.

Interleukin 1-β, interleukin-1 receptor antagonist and vitamin D levels in children with atopic dermatitis

Introduction

Among the broad spectrum of cytokines, interleukin 1-β (IL-1β) has been implicated in induction and subsequent aggravation of skin lesions in atopic dermatitis (AD). A considerable body of evidence suggests that vitamin D status also influences the risk and/or severity of AD.

Material and methods

Fifty-seven children suffering from mild to severe AD were enrolled in the study. The control group consisted of 33 matched healthy children. In all the children serum concentrations of IL-1β/IL-1F2 and the interleukin-1 receptor antagonist IL-Ra/1F3 were measured. Serum 25(OH)D concentration was obtained for 49 patients with AD and all healthy children.

Results

In children with AD 59.2% of children had insufficiency, 24.5% had deficiency and 16.3% had a sufficient serum 25(OH)D level. In the control group 26.5%, 52.9% and 20% of participants had insufficiency/deficiency/sufficiency of 25(OH)D, respectively. The severity of AD was positively correlated with total IgE level, percentage and absolute count of eosinophils and IL-1Ra. IL-1β correlated with IL-1Ra.

Conclusions

In children with AD the serum vitamin D level was lower than in healthy children. The correlation between severity of AD and IL-1Ra may prove that inflammasome-dependent IL-1β is involved in immunopathogenesis of the disease. Further studies are needed on a larger population of children to confirm the role of this cytokine in development of AD.

The association with cardiovascular disease and type 2 diabetes in adults with atopic dermatitis: a systematic review and meta-analysis

BACKGROUND

Recent studies examining the association between atopic dermatitis (AD) and cardiovascular disease (CVD) and type 2 diabetes have shown inconsistent results.

OBJECTIVES

To carry out a systematic review and meta-analysis that examines the association with cardiovascular disease and type 2 diabetes in adults with AD.

METHODS

We compared the risk of CVD and diabetes for adult patients with and without AD by searching the PubMed, Embase and Web of Science databases. Data extraction was carried out by two independent reviewers. We found a total of 2855 citations, of which 53 were considered relevant based on title and abstract. Overall, 16 publications were included in the qualitative analysis, of which 13 were also included in a quantitative meta-analysis of crude data.

RESULTS

No association was observed between AD and unspecified but suspected type 2 diabetes [pooled odds ratio (OR) 1·11; 95% confidence interval (CI) 0·87-1·42], hypertension (pooled OR 1·16; 95% CI 0·98-1·37), stroke (pooled OR 1·15; 95% CI 0·95-1·39) or myocardial infarction (pooled OR 1·14; 95% CI 0·83-1·56), but a positive association was observed with angina pectoris (OR 1·73; 95% CI 1·27-2·37). Meta-analysis of adjusted data gave similar results.

CONCLUSIONS

While adults with AD in some populations have an increased prevalence of cardiovascular risk factors, such as obesity and smoking, it is unlikely that AD represents an independent and clinically relevant risk factor for cardiometabolic disease.

Interleukin-17 alters the biology of many cell types involved in the genesis of psoriasis, systemic inflammation and associated comorbidities

Psoriasis is a chronic, immune-mediated, systemic inflammatory disease that is defined by a characteristic skin reaction produced when elevated levels of inflammatory cytokines such as interleukin (IL)-17 alter the growth and differentiation of skin cells. The pathogenesis of comorbid conditions associated with psoriasis, including psoriatic arthritis, cardiovascular disease, obesity, metabolic syndrome, liver disorders, renal disease and depression, is also largely affected by inflammation. In this review, we examine the effect of IL-17 on the inflammatory pathways in a variety of different cell types, including keratinocytes, as well as epithelial cells of the colon, kidney, gut and liver. Additionally, we investigate the role of IL-17 in mediating the psoriasis-associated comorbidities detailed above.

Atopic dermatitis and risk of hypertension, type 2 diabetes, myocardial infarction and stroke in a cross-sectional analysis from the Canadian Partnership for Tomorrow Project

BACKGROUND

Atopic dermatitis (AD) has been associated with cardiovascular risk factors and diseases, but epidemiological studies to date have found conflicting results.

OBJECTIVES

To determine the associations of AD with hypertension, type 2 diabetes (T2D), myocardial infarction (MI) and stroke.

METHODS

We conducted a cross-sectional analysis of baseline data from the Canadian Partnership for Tomorrow Project, which includes Canadian residents aged 30-74 years living in British Columbia, Alberta, Ontario, Quebec and the Atlantic Provinces. We excluded participants with incomplete data on AD, hypertension, T2D, MI or stroke, who had type 1 or gestational diabetes or who developed any of the outcomes at an age prior to a diagnosis of AD. This left 259 119 participants in our analysis. We used logistic regression to calculate age- and sex-, and multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) between AD and subsequent hypertension, T2D, MI and stroke.

RESULTS

AD was reported by 21 379 (8·4%) participants. In total, 52 787 cases of hypertension, 12 739 cases of T2D, 4390 cases of MI and 2235 cases of stroke were reported by participants at enrolment. In the multivariable-adjusted model, AD was associated with decreased odds of hypertension (OR 0·87, 95% CI 0·83-0·90), T2D (OR 0·78, 95% CI 0·71-0·84), MI (OR 0·87, 95% CI 0·75-1·00) and stroke (OR 0·79, 95% CI 0·66-0·95).

CONCLUSIONS

We did not find evidence of a positive association between AD and subsequent hypertension, T2D, MI or stroke; AD was inversely associated with these outcomes in our study. Given our findings and the conflicting literature, AD is likely not a major risk factor for cardiovascular disease.

Advances in atopic dermatitis in 2015

This review aims to highlight recently published articles on atopic dermatitis (AD). Updated are the insights into epidemiology, pathology, diagnostics, and therapy. Epidemiologic studies have revealed a positive correlation between AD and systemic conditions, such as rheumatoid arthritis, inflammatory bowel disease, and neonatal adiposity. Pathologic findings highlight the involvement of novel barrier factors (desmoplakin and claudin), novel immune cell subsets (pathogenic effector T_H2 cells and group 2 innate lymphoid cells), and differential skewing of helper T cells (eg, T_H17 dominance in Asians with AD). As diagnostics, noninvasive examinations of the transepidermal water loss of neonates, the density of epidermal Staphylococcus species, and the gut flora might prognosticate the onset of AD. As for therapy, various methods are proposed, including conventional (petrolatum and UV) and molecule-oriented regimens targeting Janus kinase, signal transducer and activator of transcription 3, extracellular signal-regulated kinase, sirtuin 1, or aryl hydrocarbon receptor.

"Inflammatory skin march" in atopic dermatitis and psoriasis

BACKGROUND

Comorbidities of cardiovascular diseases (CVDs), metabolic syndrome and autoimmune diseases with systemic inflammation are recent topics in medicine. Inflammatory skin diseases such as atopic dermatitis and psoriasis are an active source of diverse proinflammatory cytokines and chemokines, which are readily detectable in the circulation and are likely to be involved in developing comorbidities.

EVIDENCE

Both atopic dermatitis and psoriasis are frequently comorbid with CVD, metabolic syndrome and autoimmune diseases, the consequence of which is called "inflammatory skin march", "psoriatic march" or "march of psoriasis".

CONCLUSION

In this review, we summarize the epidemiological evidence and pathogenetic concepts regarding inflammatory skin march in atopic dermatitis and psoriasis.

Cardiovascular and Metabolic Diseases Comorbid with Psoriasis: Beyond the Skin

A close association of systemic inflammation with cardiovascular diseases and metabolic syndrome is recently a popular topic in medicine. Psoriasis is a chronic inflammatory skin disease with a prevalence of approximately 0.1-0.5% in Asians. It is characterized by widespread scaly erythematous macules that cause significant physical and psychological burdens for the affected individuals. The accelerated inflammation driven by the TNF-α/IL-23/IL-17A axis is now known to be the major mechanism in the development of psoriasis. Psoriasis is not a mere skin disease; it is significantly associated with cardiovascular diseases and metabolic syndrome, which suggests that the chronic skin inflammation extends the systemic inflammation beyond the skin. In this article, we review the epidemiological and pathological aspects of psoriasis and its comorbidities.