A genome-wide meta-analysis of palmoplantar pustulosis implicates TH2 responses and cigarette smoking in disease pathogenesis.

BACKGROUND: Palmoplantar pustulosis (PPP) is an inflammatory skin disorder that mostly affects smokers and manifests with painful pustular eruptions on the palms and soles. Although the disease can present with concurrent plaque psoriasis, TNF and IL-17/IL-23 inhibitors show limited efficacy. There is therefore a pressing need to uncover PPP disease drivers and therapeutic targets. OBJECTIVES: We sought to identify genetic determinants of PPP and investigate whether cigarette smoking contributes to disease pathogenesis. METHODS: We performed a genome-wide association meta-analysis of 3 North-European cohorts (n = 1,456 PPP cases and 402,050 controls). We then used the scGWAS program to investigate the cell-type specificity of the association signals. We also undertook genetic correlation analyses to examine the similarities between PPP and other immune-mediated diseases. Finally, we applied Mendelian randomization to analyze the causal relationship between cigarette smoking and PPP. RESULTS: We found that PPP is not associated with the main genetic determinants of plaque psoriasis. Conversely, we identified genome-wide significant associations with the FCGR3A/FCGR3B and CCHCR1 loci. We also observed 13 suggestive (P < 5 × 10-6) susceptibility regions, including the IL4/IL13 interval. Accordingly, we demonstrated a significant genetic correlation between PPP and TH2-mediated diseases such as atopic dermatitis and ulcerative colitis. We also found that genes mapping to PPP-associated intervals were preferentially expressed in dendritic cells and often implicated in T-cell activation pathways. Finally, we undertook a Mendelian randomization analysis, which supported a causal role of cigarette smoking in PPP. CONCLUSIONS: The first genome-wide association study of PPP points to a pathogenic role for deregulated TH2 responses and cigarette smoking.

Prevalence, incidence, mortality and healthcare resource use for generalized pustular psoriasis, palmoplantar pustulosis and plaque psoriasis in England: a population-based cohort study.

BACKGROUND: Generalized pustular psoriasis (GPP) and palmoplantar pustulosis (PPP) are chronic inflammatory skin conditions. Accumulating evidence shows that GPP and PPP have different characteristics to plaque psoriasis and are distinct clinical entities. OBJECTIVES: To assess the epidemiology, comorbidities, mortality and healthcare use for patients in England with GPP and PPP versus those with plaque psoriasis. METHODS: We carried out a cohort study involving analyses of longitudinal electronic health record data in the Clinical Practice Research Datalink Aurum database and linked hospital and mortality data between 2008 and 2019. The primary study outcome was the incidence and prevalence rates of GPP, PPP and plaque psoriasis in England. Secondary outcomes included survival rates and healthcare resource use (HCRU) by disease type. RESULTS: We identified 373 patients with GPP, 1828 with PPP and 224 223 with plaque psoriasis. Mean (SD) age was 55.9 (18.6) years for patients with GPP, 51.5 (16.4) years for those with PPP and 48.5 (19.1) years for those with plaque psoriasis; 62.5% and 65.9% of patients with GPP and PPP, respectively, were women, vs. 49.4% of those with plaque psoriasis. About half of patients were overweight or obese at baseline (GPP 48.6%, PPP 56.0%, plaque psoriasis 45.9%). The incidence rates for GPP, PPP and plaque psoriasis were 0.25 [95% confidence interval (CI) 0.21-0.28], 2.01 (95% CI 1.92-2.11) and 103.2 (95% CI 102.5-103.9) per 100 000 person-years, respectively. From 2008 to 2019, the prevalence rates per 100 000 persons ranged from 1.61 to 3.0 for GPP, from 1.1 to 18.7 for PPP and from 1771.0 to 1903.8 for plaque psoriasis. Survival rates were lower for patients with GPP, particularly those who were > 55 years of age and those with a history of one or more comorbidities in each cohort. HCRU was lower in the cohort with plaque psoriasis and highest in the cohort with GPP, particularly among those who had more than one GPP flare. CONCLUSIONS: Our results provide further evidence that, in England, GPP is a distinct disease with different epidemiology, lower survival and higher HCRU than plaque psoriasis.

There are several different forms of the inflammatory skin disease called psoriasis. Plaque psoriasis is characterized by flaky or scaly patches of skin. Generalized pustular psoriasis ('GPP') causes red skin and painful pustules. Palmoplantar pustulosis ('PPP') affects the palms and soles. In this study, we used electronic health record data from general practices that contribute to a database in England called the Clinical Practice Research Datalink (CPRD). We did this to find out how common plaque psoriasis, GPP and PPP are in England and understand how people use healthcare services. The number of patients with these conditions increased between 2008 and 2019. In 2019, the most frequent condition was plaque psoriasis, followed by PPP and GPP. Among people with GPP, 3 out of 5 were women, 7 out of 10 also had a diagnosis of plaque ­psoriasis and 7 out of 10 had other illnesses. Among people with PPP, about 2 out of 3 were women, 1 out of 3 also had a diagnosis of plaque psoriasis and 2 out of 3 had other illnesses. Overall survival was lowest for people with GPP, particularly those who were older than 55 years of age and those with other illnesses. We found that a higher proportion of patients with GPP were admitted to hospital and visited A&E than those with PPP or plaque psoriasis. These patients also had more outpatient and A&E visits every year. Our results suggest that GPP has a different epidemiology than plaque psoriasis, and patients with GPP use more healthcare services and have a higher mortality rate.

Epidermal growth factor receptor/mitogen-activated kinase inhibitor treatment induces a distinct inflammatory hair follicle response that includes collapse of immune privilege.

BACKGROUND: Inhibitors of epidermal growth factor receptor (EGFRi) or mitogen-activated kinase (MEKi) induce a folliculitis in 75-90% of patients, the pathobiology of which remains insufficiently understood. OBJECTIVES: To characterize changes in the skin immune status and global transcriptional profile of patients treated with EGFRi; to investigate whether EGFRi affects the hair follicle's (HF) immune privilege (IP); and to identify early proinflammatory signals induced by EGFRi/MEKi in human scalp HFs ex vivo. METHODS: Scalp biopsies were taken from patients exhibiting folliculitis treated long term with EGFRi ('chronic EGFRi' group, n = 9) vs. healthy scalp skin (n = 9) and patients prior to commencing EGFRi treatment and after 2 weeks of EGFRi therapy ('acute EGFRi' group, n = 5). Healthy organ-cultured scalp HFs were exposed to an EGFRi (erlotinib, n = 5) or a MEKi (cobimetinib, n = 5). Samples were assessed by quantitative immunohistomorphometry, RNA sequencing (RNAseq) and in situ hybridization. RESULTS: The 'chronic EGFRi' group showed CD8+ T-cell infiltration of the bulge alongside a partial collapse of the HF's IP, evidenced by upregulated major histocompatibility complex (MHC) class I, ß2-microglobulin (B2 M) and MHC class II, and decreased transforming growth factor-ß1 protein expression. Healthy HFs treated with EGFRi/MEKi ex vivo also showed partial HF IP collapse and increased transcription of human leucocyte antigen (HLA)-A, HLA-DR and B2 M transcripts. RNAseq analysis showed increased transcription of chemokines (CXCL1, CXCL13, CCL18, CCL3, CCL7) and interleukin (IL)-26 in biopsies from the 'chronic EGFRi' cohort, as well as increased IL-33 and decreased IL-37 expression in HF biopsies from the 'acute EGFRi' group and in organ-cultured HFs. CONCLUSIONS: The data show that EGFRi/MEKi compromise the physiological IP of human scalp HFs and suggest that future clinical management of EGFRi/MEKi-induced folliculitis requires HF IP protection and inhibition of IL-33.

About 75­90% of people with cancer who are treated with drugs called EGFR inhibitors (EGFRi) and MEK inhibitors (MEKi) will get a skin condition called folliculitis. This is where the hair follicles become inflamed. Despite this, the reasons why some patients develop this are not well understood. In this study, we had three goals. We wanted to understand how these medications alter the skin's immune response and genetic processes. We also wished to determine the impact of the medications on the immune protection of hair follicles. Finally, we wanted to find early signs of inflammation in hair follicles caused by the medications. We studied scalp samples from people who got folliculitis after long-term EGFRi treatment and compared them to samples of healthy scalp skin. We also examined patients before and after they began EGFRi treatment. In the lab, we exposed healthy hair follicles to an EGFRi called 'erlotinib' or a MEKi called 'cobimetinib'. We then carried out detailed imaging and genetic analyses. We found that long-term treatment with EGFRi increased certain immune cells (called CD8+ T cells) in the hair follicle area. This led to a breakdown in the immune protection around hair follicles. A similar breakdown was found in lab-treated healthy follicles. Genetic changes linked to inflammation were also found. Our findings suggest that EGFRi and MEKi treatments could affect the natural immune defence of hair follicles in the scalp and cause folliculitis. Protecting the immune system and controlling inflammation might be the key to treating people with these drug-related skin conditions.

The impact of irritant challenge on the skin barrier and myeloid-resident immune cells in women who are postmenopausal is modulated by hormone replacement therapy.

BACKGROUND: Sex hormone changes during menopausal transition contribute to declining skin health. However, how menopause and its treatment by hormone replacement therapy (HRT) impact the skin barrier and immune system is unclear. OBJECTIVES: To examine how menopause and HRT affect the skin barrier and immune cell composition in postmenopausal women following irritant challenge. METHODS: Two cohorts of postmenopausal women were recruited to the study. The first cohort consisted of 10 untreated women [HRT-; mean (SEM) age 56.5 (1.6) years (range 48-63)] and the second was composed of 8 women receiving HRT [HRT+; mean (SEM) age 54.0 (2.1) years (range 48-63)]. Skin irritation was induced by applying topical sodium lauryl sulfate (SLS) 1.25% to occluded buttock skin for 48 h. Clinical assessment was conducted after 24 h, followed by biopsy of both SLS-challenged and unchallenged skin for analysis of skin barrier proteins and immune cell distribution using immunofluorescence. RESULTS: Clinically, there were no significant differences in skin irritant responses between those taking or not taking HRT (including increased skin redness and blood flow). In response to SLS challenge a significant increase in transepidermal water loss (P < 0.05), filaggrin deposition and cytokeratin 10 (K10)+ cell layers (P < 0.01) was observed in individuals receiving HRT compared with the HRT- group. Following SLS challenge in individuals taking HRT, a significant (P < 0.01) reduction in CD207+ cells in the epidermis was observed, accompanied by an increase of CD207+ cells in the dermis, indicative of migrating Langerhans cells (LCs). Significantly fewer migrating LCs were found in those who were not receiving HRT (P < 0.01). Furthermore, the numbers of dermal dendritic cells (DCs), macrophages, and CD11c+CD206- and CD68+CD206- subsets were found to be significantly (P < 0.05) higher in those taking HRT following SLS challenge. CONCLUSIONS: Individuals receiving HRT displayed enhanced skin barrier response to SLS challenge with thicker filaggrin and increased K10+ epidermal cell layers. Following challenge, HRT users exhibited elevated LC, inflammatory DC and macrophage counts in the dermis. These may render skin both more prone to inflammation and more capable of resolving it, while also promoting skin repair.

Changes to a person's sex hormones during the menopause can affect the skin. The effects of the menopause on the immune system and the skin are still unclear. The effects of a treatment called 'hormone replacement therapy' ('HRT') are also still unclear. We investigated the effects of HRT on immune cells and skin barrier function in women who had been through the menopause. To do this, we compared the skin of two groups of women: those who were taking HRT and those who were not. Looking at skin redness and blood flow, we found that the two groups of women had a similar response to their skin being irritated by a chemical called 'SLS'. Yet, the women taking HRT had increased water loss from their skin after SLS was applied. We also found that after having SLS applied, women on HRT had a thicker layer of cells in the top section of their skin that produced more of a protein that helps protect the skin. Women taking HRT also had more inflammatory cells in the deeper layers of their skin after SLS was applied. Overall, our findings suggest that HRT may improve the skin's immune response to irritating substances. HRT could have an effect on the skin's ability to repair itself and on general skin health.

Implementing well-being in the management of psoriasis: An expert recommendation.

Psoriasis causes detriment in a person's physical, mental and social health which impairs their quality of life (QoL). However, the current psoriasis management may not adequately address all relevant health domains. Since the goal of healthcare is to restore or maintain health, health outcomes should include all areas of the patient's overall health. Life satisfaction, QoL and patient well-being are essential to a comprehensive approach to the disease. With the inclusion of more people-centred policies, care of patients with psoriasis should evolve towards a holistic and integrated assessment of the disease impact, including subjective measures of well-being in order to encompass all aspects of health. The main objective of this expert review is to give the concept of well-being a place as an entity within the holistic therapeutic approach for patients with psoriasis. Identifying and defining common goals beyond the skin with the patient and testing them throughout the course of treatment will benefit and enhance treatment success. We propose a series of recommendations for application in clinical practice, providing tangible clinical guidance for implementing well-being in the management of psoriasis. Among the recommendations are the need to initially listen to the patient, to know their level of empowerment or what they want to achieve, their preferences in decision making, the evaluation of not only the physical but also the emotional impact of the disease (well-being), the definition of the aspects that can generate a cumulative deterioration of the disease throughout life, and a continuous assessment of the patient's preferences with the opinion of the expert clinician and the integration of the knowledge of external clinical evidence.

Risk of serious infection and infection mortality in patients with psoriasis: A nationwide cohort study using the Taiwan National Health Insurance claims database.

BACKGROUND: The risks of serious infections that lead to hospitalization and mortality in patients with psoriasis in Asia have not been comprehensively studied. OBJECTIVES: We examined the incidence of serious infection and infection mortality in patients with psoriasis. METHODS: This population-based retrospective cohort study used the Taiwan National Health Insurance claims database from 2000 to 2017. Adult patients with psoriasis were identified by a relevant International Classification of Diseases (ICD) code and matched to six comparators without psoriasis on age and sex. Psoriasis patients were categorized as having moderate-to-severe disease once exposed to systemic therapies, phototherapy or biologic therapies. The incidence of serious infection and infection mortality were identified by ICD codes from inpatient hospitalization and death registration. Cox proportional hazard models were used to compare the risk, and the results were adjusted for covariates and presented as adjusted hazard ratios (aHR) and 95% confidence interval (95% CI). RESULTS: Overall, 185,434 psoriasis patients and 1,112,581 comparators were included. A higher rate of serious infection (aHR: 1.21, 95% CI: 1.19-1.22) was found in patients with psoriasis compared to matched comparators without psoriasis, and the risk was enhanced when patients had moderate-to-severe psoriasis (aHR: 1.30, 95% CI: 1.27-1.34). Specifically, there was an increased risk of serious infection due to respiratory infections (aHR: 1.11, 95% CI: 1.09-1.13), skin/soft-tissue infections (aHR: 1.57, 95% CI: 1.52-1.62), sepsis (aHR: 1.23, 95% CI: 1.19-1.27), urinary tract infections (aHR: 1.11, 95% CI: 1.08-1.14), hepatitis B (aHR: 1.18, 95% CI: 1.06-1.30) and hepatitis C (aHR: 1.49, 95% CI: 1.32-1.69). Furthermore, psoriasis patients were associated with a higher risk of infection-related mortality (aHR: 1.15, 95% CI: 1.11-1.18) compared to matched comparators. CONCLUSION: Patients with psoriasis had a higher risk of serious infection and infection mortality, which was enhanced by moderate-to-severe psoriasis. Practitioners should be aware of the increased risk in patients with psoriasis, but it should not be a barrier to offering effective treatment.

Benefits Over Five Years of Ixekizumab Treatment in Patients With Psoriasis Involving Challenging Body Areas.

BACKGROUND: Psoriasis involving challenging body areas, such as the scalp, face, palmoplantar surfaces, or nails, can be challenging to treat and negatively affects patient outcomes. OBJECTIVE: To assess clear responses and cumulative clinical benefits over 5 years of ixekizumab treatment of moderate-to-severe plaque psoriasis in patients with and without baseline involvement of challenging body areas. METHODS: This post hoc analysis included patients treated with ixekizumab in the UNCOVER-3 trial. We assessed PASI100 responses through the week (W) 264 and cumulative clinical benefits at W264 (calculated as least-squares mean of the percentage of maximum area under the curve for PASI100 and PASI% improvement and expressed as cumulative clearance days). Statistical differences were calculated via ANCOVA. RESULTS: A total of 385 patients were analyzed: 349 with scalp involvement, 152 with facial involvement, 96 with palmoplantar involvement, and 229 with nail involvement. Proportions of patients achieving PASI100 were numerically similar between patients with and without scalp and nail involvement. More patients without facial and palmoplantar involvement achieved PASI100 at W60 (only palmoplantar), W108, W156, W204, and W264 (only palmoplantar). At W264, cumulative clinical benefits for PASI100 and PASI% improvement were high and similar in both patient groups, with and without challenging body areas. A significant difference (P=0.006) was only observed for PASI% improvement between patients with and without nail involvement. CONCLUSION: For most efficacy measures, patients treated with ixekizumab over 5 years achieved similar clear responses and cumulative clinical benefits regardless of baseline involvement of challenging body areas. J Drugs Dermatol. 2024;23(8):619-625.  doi:10.36849/JDD.8160.

Integrated proteomics and genomics analysis of paradoxical eczema in psoriasis patients treated with biologics.

BACKGROUND: Few studies have explored the immunology and genetic risk of paradoxical eczema occurring as an adverse event of biologic therapy in patients with psoriasis. OBJECTIVES: We sought to describe the systemic inflammatory signature of paradoxical eczema using proteomics and explore whether this is genetically mediated. METHODS: This study used the Olink Target 96 Inflammation panel on 256 serum samples from 71 patients with psoriasis and paradoxical eczema, and 75 controls with psoriasis to identify differentially expressed proteins and enriched gene sets. Case samples from 1 or more time points (T1 prebiologic, T2 postbiologic, and T3 postparadoxical eczema) were matched 1:1 with control samples. Genes contributing to enriched gene sets were selected, and functional single nucleotide polymorphisms used to create polygenic risk scores in a genotyped cohort of 88 paradoxical eczema cases and 3124 psoriasis controls. RESULTS: STAMBP expression was lower in cases at T1 than in controls (log-fold change: -0.44; adjusted P = .022); no other proteins reached statistical significance at equivalent time points. Eleven gene sets including cytokine and chemokine pathways were enriched in cases at T2 and 10 at T3. Of the 39 proteins contributing to enriched gene sets, the majority are associated with the atopic dermatitis serum proteome. A polygenic risk score including 38 functional single nucleotide polymorphisms linked to enriched gene sets was associated with paradoxical eczema (adjusted P = .046). CONCLUSIONS: The paradoxical eczema systemic inflammatory proteome trends toward atopic dermatitis at a gene-set level and is detectable before onset of the phenotype. This signature could be genetically determined.

Characteristics associated with poor COVID-19 outcomes in people with psoriasis, psoriatic arthritis and axial spondyloarthritis: data from the COVID-19 PsoProtect and Global Rheumatology Alliance physician-reported registries.

OBJECTIVES: To investigate factors associated with severe COVID-19 in people with psoriasis (PsO), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). METHODS: Demographic data, clinical characteristics and COVID-19 outcome severity of adults with PsO, PsA and axSpA were obtained from two international physician-reported registries. A three-point ordinal COVID-19 severity scale was defined: no hospitalisation, hospitalisation (and no death) and death. ORs were estimated using multivariable ordinal logistic regression. RESULTS: Of 5045 cases, 18.3% had PsO, 45.5% PsA and 36.3% axSpA. Most (83.6%) were not hospitalised, 14.6% were hospitalised and 1.8% died. Older age was non-linearly associated with COVID-19 severity. Male sex (OR 1.54, 95% CI 1.30 to 1.83), cardiovascular, respiratory, renal, metabolic and cancer comorbidities (ORs 1.25-2.89), moderate/high disease activity and/or glucocorticoid use (ORs 1.39-2.23, vs remission/low disease activity and no glucocorticoids) were associated with increased odds of severe COVID-19. Later pandemic time periods (ORs 0.42-0.52, vs until 15 June 2020), PsO (OR 0.49, 95% CI 0.37 to 0.65, vs PsA) and baseline exposure to TNFi, IL17i and IL-23i/IL-12+23i (OR 0.57, 95% CI 0.44 to 0.73; OR 0.62, 95% CI 0.45 to 0.87; OR 0.67, 95% CI 0.45 to 0.98; respectively; vs no disease-modifying antirheumatic drug) were associated with reduced odds of severe COVID-19. CONCLUSION: Older age, male sex, comorbidity burden, higher disease activity and glucocorticoid intake were associated with more severe COVID-19. Later pandemic time periods, PsO and exposure to TNFi, IL17i and IL-23i/IL-12+23i were associated with less severe COVID-19. These findings will enable risk stratification and inform management decisions for patients with PsO, PsA and axSpA during COVID-19 waves or similar future respiratory pandemics.

Acrodermatitis continua of Hallopeau and generalised pustular psoriasis: Should they be the same or different entities?

Pustular psoriasis is characterised by eruptions of neutrophilic sterile pustules. The European Rare and Severe Psoriasis Expert Network consensus defines pustular psoriasis into three subtypes; generalised pustular psoriasis (GPP), palmoplantar pustulosis and acrodermatitis continua of Hallopeau (ACH). Mixed forms are categorised according to their predominant features. However, the Japanese Dermatological Association includes ACH under the diagnosis of GPP. This article aims to review the similarities and differences between ACH and GPP. Based on our review, interleukin (IL)-36RN mutations, the most frequent genetic findings in pustular psoriasis are found most commonly in GPP, followed by ACH. Genotypes of IL-36RN mutations among GPP patients and ACH patients are different between European and Asian ethnicities. IL-36 signalling pathway is the main mechanism. Metabolic diseases are common comorbidities and joint involvement can occur in 20.5%-36.4% of both conditions. Associated plaque psoriasis is more common in GPP than in ACH. Generally, ACH, even the generalised type, does not have systemic inflammation whereas GPP can occur with or without systemic inflammation. ACH can occur before, simultaneously, or after the development of GPP. However, response to treatment for GPP and ACH even in the same patients appear to be different. ACH seemed to be more recalcitrant to treatment than GPP but severe flare of GPP can lead to morbidity and mortality. Although GPP and ACH share genotypes and pathogenesis, we believe that ACH should be classified separately from GPP, and not under diagnosis of GPP. Future research is warranted to satisfactorily distinguish the two conditions.

Imsidolimab, an anti-interleukin-36 receptor monoclonal antibody, for the treatment of generalized pustular psoriasis: results from the phase II GALLOP trial.

BACKGROUND: Generalized pustular psoriasis (GPP) is a systemic inflammatory disease that can be severe, debilitating and life threatening. Uncontrolled activation of interleukin (IL)-36 proinflammatory activity may underlie the pathogenesis of GPP. Currently, GPP-specific treatment options are limited. OBJECTIVES: To evaluate the efficacy and safety of the anti-IL-36 receptor antibody imsidolimab in patients with GPP. METHODS: In an open-label, single-arm, multiple-dose study, patients with GPP were treated with imsidolimab to assess clinical efficacy, tolerability and safety. Patients received an intravenous dose of imsidolimab 750 mg on day 1, followed by three subcutaneous doses of imsidolimab 100 mg administered on days 29, 57 and 85. The primary efficacy endpoint was the proportion of patients who achieved a clinical response at weeks 4 and 16 following treatment with imsidolimab, as measured by the Clinical Global Impression scale. RESULTS: Eight patients were enrolled and six completed the study. Responses were observed as early as day 3, most rapidly for pustulation relative to other manifestations of GPP, with continued and consistent improvement across multiple efficacy assessments at day 8, day 29 and through day 113. Most treatment-emergent adverse events (TEAEs) were mild to moderate in severity. No patient discontinued the study owing to a nonserious TEAE. Two patients experienced serious adverse events (SAEs); no deaths were reported. CONCLUSIONS: Imsidolimab demonstrated a rapid and sustained resolution of symptoms and pustular eruptions in patients with GPP. It was generally well tolerated, with an acceptable safety profile, and is advancing to phase III trials. These data support the targeting of IL-36 signalling with a specific antibody - imsidolimab - as a therapeutic option for this severely debilitating condition.

Uptake of tumour necrosis factor-alpha inhibitor biosimilars for psoriasis: a drug utilization study from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR).

BACKGROUND: Tumour necrosis factor-alpha inhibitors (TNFi) have revolutionized the treatment of moderate-to-severe psoriasis. Following patent expiry of the originator biologics, TNFi biosimilars became available, presenting the opportunity for significant reductions in drug costs. OBJECTIVES: To describe the uptake of TNFi biosimilars for psoriasis treatment in the UK and Ireland. METHODS: This observational cohort study utilizes data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR), a national pharmacovigilance study register for patients with psoriasis on systemic treatments. We analysed biosimilar uptake trends over time in nine geographical regions of England along with Wales, Scotland, Northern Ireland and the Republic of Ireland. We assessed the incidence of switching to biosimilars in an originator-user cohort (switchers). Patients on originators infliximab, etanercept and adalimumab at the time originator patents expired, entered the cohort on 1 February 2015, August 2015 and October 2018, respectively, and were followed up until 31 October 2021. Trends in biosimilar initiations were assessed in an adalimumab-naïve cohort who started adalimumab between 1 October 2018 and 31 July 2019 (starters). We assessed the associations between patient factors and originator-to-biosimilar switching and biosimilar initiation using a multivariable Cox regression model and a multivariable logistic regression model, respectively. RESULTS: Included in the originator-user cohort were 4202 patients (209 on infliximab, 742 on etanercept and 3251 on adalimumab). For infliximab, etanercept and adalimumab, respectively, the cumulative incidence of originator-to-biosimilar switching increased with time to 14.8%, 23.6% and 66.6% after 3 years. Across geographical regions, 3-year switching rates varied from 0% to 43.7% for infliximab; from 0% to 40.4% for etanercept; and from 12.5% to 84.3% for adalimumab. Out of the 528 patients included in the adalimumab-naïve cohort, 67.8% started on biosimilars. Originator-to-biosimilar switching and biosimilar initiation were more common in men and in patients who had lower Psoriasis Area and Severity Index at cohort entry. CONCLUSIONS: The uptake of biosimilars increased over time and varied considerably across the UK and Ireland; adalimumab had the highest biosimilar uptake rate compared with that of other TNFi drugs.

Incidence and prevalence of generalized pustular psoriasis in multiethnic Johor Bahru, Malaysia: a population-based cohort study using routinely captured electronic health records in the Teleprimary Care (TPC®) clinical information system from 2010 to 2020.

BACKGROUND: There is limited understanding of the epidemiology of generalized pustular psoriasis (GPP) internationally, with no population-based estimates of GPP in South East Asia. OBJECTIVES: To determine the incidence and prevalence of GPP in the Malaysian population and characterize its flares and trigger factors. METHODS: We conducted a population-based cohort study using the Teleprimary Care database between January 2010 and December 2020. We identified 230 dermatologist-confirmed GPP cases using International Classification of Diseases, 10th revision, diagnostic codes. Annual prevalence and incidence rates were stratified by age, sex and ethnicity. We compared data regarding flares and trigger factors for patients with GPP who had associated psoriasis vulgaris (PV) with those who did not have associated PV. RESULTS: The prevalence of GPP was 198 per million (267 women, 127 men) and incidence was 27.2 per million person-years [95% confidence interval (CI) 22.8-31.6]; 35.3 (28.4-42.2) per million person-years for women and 18.3 (13.1-23.5) per million person-years for men. Rates were higher in Chinese individuals [prevalence 271 per million; incidence 41.6 per million person-years (28.9-54.3)] than in the Malay population [prevalence 186; incidence 24.6 (19.4-29.7)] or the Indian ethnic group [prevalence 179; incidence 25.0 (13.8-36.3)]. Annual prevalence was consistently higher in women than in men and highest among the Chinese population, followed by the Indian and Malay populations. Overall, 67% of patients with GPP had associated PV. The prevalence and incidence of GPP without PV were lower than GPP with PV at 66 vs. 132 per million and 19.3 (95% CI 15.6-23.0) vs. 8.0 (95% CI 5.6-10.3) per million person-years, respectively. The mean age at GPP onset was 42.7 years (SD 18.4). A bimodal trend in the age of GPP onset was observed, with first and second peaks at age 20-29 years and age 50-59 years, respectively. Disease onset was significantly earlier in patients with GPP without PV than in those with PV [mean age 37.5 years (SD 20.7) vs. 44.9 years (SD 17.0), P = 0.026]. Flares occurred more frequently in patients without PV than in those with PV [mean number of flares per patient per year was 1.35 (SD 0.77) vs. 1.25 (SD 0.58), P = 0.039]. Common triggers of flares in patients with GPP who did not have PV were infections, pregnancy, menstruation and stress, whereas withdrawal of therapy, particularly systemic corticosteroids, was a more frequent trigger in patients with GPP who also had PV. CONCLUSIONS: Our findings contribute to the global mapping of GPP, which will help inform the management of this rare condition.

The effect of immunomodulators on seroconversion after BNT162b2 and AZD1222 vaccines in patients with immune-mediated inflammatory diseases: a prospective cohort study.

BACKGROUND: Biologic and nonbiologic immunomodulators, used to treat immune-mediated inflammatory diseases (IMIDs), could impair the immune response to COVID-19 vaccines and thus vaccine effectiveness. OBJECTIVES: Our objective was to investigate the association between biologic and nonbiologic immunomodulators and seroconversion following the first and second dose of COVID-19 vaccines in patients with IMIDs. METHODS: Serum samples were collected following the first or second dose of the BNT162b2 or AZD1222 vaccines from patients receiving biologic and/or nonbiologic immunomodulators for one or more of psoriasis, psoriatic arthritis, rheumatoid arthritis, inflammatory bowel disease or systemic lupus erythematosus. Seroconversion was defined as a positive Roche Elecsys® Anti-SARS-CoV-2 S (spike protein subunit S1/receptor binding domain) immunoassay (≥ 0.8 U mL-1). Association between immunomodulator exposure and seroconversion was assessed using logistic regression, adjusting for age and sex. RESULTS: After excluding those with prior COVID-19, post-first vaccine dose samples from 193 participants and post-second dose samples from 312 participants were included in the analysis. Following the first vaccine dose, 17.6% (n = 34) of participants did not seroconvert. Seroconversion was reduced for those on nonbiologic [adjusted odds ratio (OR) 0.29, 95% confidence interval (CI) 0.12-0.69] or combined nonbiologic and biologic treatment (adjusted OR 0.14, 95% CI 0.045-0.45) compared with those on biologic monotherapy. Subgroup analysis demonstrated reduced odds of seroconversion in those on methotrexate (adjusted OR 0.097, 95% CI 0.19-0.49) or prednisolone treatment (adjusted OR 0.044, 95% CI 0.002-1.00) relative to tumour necrosis factor-α inhibitor monotherapy. No participants receiving rituximab (n < 5) seroconverted after the first vaccine dose. Following the second vaccine dose, 1.6% of all participants did not seroconvert. Non-seroconversion was associated with receiving rituximab (n = 3 of 4) compared with those receiving other therapies (n = 2 of 308, P < 0.001). Post hoc analyses demonstrated that non-seroconversion was associated with age [adjusted OR 0.18, 95% CI 0.037-0.93 for those aged 60 years and over (reference category age 18-39 years)], but not sex, ethnicity or vaccine type. CONCLUSIONS: Treatment with nonbiologics, particularly methotrexate, is associated with impaired seroconversion following two BNT162b2 or AZD1222 vaccine doses, in patients with IMIDs. These findings are consistent with those of other published studies. While this could indicate reduced protection against COVID-19, the immunological parameters that correlate most closely with vaccine effectiveness need to be defined to reach this conclusion.

Access to psoriasis treatment in Brazil and Chile: A cross-sectional multicentre Global Healthcare Study on Psoriasis.

BACKGROUND: Sufficient data on access to systemic treatment for patients with psoriasis living in Latin America (LA) including Brazil and Chile are lacking. Understanding the availability and limiting factors of access to treatments can help to improve patient care and decrease long-term healthcare costs. OBJECTIVES: In association with the Global Psoriasis Atlas, this cross-sectional survey study analysed the availability and insurance reimbursement of systemic treatments for adult patients with psoriasis in Brazil and Chile. METHODS: A multicentre, cross-sectional Global Healthcare Study on Psoriasis was performed in Brazil and Chile in 2020. For each eligible adult patient with psoriasis, doctors and nurses completed a 48-item questionnaire about clinical aspects of psoriasis including the Psoriasis Area Severity Index (PASI), body surface area (BSA) score and the Dermatology Life Quality Index (DLQI), as well as the availability of systemic treatments and insurance reimbursement status. Between-country differences were compared with Wilcoxon rank sum tests for continuous variables, and a χ2-test or Fisher's exact test, where appropriate, for categorical variables. The median and interquartile range (IQR) was calculated for non-normal distributed data. RESULTS: A total of 1424 patients with psoriasis from 43 centres [27 centres in Brazil (n = 826) and 16 in Chile (n = 598)], were included with a mean (SD) age of 49.1 (16.3) and 49.2 (15.1) years, respectively. Unstratified analyses revealed that patients with psoriasis in Chile had more severe disease than those in Brazil [PASI 11.6 vs. 8.4 (P < 0.001) and BSA 14.7 vs. 12.0 (P = 0.003), respectively]. For patients with moderate-to-severe psoriasis, defined as PASI and/or BSA ≥ 10, systemic nonbiologic drugs were available (81.2% in Brazil and 65.3% in Chile, P ≤ 0.001), but only 37.0% of patients in Brazil and 27.3% in Chile received biologics (P = 0.01). Lack of availability and/or lack of insurance reimbursement for biologic drugs for patients with moderate-to-severe psoriasis was reported for 22.2% (50 of 225) in Brazil and 67.9% (148 of 218) in Chile (P < 0.001). Patients with no access to biologic therapies due to lack of availability/insurance reimbursement had a median PASI of 9.15 (IQR 3.00-14.25) in Brazil and 12.0 (IQR 5.00-19.00) in Chile (P = 0.007), as well as a median BSA of 7.0 (IQR 3.00-15.00) and 12.0 (IQR 5.00-22.50) (P = 0.002), and median DLQI of 11.0 (6.00-15.00) and 21.0 (6.50-25.00) (P = 0.007), respectively. CONCLUSIONS: Chilean patients had significantly more severe psoriasis compared with Brazilian patients in our study. While nonbiologic treatments for moderate-to-severe psoriasis were available in both LA countries, there is a high need for improvement in access to more effective psoriasis treatments including biologics. Our results highlight a significant gap between treatment recommendations in international psoriasis guidelines and real-world situations in Brazil and Chile.

Nonadherence to systemic immune-modifying therapy in people with psoriasis during the COVID-19 pandemic: findings from a global cross-sectional survey.

BACKGROUND: Nonadherence to immune-modifying therapy is a complex behaviour which, before the COVID-19 pandemic, was shown to be associated with mental health disorders in people with immune-mediated diseases. The COVID-19 pandemic has led to a rise in the global prevalence of anxiety and depression, and limited data exist on the association between mental health and nonadherence to immune-modifying therapy during the pandemic. OBJECTIVES: To assess the extent of and reasons underlying nonadherence to systemic immune-modifying therapy during the COVID-19 pandemic in individuals with psoriasis, and the association between mental health and nonadherence. METHODS: Online self-report surveys (PsoProtectMe), including validated screens for anxiety and depression, were completed globally during the first year of the pandemic. We assessed the association between anxiety or depression and nonadherence to systemic immune-modifying therapy using binomial logistic regression, adjusting for potential cofounders (age, sex, ethnicity, comorbidity) and country of residence. RESULTS: Of 3980 participants from 77 countries, 1611 (40.5%) were prescribed a systemic immune-modifying therapy. Of these, 408 (25.3%) reported nonadherence during the pandemic, most commonly due to concerns about their immunity. In the unadjusted model, a positive anxiety screen was associated with nonadherence to systemic immune-modifying therapy [odds ratio (OR) 1.37, 95% confidence interval (CI) 1.07-1.76]. Specifically, anxiety was associated with nonadherence to targeted therapy (OR 1.41, 95% CI 1.01-1.96) but not standard systemic therapy (OR 1.16, 95% CI 0.81-1.67). In the adjusted model, although the directions of the effects remained, anxiety was not significantly associated with nonadherence to overall systemic (OR 1.20, 95% CI 0.92-1.56) or targeted (OR 1.33, 95% CI 0.94-1.89) immune-modifying therapy. A positive depression screen was not strongly associated with nonadherence to systemic immune-modifying therapy in the unadjusted (OR 1.22, 95% CI 0.94-1.57) or adjusted models (OR 1.14, 95% CI 0.87-1.49). CONCLUSIONS: These data indicate substantial nonadherence to immune-modifying therapy in people with psoriasis during the pandemic, with attenuation of the association with mental health after adjusting for confounders. Future research in larger populations should further explore pandemic-specific drivers of treatment nonadherence. Clear communication of the reassuring findings from population-based research regarding immune-modifying therapy-associated adverse COVID-19 risks to people with psoriasis is essential, to optimize adherence and disease outcomes.

Prevalence, comorbidities and mortality of generalized pustular psoriasis: A literature review.

Generalized pustular psoriasis (GPP) is a rare auto-inflammatory skin disease characterised by acute episodes of sterile pustule formation. Diagnosis and treatment of the disease have historically been complicated by a lack of awareness, and no consistent global definition or clinical coding standards. Now acknowledged as a distinct clinical entity with a recognised genetic component, GPP can take a serious and life-threatening course due to systemic inflammatory complications and its association with various comorbidities. As with other rare diseases, there are significant challenges to understanding the epidemiology of GPP, notably a small patient population, non-standardised study methodologies and ethnic differences in its presentation. A clearer understanding of GPP is therefore required for clinicians to better manage patients with this rare condition. In this review article, we present an overview of the available data on GPP prevalence estimates in key demographics and report the frequency of genetic mutations associated with the disease. We detail the incidence of known comorbidities and summarise the data on mortality and assigned causes of death. Lastly, we discuss the various factors that impact the collection, interpretation and comparison of these data.

Single-cell analysis implicates TH17-to-TH2 cell plasticity in the pathogenesis of palmoplantar pustulosis.

BACKGROUND: Palmoplantar pustulosis (PPP) is a severe inflammatory skin disorder characterized by eruptions of painful, neutrophil-filled pustules on the palms and soles. Although PPP has a profound effect on quality of life, it remains poorly understood and notoriously difficult to treat. OBJECTIVE: We sought to investigate the immune pathways that underlie the pathogenesis of PPP. METHODS: We applied bulk and single-cell RNA sequencing (RNA-Seq) methods to the analysis of skin biopsy samples and peripheral blood mononuclear cells. We validated our results by flow cytometry and immune fluorescence microscopy RESULTS: Bulk RNA-Seq of patient skin detected an unexpected signature of T-cell activation, with a significant overexpression of several TH2 genes typically upregulated in atopic dermatitis. To further explore these findings, we carried out single-cell RNA-Seq in peripheral blood mononuclear cells of healthy and affected individuals. Memory CD4+ T cells of PPP patients were skewed toward a TH17 phenotype, a phenomenon that was particularly significant among cutaneous lymphocyte-associated antigen-positive skin-homing cells. We also identified a subset of memory CD4+ T cells that expressed both TH17 (KLRB1/CD161) and TH2 (GATA3) markers, with pseudotime analysis suggesting that the population was the result of TH17 to TH2 plasticity. Interestingly, the GATA3+/CD161+ cells were overrepresented among the peripheral blood mononuclear cells of affected individuals, both in the single-cell RNA-Seq data set and in independent flow cytometry experiments. Dual-positive cells were also detected in patient skin by immune fluorescence microscopy. CONCLUSIONS: PPP is associated with complex T-cell activation patterns and may explain why biologic drugs that target individual T helper cell populations have shown limited therapeutic efficacy.

Exploring Mast Cell-CD8 T Cell Interactions in Inflammatory Skin Diseases.

The skin is exposed to environmental challenges and contains skin-resident immune cells, including mast cells (MCs) and CD8 T cells that act as sentinels for pathogens and environmental antigens. Human skin MCs and their mediators participate in the maintenance of tissue homeostasis and regulate the recruitment and activity of immune cells involved in the pathogenesis of skin diseases. The cutaneous CD8 T cell compartment is comprised of long-persisting resident memory T cells (TRM) and migratory or recirculating cells; both populations provide durable site immune surveillance. Several lines of evidence indicate that MC-derived products, such as CCL5 and TNF-α, modulate the migration and function of CD8 T cells. Conversely, activated CD8 T cells induce the upregulation of MC costimulatory molecules. Moreover, the close apposition of MCs and CD8 T cells has been recently identified in the skin of several dermatoses, such as alopecia areata. This review outlines the current knowledge about bidirectional interactions between human MCs and CD8 T cells, analyses the alteration of their communication in the context of three common skin disorders in which these cells have been found altered in number or function-psoriasis, atopic dermatitis, and vitiligo-and discusses the current unanswered questions.

Psoriasis.

Psoriasis is a common, chronic papulosquamous skin disease occurring worldwide, presenting at any age, and leading to a substantial burden for individuals and society. It is associated with several important medical conditions, including depression, psoriatic arthritis, and cardiometabolic syndrome. Its most common form, chronic plaque or psoriasis vulgaris, is a consequence of genetic susceptibility, particularly in the presence of the HLA-C*06:02 risk allele, and of environmental triggers such as streptococcal infection, stress, smoking, obesity, and alcohol consumption. There are several phenotypes and research has separated pustular from chronic plaque forms. Immunological and genetic studies have identified IL-17 and IL-23 as key drivers of psoriasis pathogenesis. Immune targeting of these cytokines and of TNFα by biological therapies has revolutionised the care of severe chronic plaque disease. Psoriasis cannot currently be cured, but management should aim to minimise physical and psychological harm by treating patients early in the disease process, identifying and preventing associated multimorbidity, instilling lifestyle modifications, and employing a personalised approach to treatment.