Insights into hidradenitis suppurativa

High-throughput proteomics identifies inflammatory proteins associated with disease severity and genetic ancestry in patients with hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition with a greater prevalence and disease burden in patients who identify as African American and those with a family history of HS, suggesting a strong genetic component to its pathogenesis.

OBJECTIVES

To evaluate the relationship between plasma inflammatory protein expression, HS disease severity and genetic ancestry in a diverse cohort of patients with HS.

METHODS

We performed a case-control, single-centre study of patients with HS and age-, sex- and ethnicity-matched healthy control participants. We profiled circulating inflammatory proteins using Olink® high-throughput proteomics and determined genetic ancestry from whole-genome sequencing data.

RESULTS

Using linear regression, we identified novel proteins associated with HS, after adjusting for age, sex and ethnicity. Our analysis also revealed differences in the inflammatory proteome linked to disease severity. Specifically, we found that plasma levels of interleukin (IL)-6 can distinguish between different Hurley stages, indicating that IL-6 may serve as a marker of disease severity. Additionally, we found variations in inflammatory protein levels based on genetic ancestry: patients with predominantly African ancestry exhibited higher levels of inflammatory proteins associated with neutrophilic inflammation, while those with predominantly European ancestry showed increased levels of T helper 1-related inflammatory proteins.

CONCLUSIONS

Although we were unable to account for treatment status or comorbidities that may influence the level of inflammatory cytokines, genetic ancestry and disease severity may influence the plasma inflammatory profile in patients with HS.

Comparing antibiotic prescribing patterns for hidradenitis suppurativa between the emergency department and ambulatory care setting

BACKGROUND

Oral antibiotics are a mainstay of treatment for hidradenitis suppurativa (HS), primarily due to their anti-inflammatory and anti-microbial properties. There is a paucity of literature comparing how antibiotic prescribing patterns for HS patients differ between the emergency department (ED) and ambulatory care settings.

OBJECTIVE

This study aims to compare antibiotic prescribing patterns for HS patients in the ED versus ambulatory care setting.

METHODS

We utilized the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) to identify visits for HS patients in 2005-2016, 2018, and 2019. We performed multivariate logistic regression analysis to compare the likelihood of prescribing antibiotic therapy versus no antibiotic therapy between the ED and ambulatory care settings.

RESULTS

We identified a weighted total of 3,041,193 HS patient visits. Approximately 49.0% of ambulatory visits resulted in antibiotic prescriptions. The most frequently prescribed antibiotics in the ambulatory setting were tetracyclines (41.2%), clindamycin (35.9%), and trimethoprim/sulfamethoxazole (21.6%). Approximately 74.7% of ED visits resulted in antibiotic prescriptions. The most frequently prescribed antibiotics in the ED setting were trimethoprim/sulfamethoxazole (44.5%), beta-lactams (33.2%), and clindamycin (27.7%). Multivariate logistic regression demonstrated significantly higher odds of receiving antibiotics in ED visits compared to ambulatory care visits. (OR 3.88; 95% Cl, 1.28-11.77; p = 0.02).

CONCLUSION

Antibiotic class selection varied significantly between the ED and ambulatory settings. Additionally, ED visits were more likely to result in antibiotic prescriptions than ambulatory visits for HS patients.

Conventional treatment of hidradenitis suppurativa: serving the "window of opportunity" concept

Hidradenitis suppurativa (HS) is a chronic, systemic, inflammatory skin disease characterized by inflammatory nodules, painful abscesses, and draining tunnels. It is associated with significant comorbidities, including inflammatory bowel disease, arthritis, pain, and a reduced quality of life. Unlike psoriasis or atopic dermatitis, it can progress from an inflammatory state to a nonreversible scaring component if not treated early enough and in an evidence-based manner. Until recently, adalimumab has been the only approved treatment for HS. Many conventional systemic treatments are currently used and have an appropriate role in HS therapy, provided they are used correctly in suitable patients. Unfortunately, many therapies, including antimicrobials, are used empirically, leading to continuous cycles of incorrect and inefficient treatment, disease progression, and reduced quality of life. Contributing to the problem is the delay in diagnosis which may be as long as seven years and insufficient or inappropriate intervention.. Capturing the "window of opportunity" is essential for a disease such as HS.

Medical Nutrition Therapy in Dermatological Diseases: A Joint Consensus Statement of the Italian Association of Dietetics and Clinical Nutrition (ADI), the Italian Society of Dermatology and Sexually Transmitted Diseases (SIDeMaST), the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut" and the Italian Society of Endocrinology (SIE), Club Nutrition, Hormones and Metabolism

Dermatological diseases such as acne, hidradenitis suppurativa (HS), and psoriasis are driven by chronic inflammation and oxidative stress. Emerging evidence highlights the role of nutrition in modulating these conditions, particularly through dietary patterns rich in antioxidants, polyphenols, and unsaturated fatty acids. RECENT FINDINGS: The Mediterranean diet (MedDiet) has demonstrated potential benefits due to its anti-inflammatory and immunomodulatory effects, while very low-energy ketogenic therapy (VLEKT) has shown promise in rapidly improving disease severity. Specific nutrients, including omega-3 fatty acids, probiotics, and micronutrients, may further contribute to disease management. However, the current literature is limited by small-scale studies and the lack of standardized dietary guidelines. PURPOSE OF REVIEW: This Consensus Statement, developed collaboratively by the Italian Association of Dietetics and Clinical Nutrition (ADI), the Italian Society of Dermatology and Sexually Transmitted Diseases (SIDeMaST), the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut" and the Italian Society of Endocrinology (SIE), Club Nutrition, Hormones and Metabolism, aimed to establish an evidence-based framework for medical nutrition therapy (MNT) of the most common inflammatory skin diseases, including acne, HS and psoriasis.

Pilot study of topical ruxolitinib demonstrates efficacy and blunting of heterogeneous inflammatory processes in mild hidradenitis suppurativa

BACKGROUND

Therapeutic options for mild hidradenitis suppurativa (HS) represent a significant gap in the current treatment landscape, with no U.S. Food and Drug Administration-approved therapies for early-stage HS. Topical Janus kinase (JAK) inhibitors (JAKi) are a compelling option due to the known upregulation of inflammatory JAK signalling in HS lesions and the recent success of systemic JAKi for the treatment of moderate-to-severe HS.

OBJECTIVES

To assess the clinical efficacy of ruxolitinib in a pilot cohort and to investigate the underlying biologic mechanisms associated with clinical response.

METHODS

This was a pilot single-site open-label prospective 24-week clinical trial of topical ruxolitinib (NCT04414514). Men and women with mild HS (Hurley stage I or II), with active inflammatory nodules, were recruited. All participants were observed for 8 weeks to monitor lesion counts (observational phase); active therapy (treatment phase) was then administered for 16 weeks. Topical ruxolitinib 1.5% cream was applied twice daily, covering the entirety of each HS-affected body site. Clinician- and patient-reported outcome measures were recorded throughout the study. Lesional skin punch biopsies were taken at the start and end of treatment for downstream mechanistic RNA sequencing and histological analyses.

RESULTS

Ten participants were enrolled in the study; four dropped out before the treatment phase of the trial. Six individuals with Hurley stage I (no tunnels) HS completed the study, five of whom successfully achieved Hidradenitis Suppurativa Clinical Response (HiSCR50) through 16 weeks of therapy. In this interim analysis, differential gene expression and gene set enrichment analyses revealed reduced activation of JAK-dependent interferon, interleukin (IL)-6, IL-2 and epidermal growth factor receptor signalling, and antimicrobial and keratinocyte responses. In contrast, signatures of wound healing and lipid metabolism were increased following JAKi treatment, indicating a return to homeostasis. Histological analyses revealed that clinically responsive patients had significantly reduced epidermal and dermal inflammation. Affected inflammatory infiltrate included neutrophils, T cells and plasma cells, with the predominantly affected cell types specific to the patient.

CONCLUSIONS

Collectively, the broad activity of topical ruxolitinib on inflammatory signalling processes resulted in promising efficacy, even with heterogeneity in baseline inflammation, in this pilot cohort. Importantly, topical treatment not only resolved epidermal inflammation, but also cleared deeper inflammatory infiltrate. The observed efficacy provides rationale to further investigate topical JAKi and other novel topical treatments in HS.

Hidradenitis Suppurativa: Pathogenesis and Inflammatory Pathways

The pathogenesis of hidradenitis suppurativa (HS) remains to be fully elucidated. Seminal clinical and translational investigations from the preceding 10 years have highlighted substantial variability in the contributors to inflammatory pathways involved in HS. These span from hormonal, metabolic, and microbial to genetic factors, each with potential flow on effects on immune cell polarization and subsequent clinically apparent inflammation. Understanding the heterogeneous drivers of HS and its progression may empower clinicians to take a more holistic approach in treatment planning, including addressing inflammatory comorbidities; therapeutic selection based on clinicopathological biomarkers; and appropriate patient counseling.

Managing Hidradenitis Suppurativa with Biologics and Small Molecule Inhibitors

"Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with a significant quality-of-life impact. In addition to the 2 drugs approved by the Food and Drug Administration for HS, adalimumab and secukinumab, several other biologic and small molecule inhibitors are used off-label or are in clinical trials. A systematic and evidence-based approach using these and other therapies-considering patient comorbidities, response to therapy, dose adjustment, and frequent troubleshooting-is required. In this article, we review the latest evidence supporting anti-inflammatory biologic and small molecule therapies for HS and provide a practical, algorithmic approach to management incorporating experience and expert opinion."

Neutrophil Extracellular Traps Are Widely Distributed Across Lesional and Perilesional Hidradenitis Suppurativa Skin, and Elevated Serum NET Markers Associate With Moderate to Severe HS Disease

BACKGROUND

Neutrophils are scarce in healthy skin but infiltrate lesions of hidradenitis suppurativa (HS) patients. Activated neutrophils release proinflammatory neutrophil extracellular traps (NETs), which have been implicated in the pathophysiology of HS. This study aimed to describe the distribution of NETs relative to the features of HS skin lesions and reveal whether serum NET markers were elevated in association with disease activity.

METHODS

Immunohistochemistry assessed the distribution of the key NET component citrullinated histone H3 (CitH3) in lesional, perilesional, and unaffected HS skin. Several markers of NETs (nucleosomes, calprotectin, and CitH3) were quantified in HS serum with ELISA.

RESULTS

HS lesional skin biopsies showed increased CitH3-positive staining compared to unaffected skin. This signal was widely distributed across both lesional and perilesional regions of HS skin and was associated with HS structures such as the lining of epithelialized skin tunnels. Moreover, several NET-associated markers were elevated in the serum of HS patients compared to healthy volunteers and correlated with each other. Finally, serum NET markers showed significant elevation in patients with moderate to severe disease activity based on IHS-4 scores, compared to those with no or mild activity.

CONCLUSIONS

Elevated NET markers are widely distributed in HS skin and serum. These data indicate that NET-associated markers in serum are candidate biomarkers for HS disease severity. The results confirm the rationale for anti-inflammatory therapy targeting NETs in HS.

Causal relationship and potential common pathogenic mechanisms between hidradenitis suppurativa and related cancer

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory and common skin disease. Observation studies have reported the association between HS and cancers, however no studies reported whether a causal relationship exists between HS and cancers. This study aimed to explore the causal relationship between HS and differential subtypes of cancers by conducting a bidirectional Mendelian randomization (MR) analysis.

METHOD

Genome-wide association study (GWAS) data related to HS and 16 subtypes of cancers were collected. The inverse variance weighted (IVW) method was primarily applied for our MR analysis, MR-Egger, weighted median, simple mode, and weighted mode methods were used additionally. Heterogeneity, horizontal pleiotropy, and potential outliers were assessed for the MR analysis results. Subsequently, disease-related genes were retrieved from the GeneCards database. To investigate the potential functions of these associated genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted.

RESULT

The results of our MR analysis indicated a causal association between HS and pancreatic cancer (PAC). Specifically, HS was found to elevate the risk of developing PAC (odds ratio (OR), 1.074; 95% confidence interval (CI) 1.015-1.135; p = 0.013). Conversely, reverse MR analysis demonstrated that PAC does not exert a causal effect on HS. Furthermore, our findings did not reveal any significant causal relationships between HS and other types of cancer. No evidence of heterogeneity or pleiotropy was identified in the analysis. Additionally, we identified disease-related genes, and subsequent GO and KEGG enrichment analyses indicated that the genes common to both HS and PAC are implicated in pathways associated with immune and inflammatory processes.

CONCLUSION

The results of this study offer novel evidence regarding the causal relationship between HA and PAC. Our Mendelian randomization analysis indicates that HS may have a causal influence on PAC, which could inform the development of improved treatment strategies for patients suffering from HS. However, the underlying mechanisms warrant further exploration.

Hepatocyte Growth Factor Has Unique Functions in Keratinocytes that Differ from those of IL-17A and TNF and May Contribute to Inflammatory Pathways in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that is difficult to control, and its mechanism remains unclear. Hepatocyte GF (HGF) has been reported to be significantly upregulated in the serum and skin of patients with HS, especially in the lesions with tunnels. In this study, we examined the transcriptome of HGF-treated keratinocytes and compared it with genetic profiling of HS lesions. HGF was highly expressed in HS skin, especially in the deep dermis, compared with that in healthy controls, and its source was mainly fibroblasts. HGF upregulated more genes in keratinocytes than IL-17A or TNF-a, and these genes included multiple epithelial-mesenchymal transition-related genes. Differentially expressed genes in HGF-stimulated keratinocytes were involved in activation of epithelial-mesenchymal transition-related pathways. These HGF-induced genes were significantly upregulated in HS lesions compared with those in healthy skin and nonlesions and were more strongly associated with HS tunnels. In summary, HGF was highly expressed in HS and induced epithelial-mesenchymal transition-related genes in keratinocytes; HGF-induced genes were highly associated with gene profiling of HS with tunnels, suggesting that HGF may be involved in HS tunnel formation through epithelial-mesenchymal transition.

Hidradenitis suppurativa, from basic science to surgery and a new era of tailored targeted therapy: An expert opinion paper

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterised by an aberrant activation of innate immunity and increased production of pro-inflammatory mediators such as interleukin 17 (IL-17). IL-17 has been shown to play a key role in the pathogenesis of HS and evidence highlights the potential of IL-17-targeted therapies. The fully human IgG/κ monoclonal antibody secukinumab, which specifically targets IL-17A and inhibits interaction with its receptor, has recently been approved for the treatment of moderate-to-severe HS. Secukinumab offers patients an efficacious and well-tolerated treatment option in terms of sustained response by rapidly improving signs and symptoms, and preventing disease progression in the absence of loss of response. Being a challenging disease, HS is associated with a delay to diagnosis of 3-10 years and, consequently, late implementation of appropriate treatment, leading to disease progression. Misdiagnosis due to flawed understanding and lack of awareness among medical providers and patients is considered an important factor contributing to the delayed diagnosis. Thus, serious efforts must be made on a large scale to urgently reduce the delay in HS diagnosis and reduce the disease burden in patients, including raising awareness, implementation of education programmes at medical and specialisation schools, as well as continuous education of healthcare providers at different levels for the early detection of HS and initiation of appropriate treatment. Here, we present the main critical unmet needs in the diagnosis and treatment of patients affected by HS, address how disease awareness and comprehensive multidisciplinary management (offering both medical and surgical care) can benefit patients, and suggest therapeutic options, based on clinical characterisation and early identification and intervention (window of opportunity), to be adopted for a timely and better management of disease progression and to fill current gaps.

The Inflammatory Landscape of a Whole-Tissue Explant Model of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a relatively common and highly morbid inflammatory skin disease. Due to the relatively limited understanding of HS's pathogenesis, there are currently insufficient treatment options available, and many patients' medical needs are not being met. This is partly due to the historical scarcity of ex vivo assays and animal models that accurately recapitulate the disease. Thus, we have developed a standardised whole-tissue explant model of HS to examine its pathogenic mechanisms and the efficacy of potential treatments within intact human tissue. We measured cytokine protein and RNA within whole tissue maintained in an agar-media solution, finding that IL-6 and IL-8 concentrations trended upwards in both HS explants and healthy controls, while IL-17A, IL-1β, and TNF-α exhibited increases in HS tissue alone. We also show that the explants were responsive to treatment with both dexamethasone and IL-2. Not only do our results show that this model effectively delivers treatments throughout the explants, but they also elucidate which cytokines are related to the explant process regardless of tissue state and which are related to HS tissue specifically, laying the groundwork for future implementations of this model.

Polygenic Score: A Tool for Evaluating the Genetic Background of Sporadic Hidradenitis Suppurativa

Sporadic hidradenitis suppurativa (spHS) is a multifactorial disease in which genetic predisposition is intertwined with environmental factors. Owing to the still-to-date limited knowledge of spHS genetics, we calculated polygenic scores (PGSs) to study the genetic underpinnings that contribute to spHS within European demographic. A total of 256 patients with spHS and 1686 healthy controls were analyzed across 6 European clinical centers. PGSs were calculated using a clumping and thresholding technique on 70% of the total sample, with the remaining 30% used for testing. The PANTHER tool was used to identify overrepresented genes. We generated a PGS characterized by 923 SNPs with a statistically significant association with spHS (P = 2 × 10-2). The statistically significant age-, sex-, and ancestry-adjusted association of our developed PGSs in spHS allows us to attribute a genetic contribution to the susceptibility of spHS (pseudo-R2 = 0.0053). Variants enriched for developing PGSs show a statistically significant preference for mapping to genes that encode primarily for cell adhesion proteins. Although this study developed a polygenic model associated with spHS, the low number of patients enrolled is a limitation. However, we believe that with larger experimental datasets, our model has the potential to serve as a valuable tool for predicting spHS states in future studies.

A Novel Whole Tissue Explant Model of Hidradenitis Suppurativa

Hidradenitis Suppurativa (HS) is a relatively common and highly morbid inflammatory skin disease. Due to our relatively limited understanding of HS's pathogenesis, there are currently insufficient treatment options available, and many patients' medical needs are not being met. This is partly due to a scarcity of ex vivo human assays and animal models that accurately recapitulate the disease. To address this deficit, we have developed a whole-tissue explant model of HS to examine its pathogenic mechanisms and the efficacy of potential treatments within intact human tissue. We measured cytokine protein and RNA within whole tissue maintained in an agar-media solution, finding that IL-6 and IL-8 concentrations trended upwards in both HS explants and healthy controls, while IL-17A, IL-1β, and TNF-α exhibited increases in HS tissue alone. We also show that the explants were responsive to treatment with both dexamethasone and IL-2. Not only do our results show that this model effectively delivers treatments throughout the explants, but they also elucidate which cytokines are related to the explant process regardless of tissue state and which are related to HS tissue specifically, laying the groundwork for future implementations of this model.

Approach to the Atypical Wound

The heterogeneity of atypical wounds can present diagnostic and therapeutic challenges; however, as the prevalence of atypical wounds grows worldwide, prompt and accurate management is increasingly an essential skill for dermatologists. Addressing the underlying cause of an atypical wound is critical for successful outcomes. An integrated approach with a focus on pain management and patient engagement is recommended to facilitate enduring wound closure. Advances in treatment, in addition to further research and clinical training, are necessary to address the expanding burden of atypical wounds.

Genetic factors associated with hidradenitis suppurativa, a literature review

Background

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by deep-seated, painful lesions most frequently occurring in intertriginous areas of the skin. HS leads to poor quality of life in affected individuals and is difficult to diagnose and treat.

Objective

Understanding the genetics associated with familial inheritance may lead to a better understanding of the pathogenesis of this debilitating disease.

Methods

Articles published until March 9, 2023, were identified in PubMed using the following search terms: hidradenitis suppurativa and gene* or acne inversa and gene*.

Results

The rate of monogenic mutations associated with HS is less than 7%, with the most common genetic mutations reported in sporadic and familial HS cases being in NCSTN and less frequently in PSENEN. Individuals with mutations in the gamma-secretase complex tended to have more severe HS and an early age of onset.

Limitations

This study was limited to the case studies available in PubMed, the majority of which used targeted gene panels to detect genetic mutations.

Conclusion

Approximately 30% of individuals diagnosed with HS report having a positive family history; however, very few studies demonstrate monogenic familial transmission of HS. The case studies of syndromic HS reported a variety of genetic mutations associated with HS, some of which were familial, while others were sporadic, suggesting that other pathways may be involved in the pathogenesis of HS and other potential mutations that have yet to be evaluated. More research is needed to understand the genetic mutations in HS.

Biologics for Hidradenitis suppurativa: evolution of the treatment paradigm

INTRODUCTION

Hidradenitis suppurativa (HS) is an autoinflammatory skin disease with a high unmet need for effective medical management. Clinically, it is characterized by inflammatory nodules that may progress into abscesses, draining tunnels and extensive scarring, mainly affecting apocrine gland-bearing areas.

AREAS COVERED

Treatment options include topical and systemic medications and a variety of surgical procedures. The anti-TNF-α antibody adalimumab and the anti-IL-17 secukinumab are the only two approved biologics for HS, showing moderate efficacy. HS research is a rapidly growing field, with a wide range of agents leveraging distinct mechanisms of action currently under development. Drugs targeting the IL-17 and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are the most advanced in both ongoing and completed Phase 3 studies, promising deeper levels of response. Use of other, off-label biologics is also discussed.

EXPERT OPINION

A therapeutic algorithm is proposed based on comorbidities and existing evidence. Patient-tailored combinations between biologics and other biologics or small molecules will hopefully allow clinicians to target most events in HS pathophysiology in a complementary way while obtaining a meaningful effect on their devastating manifestations.

Alterations to the Hidradenitis Suppurativa Serum Proteome with Spleen Tyrosine Kinase Antagonism: Proteomic Results from a Phase 2 Clinical Trial

Hidradenitis suppurativa is a disease in great need of novel therapies. Given the heterogeneous nature of the disease and the variable response to therapies, biomarkers are essential to predict response to therapies and increase our understanding of disease pathogenesis. Our recent phase 2 clinical trial of spleen tyrosine kinase antagonism using fostamatinib in hidradenitis suppurativa demonstrated a 75% clinical response, with the greatest benefit in individuals with elevated serum inflammation and IgG. In this study, we present results of an in-depth serum proteomic analysis in this patient cohort identifying downregulation of IL-12B as well as B-cell-associated proteins CCL19 and CCL20 and IFN-γ-mediated proteins CXCL10 and CX3CL1. Clinical responders demonstrated greater reduction in serum IL-17A, IL-6, IL-8, and CX3CL1 compared with clinical nonresponders. Baseline levels of CCL28 were associated with clinical response to fostamatinib therapy at week 12. Overall, this suggests that fostamatinib, by targeting B-cell receptor and Fc receptor activity in B cells, monocytes, and macrophages, has a significant molecular impact on the inflammatory serum proteome of hidradenitis suppurativa. In addition, potential therapeutic biomarkers may aid in patient selection for targeted therapy.

Rethinking Hidradenitis Suppurativa Management: Insights into Bacterial Interactions and Treatment Evolution

Hidradenitis suppurativa (HS), or acne inversa, is a chronic inflammatory dermatological condition characterized by painful and recurrent nodules and purulent abscesses. HS can have a devastating impact on the quality of life of patients. This condition is commonly localized to the axilla, groin, perineal, and inframammary regions, and can develop fistulas and sinus tracts over time. Its pathogenesis remains elusive and is best characterized at the moment as multi-factorial. Additionally, questions remain about the role of cutaneous dysbiosis as a primary HS trigger or as a secondary perturbation due to HS inflammation. This article features works in relation to HS and its interplay with bacterial microflora. We address current treatment approaches and their impact on HS-related bacteria, as well as areas of therapeutic innovation. In the future, disease-modifying or remittive therapy will likely combine an advanced/targeted anti-inflammatory approach with one that effectively modulates cutaneous and deep tissue dysbiosis.

Efficacy and safety of the oral Janus kinase 1 inhibitor povorcitinib (INCB054707) in patients with hidradenitis suppurativa in a phase 2, randomized, double-blind, dose-ranging, placebo-controlled study

BACKGROUND

Janus kinase 1 inhibition may alleviate hidradenitis suppurativa (HS)-associated inflammation and improve symptoms.

OBJECTIVE

To assess efficacy and safety of povorcitinib (selective oral Janus kinase 1 inhibitor) in HS.

METHODS

This placebo-controlled phase 2 study randomized patients with HS 1:1:1:1 to receive povorcitinib 15, 45, or 75 mg or placebo for 16 weeks. Primary and key secondary end points were mean change from baseline in abscess and inflammatory nodule count and percentage of patients achieving HS Clinical Response at week 16.

RESULTS

Of 209 patients randomized (15 mg, n = 52; 45 mg, n = 52; 75 mg, n = 53; placebo, n = 52), 83.3% completed the 16-week treatment. At week 16, povorcitinib significantly reduced abscess and inflammatory nodule count from baseline (least squares mean [SE] change: 15 mg, -5.2 [0.9], P = .0277; 45 mg, -6.9 [0.9], P = .0006; 75 mg, -6.3 [0.9], P = .0021) versus placebo (-2.5 [0.9]). More povorcitinib-treated patients achieved HS Clinical Response at week 16 (15 mg, 48.1%, P = .0445; 45 mg, 44.2%, P = .0998; 75 mg, 45.3%, P = .0829) versus placebo (28.8%). A total of 60.0% and 65.4% of povorcitinib- and placebo-treated patients had adverse events.

LIMITATIONS

Baseline lesion counts were mildly imbalanced between groups.

CONCLUSION

Povorcitinib demonstrated efficacy in HS, with no evidence of increased incidence of adverse events among doses.

[Hidradenitis suppurativa]

Hidradenitis suppurativa (HS) is a chronic and debilitating inflammatory disease derived from the pilosebaceous unit, that affects approximately 1% of the general population. Clinically, it is characterized by inflammatory nodules, abscesses, and tunnels in the intertriginous areas of the body, especially in the axillary, inguinal, and anogenital regions. The etiopathogenesis of HS is not completely understood, although it is considered to be multifactorial, and the result of a complex interaction between genetic, hormonal, environmental, and immunological factors. In this sense, several proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-L-1β, and IL-17, among others, appear to play a crucial role in the pathogenesis of the disease. Currently, HS is recognized as a systemic disease associated with numerous comorbidities, including cardiovascular, immune-mediated, and endocrine-metabolic diseases. The treatment of HS must be carried out with an individualized and patient-oriented approach, considering medical and surgical treatment modalities.

Secukinumab in Hidradenitis Suppurativa Patients Who Failed Adalimumab: A 52-Week Real-Life Study

Background

The treatment of hidradenitis suppurativa (HS) has always been a real challenge for dermatologists; to date, adalimumab the only biologic drug approved for HS is adalimumab, an anti-tumor necrosis factor (TNF)-α drug, the approval of this drug dates to 2015, data provided by real life show an effectiveness rate of about 60% percent. Recently (31 October 2023) FDA approves secukinumab for moderate-severe HS. The treatment and management of HS is very challenging as available treatments are very limited and show very variable outcomes.

Methods

We conducted a prospective monocentric study designed to evaluate the efficacy and safety of secukinumab treatment in HS patients in a real-life setting.

Results

The initial cohort of patients recruited included 21 HS patients including 12 females and 9 males. About 57.1% of patients achieved the primary endpoint and recorded significant decrease in all the severity assessment scales (IHS4, DLQI and VAS pain scale) at week 16 and 52, when HiSCR reached 71.4%.

Conclusion

The results of our study highlight that treatment with secukinumab in patients with severe HS who failed adalimumab may be a safe and effective therapeutic weapon.

The Cystic Sponge Anus

Introduction

A peculiar spongy appearance of the perianal skin was observed in a patient who underwent wide excision surgery for inguinal and gluteal hidradenitis suppurativa (HS).

Case Presentation

This peculiar appearance was observed in a 62-year-old male patient. It included multiple orifices and cavities forming the spongy aspect of the perianal skin with multiple cysts and giant comedones. The perianal lesions were asymptomatic and the patient had never received any perianal treatment for the comedones or cysts. Histopathology was performed and demonstrated dilated hair follicles with flaky keratin and loose hair shafts in the center. The spongy appearance was most likely the result of spontaneous shedding of the cystic contents.

Conclusion

We suspect that the "cystic sponge anus" might be associated with HS, smoking, the male gender, and may yet be another expression of an occlusive follicular disease. Future studies will be needed to clarify the prevalence and comorbidities of the "cystic sponge anus."

NK and NKT cells in the pathogenesis of Hidradenitis suppurativa: Novel therapeutic strategy through targeting of CD2

Hidradenitis suppurativa (HS) is a chronic debilitating inflammatory skin disease with poorly understood pathogenesis. Single-cell RNAseq analysis of HS lesional and healthy individual skins revealed that NKT and NK cell populations were greatly expanded in HS, and they expressed elevated CD2, an activation receptor. Immunohistochemistry analyses confirmed significantly expanded numbers of CD2+ cells distributed throughout HS lesional tissue, and many co-expressed the NK marker, CD56. While CD4+ T cells were expanded in HS, CD8 T cells were rare. CD20+ B cells in HS were localized within tertiary follicle like structures. Immunofluorescence microscopy showed that NK cells (CD2 + CD56 dim ) expressing perforin, granzymes A and B were enriched within the hyperplastic follicular epidermis and tunnels of HS and juxtaposed with apoptotic cells. In contrast, NKT cells (CD2 + CD3 + CD56 bright ) primarily expressed granzyme A and were associated with α-SMA expressing fibroblasts within the fibrotic regions of the hypodermis. Keratinocytes and fibroblasts expressed high levels of CD58 (CD2 ligand) and they interacted with CD2 expressing NKT and NK cells. The NKT/NK maturation and activating cytokines, IL-12, IL-15 and IL-18, were significantly elevated in HS. Inhibition of cognate CD2-CD58 interaction with blocking anti-CD2 mAb in HS skin organotypic cultures resulted in a profound reduction of the inflammatory gene signature and secretion of inflammatory cytokines and chemokines in the culture supernate. In summary, we show that a cellular network of heterogenous NKT and NK cell populations drives inflammation, tunnel formation and fibrosis in the pathogenesis of HS. Furthermore, CD2 blockade is a viable immunotherapeutic approach for the management of HS.

Has the time come to assess small-molecule/biologic drug combinations for the management of moderate-to-severe hidradenitis suppurativa?

As the landscape for hidradenitis suppurativa (HS) medical treatment is rapidly expanding, seemingly taking the same steps that marked the evolution of psoriasis management, upcoming agents still do not appear to offer complete disease control. Better control of severe cases of HS refractory to biologic monotherapy may require investigation of pathogenesis-driven, combination regimens sooner rather than later.

A late presentation of inguinoscrotal cutaneous squamous cell carcinoma (cSCC) masquerading as hidradenitis suppurativa-a case report

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that affects apocrine gland-bearing skin in intertriginous areas; it is characterized by persistent or recurrent abscesses that culminate in a purulent discharge, sinuses and scarring. Although it is a common condition, it is rarely associated with cutaneous squamous cell carcinoma (cSCC). Whereas the female-to-male ratio of HS is 3:1, SCC in HS has a female-to-male ratio of 1:5. In this study, we present a 50-year-old male patient with a late presentation of inguinoscrotal cSCC with extensive ulceration and erythema that was hidden by neglected HS and the presence of underlying human papillomavirus in the affected area. The histomorphologic and immunohistochemical findings support the diagnosis of cSCC. Timely detection is the key to improve prognosis, regular clinical examination and biopsy of any suspicious lesions in high-risk patients is highly recommended.

Dysregulated CD38 expression in blood and skin immune cells of patients with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a multifactorial, inflammatory skin disease. Increased systemic inflammatory comorbidities and serum cytokines highlight systemic inflammation as a feature of HS. However, the specific immune cell subsets contributing to systemic and cutaneous inflammation have not been resolved. Here, we generated whole-blood immunomes by mass cytometry. We performed a meta-analysis of RNA-seq data, immunohistochemistry, and imaging mass cytometry to characterize the immunological landscape of skin lesions and perilesions from patients with HS. Blood from patients with HS exhibited lower frequencies of natural killer cells, dendritic cells, and classical (CD14+CD16-) and nonclassical (CD14-CD16+) monocytes, as well as higher frequencies of Th17 cells and intermediate (CD14+CD16+) monocytes than blood from healthy controls. Classical and intermediate monocytes from patients with HS had increased expression of skin-homing chemokine receptors. Furthermore, we identified a CD38+ intermediate monocyte subpopulation that was more abundant in the immunome of blood from patients with HS. Meta-analysis of RNA-seq data found higher CD38 expression in lesional HS skin than in perilesional skin, and markers of classical monocyte infiltration. Imaging mass cytometry showed that CD38+ classical monocytes and CD38+ monocyte-derived macrophages were more abundant in lesional HS skin. Overall, we report targeting CD38 may be worth pursuing in clinical trials.

Adipokines as an important link between hidradenitis suppurativa and obesity: a narrative review

Hidradenitis suppurativa (HS) is a chronic, recurrent, debilitating disorder of the pilosebaceous unit. Although its pathophysiology is not fully explained, inflammation seems to play an essential role in the development of HS. A link between obesity - often considered a state of chronic inflammation - and a higher prevalence of HS has been described. Nevertheless, the exact association is not well understood. Adipose tissue is a highly active endocrine organ that produces and secretes a variety of metabolically and immunologically active molecules called adipokines. The imbalances in concentrations of several adipokines in patients with HS have already been described. A shift towards the overproduction of proinflammatory adipokines (including leptin, resistin and visfatin) with the suppression of anti-inflammatory ones (adiponectin) has been noted. We conducted a review of the available data on adipokines in HS, concentrating on the described imbalances in adipokine concentrations, as well as possible implications in HS pathogenesis. Moreover, new, unstudied adipokines with possible implications in the development of HS are proposed.

Tertiary Lymphoid Structures Sustain Cutaneous B cell Activity in Hidradenitis Suppurativa

Background

Hidradenitis suppurativa (HS) skin lesions are highly inflammatory and characterized by a large immune infiltrate. While B cells and plasma cells comprise a major component of this immune milieu the biology and contribution of these cells in HS pathogenesis is unclear.

Objective

We aimed to investigate the dynamics and microenvironmental interactions of B cells within cutaneous HS lesions.

Methods

We combined histological analysis, single-cell RNA-sequencing (scRNAseq), and spatial transcriptomic profiling of HS lesions to define the tissue microenvironment relative to B cell activity within this disease.

Results

Our findings identify tertiary lymphoid structures (TLS) within HS lesions and describe organized interactions between T cells, B cells, antigen presenting cells and skin stroma. We find evidence that B cells within HS TLS actively undergo maturation, including participation in germinal center reactions and class switch recombination. Moreover, skin stroma and accumulating T cells are primed to support the formation of TLS and facilitate B cell recruitment during HS.

Conclusion

Our data definitively demonstrate the presence of TLS in lesional HS skin and point to ongoing cutaneous B cell maturation through class switch recombination and affinity maturation during disease progression in this inflamed non-lymphoid tissue.

Development and validation of IHS4-55, an IHS4 dichotomous outcome to assess treatment effect for hidradenitis suppurativa

BACKGROUND

Validated, inclusive and easy-to-use outcomes for hidradenitis suppurativa are essential both in the clinical trial setting and clinical practice. The continuous IHS4 is a validated tool that dynamically assesses nodules/abscesses/draining tunnels and classifies disease severity as mild/moderate/severe. However, dichotomous outcomes are often required for clinical trials reporting.

OBJECTIVE

To develop and validate a dichotomous outcome based on IHS4 that can be used in clinical trial settings and day-to-day clinical practice.

METHODS

De-identified data from the PIONEER-I and -II studies were accessed through Vivli. Potential IHS4 thresholds were analysed using baseline to Week 12 data from adalimumab- and placebo-treated hidradenitis suppurativa patients in the PIONEER-I trial. The final threshold was chosen based on its ability to discriminate between patients treated with adalimumab or placebo and its association with reduction in inflammatory lesions. The final threshold was validated using data from baseline to Week 12 from adalimumab- and placebo-treated hidradenitis suppurativa patients in both the PIONEER-II and the combined PIONEER-I and -II studies.

RESULTS

The best performing cut-off for the IHS4 was a 55% reduction of the IHS4 score (IHS4-55). Patients who achieved the IHS4-55 had an odd's ratio of 2.00 [95%-CI 1.26-3.18, p = 0.003], 2.79 (95%-CI 1.76-4.43, p < 0.001) and 2.16 (95%-CI 1.43-3.29, p < 0.001) for being treated with adalimumab rather than placebo in PIONEER-I, PIONEER-II and the combined dataset, respectively. Additionally, the achievement of the IHS4-55 was associated with a significant reduction in inflammatory nodules, abscesses and draining tunnels in all analysed datasets.

CONCLUSIONS

IHS4-55, a novel dichotomous IHS4 version, based on a 55% reduction of the total score was developed. The IHS4-55 performs similarly to the HiSCR in discriminating between adalimumab- and placebo-treated hidradenitis suppurativa patients and shows significant associations with reductions in lesion counts. Moreover, the IHS4-55 addresses some of the HiSCR drawbacks by dynamically including draining tunnels in a validated manner. By allowing the analysis of hidradenitis suppurativa patients with an abscess and nodule count below 3 but many draining tunnels, this outcome measure will improve inclusivity in clinical trials.

Dysregulated CD38 expression in blood and skin immune cells of patients with hidradenitis suppurativa

Background

Hidradenitis suppurativa (HS) is a multifactorial, inflammatory skin disease. Increased systemic inflammatory comorbidities and serum cytokines highlight systemic inflammation as a feature of HS. However, the specific immune cell subsets contributing to systemic and cutaneous inflammation have not been resolved.

Objective

Identify features of peripheral and cutaneous immune dysregulation.

Methods

Here, we generated whole-blood immunomes by mass cytometry. We performed a meta-analysis of RNA-seq data, immunohistochemistry, and imaging mass cytometry to characterize the immunological landscape of skin lesions and perilesions from patients with HS.

Results

Blood from patients with HS exhibited lower frequencies of natural killer cells, dendritic cells, and classical (CD14+CD16-) and nonclassical (CD14-CD16+) monocytes, as well as higher frequencies of Th17 cells and intermediate (CD14+CD16+) monocytes than blood from healthy controls. Classical and intermediate monocytes from patients with HS had increased expression of skin-homing chemokine receptors. Furthermore, we identified a CD38+ intermediate monocyte subpopulation that was more abundant in the immunome of blood from patients with HS. Meta-analysis of RNA-seq data found higher CD38 expression in lesional HS skin than in perilesional skin, and markers of classical monocyte infiltration. Imaging mass cytometry showed that CD38+ classical monocytes and CD38+ monocyte-derived macrophages were more abundant in lesional HS skin.

Conclusion

Overall, we report targeting CD38 may be worth pursuing in clinical trials.

Key Messages

3.Monocyte subsets express markers of activation in circulation and HS lesionsTargeting CD38 may be a viable strategy for treating systemic and cutaneous inflammation in patients with HS.

Capsule Summary

4.Dysregulated immune cells in patients with HS express CD38 and may be targeting by anti-CD38 immunotherapy.

The Hidradenitis Suppurativa 'Omics Database (HS-OmicsDB)

Large scale meta-analyses of genomics and genetics have spurred research in a number of fields, such as cancer, genetics and immunology. Publicly available 'omics databases provide valuable hypothesis generating and validation tools. To date, no such initiative has been undertaken for Hidradenitis Suppurativa (HS), an inflammatory skin disease of unknown etiology. We present here, a longitudinal initiative seeking to aggregate publicly available 'omics data to enhance research efforts in HS. In its first iteration, we include bulk and single-cell RNA sequencing data from untreated HS patients. Our data, aggregated from publicly available GEO datasets provides a tool to profile gene expression in specific tissue types (i.e. lesional, perilesional, nonlesional and healthy skin) as well as map cell-specific gene expression on single-cell data from HS lesions.

Complement activation in Hidradenitis suppurativa: Covert low-grade inflammation or innocent bystander?

Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin disease with a complex and multifactorial pathogenesis involving both the innate and adaptive immune system. Despite limited evidence for local complement activation, conflicting results have been published on the role of systemic complement activation in HS. It was hypothesized that complement was consumed in highly inflamed HS skin, trapping complement from the circulation. Therefore, the aim of this study was to evaluate this local complement deposition in HS skin lesions using routine and commonly used complement antibodies.Direct immunofluorescence for C1q, C3c, C4d, C5b-9, and properdin was performed on frozen tissue sections of 19 HS patients and 6 controls. C5a receptor 1 (C5aR1) was visualized using immunohistochemistry.

Overall, we found no significant local complement deposition in HS patients versus controls regarding C1q, C3c, C4d, C5b-9, or properdin on either vessels or immune cells. C5aR1 expression was exclusively found on immune cells, predominantly neutrophilic granulocytes, but not significantly different relatively to the total infiltrate in HS lesions compared with controls. In conclusion, despite not being able to confirm local complement depositions of C1q, C3c, C4d, or properdin using highly sensitive and widely accepted techniques, the increased presence of C5aR1 positive immune cells in HS suggests the importance of complement in the pathogenesis of HS and supports emerging therapies targeting this pathway.

Recent advances in hidradenitis suppurativa: Role of race, genetics, and immunology

Hidradenitis suppurativa (HS) is a multifactorial chronic skin disease characterized by inflammation around the hair follicles commonly affecting intertriginous areas. The underlying pathogenesis of HS and its molecular mechanisms are largely understudied. Genetic studies in families have identified variants within the γ-secretase complex associated with HS; however, no definitive genotype-phenotype correlations have been made. The lack of knowledge regarding the intersection of genetics, immunology and environmental risk factors is a major obstacle to improving treatment for patients with HS. This article provides an overview of the role of race, genetics, and immunology in HS to provide insight into the multiple factors influencing the pathophysiology of HS.