Hidradenitis suppurativa

Belgian Patients of the European Registry for Hidradenitis Suppurativa (ERHS-Be): Data, Scores, and Phenotypes since 2015

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease, characterized by painful and recurrent lesions in apocrine gland-bearing skin areas. It is a heterogeneous disease, which makes assessment and data collection difficult. Questionnaires with detailed items, such as the Belgian European Registry for Hidradenitis Suppurativa (ERHS-Be), are useful to study HS and its associated comorbidities. The aim of this registry was to uncover new factors associated with HS and understand HS patients' clinical profiles and efficacy of treatments.

MATERIAL AND METHODS

The ERHS-Be registry is based on questionnaires, with sections for sociodemographic data, medical and HS history, clinical examination, and treatment plan. It allows identification of different clinical phenotypes and automatic calculation of severity scores.

RESULTS

At present, 606 patients are included in the ERHS-Be (67% women, 33% men). The mean age at the first visit is 38.5 years. Tobacco use is present in 72.6% of patients. A family history of HS is noted in 42% of patients. Comorbidities are documented in this cohort: depression is present in 43.8% of patients, arthritis in 27.8%, obesity in 31.5%, hypertension in 10.6%, diabetes mellitus in 6.4%, and dyslipidemia in 12.4%. Moreover, 7.7% of patients suffer from IBD and 27.4% have a pilonidal sinus. History of severe acne is found in 32.1% of patients and psoriasis in 9.3%. Thirteen percent of women in our cohort suffer from polycystic ovarian syndrome. Severity of disease is quantified in 533 patients: for instance, Hurley I, II, and III scores proportions are, respectively, 32.3%, 52.7%, and 15%, while the mean IHS4 score is 5.2. This registry also enables determination of relative phenotype proportions in our cohort, according to different classifications.

CONCLUSION

The ERHS-Be questionnaires allow systematic and larger data collection, including detailed comorbidities, phenotypes, and severity of disease. Analysis of this large database will contribute to a better understanding and management of HS, at a time where new therapeutic options are becoming available.

Biosensing circulating MicroRNAs in autoinflammatory skin diseases: Focus on Hidradenitis suppurativa

MicroRNAs (miRNAs) play a crucial role in the early diagnosis of autoinflammatory diseases, with Hidradenitis Suppurativa (HS) being a notable example. HS, an autoinflammatory skin disease affecting the pilosebaceous unit, profoundly impacts patients' quality of life. Its hidden nature, with insidious initial symptoms and patient reluctance to seek medical consultation, often leads to a diagnostic delay of up to 7 years. Recognizing the urgency for early diagnostic tools, recent research identified significant differences in circulating miRNA expression, including miR-24-1-5p, miR-146a-5p, miR26a-5p, miR-206, miR338-3p, and miR-338-5p, between HS patients and healthy controls. These miRNAs serve as potential biomarkers for earlier disease detection. Traditional molecular biology techniques, like reverse transcription quantitative-polymerase chain reaction (RT-qPCR), are employed for their detection using specific primers and probes. Alternatively, short peptides offer a versatile and effective means for capturing miRNAs, providing specificity, ease of synthesis, stability, and multiplexing potential. In this context, we present a computational simulation pipeline designed for crafting peptide sequences that can capture circulating miRNAs in the blood of patients with autoinflammatory skin diseases, including HS. This innovative approach aims to expedite early diagnosis and enhance therapeutic follow-up, addressing the critical need for timely intervention in HS and similar conditions.

An evaluation of secukinumab for the treatment of moderate-to-severe hidradenitis suppurativa

INTRODUCTION

Until recently, biological therapy for hidradenitis suppurativa was limited to anti-tumor necrosis factor (TNF) blockade with adalimumab (ADA). However, not all patients respond to treatment with ADA. This highlighted the need for more therapeutic options. Interleukin (IL)-17/T-helper 17 (Th17) axis may play an important role in the pathophysiology of HS. Recently, the IL-17A inhibitor secukinumab, which targets IL-17A specifically and prevents it from interacting with the IL-17 receptor, has been FDA-approved for HS.

AREAS COVERED

Secukinumab, represents a novel therapeutic strategy in HS management. An overview of structural and pharmacological characteristics is provided. Described efficacy in clinical trials and case reports and safety data from is presented.

EXPERT OPINION

As response to anti-TNFas is lost over time, secukinumab has provided an alternative HS treatment option in clinical practice. Overall, secukinumab has shown good efficacy and a favorable side effect profile in HS clinical trials but may be avoided in patients with inflammatory bowel disease. Long-term and real-life data on the use of secukinumab are essential for improving decision-making in HS therapy.

The NLRP3 Inflammasome Gene Is Overexpressed in Hidradenitis Suppurativa Lesions: A Preliminary Study on the Role of Pyroptosis in Disease Pathogenesis

Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disorder, and its pathogenesis remains incompletely understood. This study aimed to investigate the role of the P2X7 receptor (P2X7R) and NLRP3 inflammasome in HS pathogenesis. RNA sequencing and real-time PCR were performed to assess the gene expression levels of P2X7R and NLRP3 in the skin biopsies of HS patients and healthy controls (HC). The results of our study revealed a significantly increased expression of the NLRP3 gene in both the lesional and perilesional skin of HS patients compared to healthy controls. Moreover, the mRNA levels of NLRP3 were significantly higher in lesional skin compared to non-lesional skin in HS patients, indicating the spread of inflammation to adjacent tissues. In contrast, no significant differences in P2X7R gene expression were observed between the three groups. These findings suggest the involvement of NLRP3 inflammasomes in HS pathogenesis, while P2X7R may not play a significant role in the disease. This research sheds light on the complex inflammatory pathways in HS, highlighting the potential of NLRP3 as a therapeutic target. Understanding the molecular mechanisms underlying HS is crucial for the development of targeted treatment modalities for this debilitating condition.

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.

Liraglutide for the treatment of obesity among patients with hidradenitis suppurativa

BACKGROUND AND AIMS

Hidradenitis suppurativa (HS) is associated with obesity. Weight loss is frequently reflected in an amelioration in the severity of the lesions. Case reports have suggested that liraglutide might improve not only weight but also skin. We aimed to study the effects of liraglutide 3mg in patients with obesity and HS on metabolic and dermatological parameters.

METHODS

14 patients started treatment with liraglutide for 3 months. Severity of the lesions was evaluated using the Hurley Staging System and quality of life with the DLQI (Dermatology Quality Index).

RESULTS

There was a significant reduction in BMI (39.3±6.2 vs 35.6±5.8; p=0.002), waist circumference (121.3±19.2 vs 110.6±18.1cm; p=0.01), CRP (4.5±2.2 vs 3±2.1mg/L; p=0.04), homocysteine (16.2±2.9 vs 13.3±3μmol/L; p=0.005) and plasma cortisol (15.9±4.8 vs 12.6±4.5μg/dL; p=0.007). Hurley (2.6±0.5 vs 1.1±0.3; p=0.002) and DLQI (12.3±2.8 vs 9.7±6.9; p=0.04) improved significantly. In multiple regression analysis, weight loss did not correlate with any inflammatory parameter or Hurley.

CONCLUSIONS

Liraglutide 3mg is effective and safe among patients with HS and obesity. Long-term studies are mandatory to assess the effects of liraglutide on skin lesions and inflammatory markers among subjects with HS beyond weight loss.

Harnessing artificial intelligence for advancing early diagnosis in hidradenitis suppurativa

This perspective delves into the integration of artificial intelligence (AI) to enhance early diagnosis in hidradenitis suppurativa (HS). Despite significantly impacting Quality of Life, HS presents diagnostic challenges leading to treatment delays. We present a viewpoint on AI-powered clinical decision support system designed for HS, emphasizing the transformative potential of AI in dermatology. HS diagnosis, primarily reliant on clinical evaluation and visual inspection, often results in late-stage identification with substantial tissue damage. The incorporation of AI, utilizing machine learning and deep learning algorithms, addresses this challenge by excelling in image analysis. AI adeptly recognizes subtle patterns in skin lesions, providing objective and standardized analyses to mitigate subjectivity in traditional diagnostic approaches. The AI integration encompasses diverse datasets, including clinical records, images, biochemical and immunological data and OMICs data. AI algorithms enable nuanced comprehension, allowing for precise and customized diagnoses. We underscore AI's potential for continuous learning and adaptation, refining recommendations based on evolving data. Challenges in AI integration, such as data privacy, algorithm bias, and interpretability, are addressed, emphasizing the ethical considerations of responsible AI deployment, including transparency, human oversight, and striking a balance between automation and human intervention. From the dermatologists' standpoint, we illustrate how AI enhances diagnostic accuracy, treatment planning, and long-term follow-up in HS management. Dermatologists leverage AI to analyze clinical records, dermatological images, and various data types, facilitating a proactive and personalized approach. AI's dynamic nature supports continuous learning, refining diagnostic and treatment strategies, ultimately reshaping standards of care in dermatology.

Genetic mutations in pyoderma gangrenosum, hidradenitis suppurativa, and associated autoinflammatory syndromes: Insights into pathogenic mechanisms and shared pathways

Pyoderma gangrenosum (PG), hidradenitis suppurativa (HS), and the associated autoinflammatory syndromes, including pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome, PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH) syndrome, and pyogenic arthritis, pyoderma gangrenosum, acne, and suppurative hidradenitis (PAPASH) syndrome are dermatological conditions characterized by chronic inflammation and tissue damage. Recent advances in genetic research have identified specific mutations associated with these disorders, shedding light on their underlying pathogenic mechanisms. This review aims to summarize the current knowledge of identified mutations and presumed pathophysiology in PG, HS, and the associated autoinflammatory syndromes.

Eco-friendly micellar HPLC approach for simultaneous estimation of combination therapy for hidradenitis suppurativa: Applications to spiked human plasma and different dosage forms

This study introduces a new method for analyzing rifampicin, moxifloxacin, and metronidazole using a green micellar High Performance Liquid Chromatography-Ultraviolet method in bulk drugs, different commercial formulations, and spiked human plasma. The combined therapy of these three broad-spectrum antibiotics is used to cure refractory hidradenitis suppurativa (HS), an inflammatory condition affecting the skin. The sustainable separation was attained on a reversed-phase C18 Kinetex® column maintained at ambient temperature in less than 5 min. The mobile phase comprises 0.1 M sodium dodecyl sulfate (SDS) in water, pH 3.5, adjusted using o-phosphoric acid, and 10% n-butanol. The flow rate was 1 mL/min, with 10 μL injection volume and UV detection at 230 nm. The impact of three key significant variables, SDS concentration, n-butanol percentage, and the mobile phase pH, on suitability parameters was studied. ICH and FDA guidelines were committed to when validating the technique. The results showed linear calibration graphs with high precision and accuracy, in both pure and spiked plasma. The method is efficient, easy to use, and has a high sample throughput, making it suitable for routine analysis in the quality control department and therapeutic monitoring. It is also evaluated as a green-and-white substitute for traditional reported methods.

An Atlas of the Hidradenitis Suppurativa Transcriptome

INTRODUCTIONS

Hidradenitis suppurativa (HS) is a chronic inflammatory condition of the skin. Both genetic and environmental factors contribute to the risk of developing HS, but the pathogenesis of this disease is currently not fully understood. The aim of this study was to further current understanding of the molecular background of HS with the use of global transcriptome analyses.

METHODS

Transcriptome profiling of perilesional and lesional skin of five patients with HS and six healthy control patients was performed by next-generation sequencing. Groups of differentially expressed genes characteristic of the skin of patients with HS were shortlisted by bioinformatic analysis.

RESULTS

RNA sequencing followed by bioinformatic profiling revealed profound enrichment of inflammatory-related processes in both lesional and perilesional skin of patients with HS. There were, however, distinct differences in the gene expression profiles between the lesional and perilesional skin, with 1488 genes differentially expressed. Genes encoding typical proinflammatory cytokines were profoundly enriched within HS lesions. In contrast, those encoding mediators of extracellular matrix organization were highly expressed mostly in the perilesional area.

CONCLUSIONS

Our study provides novel insights into the mechanisms underlying the pathogenesis of HS, and the results also have potential clinical implications in both diagnosis and therapeutics.

Comprehensive Treatment and Gene Analysis of a Male Patient with Follicular Occlusion Tetrad with Fordyce Granules

Follicular occlusion tetrad (FOT) is a chronic inflammatory skin disease that seriously affects patients' quality of life. At present, there is no standard treatment plan for FOT. We report the case of a 50-year-old male patient diagnosed as having FOT with Fordyce granules and type 2 diabetes mellitus. During hospitalization, the patient received comprehensive and systematic treatment. The patient healed well after surgery and the 10-month follow-up revealed no recurrence. We found eight gene mutations by whole-exome sequencing (WES) of the patient's peripheral blood.

Gluteal Hidradenitis Suppurativa: Analysis of 83 Patients

BACKGROUND

In 2013, Canoui-Poitrine et al. identified three hidradenitis suppurativa (HS) phenotypes by a latent class (LC) analysis, based on anatomical sites of involvement.

OBJECTIVE

To improve the classification of the gluteal phenotype (LC3) patients given their diverse lesion types and differences in clinical profile.

MATERIAL AND METHODS

We designed a bicentric study gathering all LC3 patients (n=83) from two hospitals. We conducted a two-step cluster analysis among them and also compared their characteristics with the rest of the HS patients (n=661).

RESULTS

Compared with global HS series, LC3 patients were more frequently non-obese men, with smoking habit, an associated arthropathy, and a more frequent history of pilonidal sinus. The analysis of LC3 patients yielded two clusters: cluster 1 (38.3%) included elderly female patients, with later diagnosis of the disease and more sinus tracts; cluster 2 (61.7%) encompassed more men with earlier disease onset and more nodules and folliculitis lesions.

LIMITATIONS

The study's limitations include its retrospective nature, bicentric design, and small sample size.

CONCLUSION

The heterogeneous clinical presentation of HS makes it essential to have a good classification of the patients. Gluteal phenotype could actually be classified into two "subphenotypes" with a different clinical profiles and management.

Hidradenitis Suppurativa: An Understanding of Genetic Factors and Treatment

Hidradenitis suppurativa (HS), recognized as a chronic and debilitating skin disease, presents significant challenges in both diagnosis and treatment. This review explores the clinical manifestations, genetic landscape, and molecular mechanisms underlying HS. The disease's association with a predisposing genetic background, obesity, smoking, and skin occlusion underscores the complexity of its etiology. Genetic heterogeneity manifests in sporadic, familial, and syndromic forms, with a focus on mutations in the γ-secretase complex genes, particularly NCSTN. The dysregulation of immune mediators, including TNF-α, IL-17, IL-1β, and IL-12/23, plays a crucial role in the chronic inflammatory nature of HS. Recent advancements in genetic research have identified potential therapeutic targets, leading to the development of anti-TNF-α, anti-IL-17, anti-IL-1α, and anti-IL-12/23 therapies and JAK inhibitors. These interventions offer promise in alleviating symptoms and improving the quality of life for HS patients.

Therapeutic Potential of IL-1 Antagonism in Hidradenitis Suppurativa

The immunopathogenesis of HS is partially understood and exhibits features of an autoinflammatory disease; it is associated with the potential involvement of B cells and the contribution of Th1 or Th17 cell subsets. Recently, the pathogenic role of both innate immunity and IL-1 family cytokines in HS has been deeply investigated. Several agents targeting the IL-1 family pathway at different levels are currently available and under investigation for the treatment of HS. HS is still characterized by unmet clinical needs and represents an expanding field in the current scientific research. The aim of this narrative review is to describe the pathological dysregulation of IL-1 family members in HS and to provide an update on therapeutic strategies targeting IL-1 family cytokine signaling. Further clinical and preclinical data may likely lead to the enrichment of the therapeutic armamentarium of HS with IL-1 family cytokine antagonists.

Gluteal Hidradenitis Suppurativa: Analysis of 83 Patients

BACKGROUND

In 2013, Canoui-Poitrine et al. identified three hidradenitis suppurativa (HS) phenotypes by a latent class (LC) analysis, based on anatomical sites of involvement.

OBJECTIVE

To improve the classification of the gluteal phenotype (LC3) patients given their diverse lesion types and differences in clinical profile.

MATERIAL AND METHODS

We designed a bicentric study gathering all LC3 patients (n=83) from two hospitals. We conducted a two-step cluster analysis among them and also compared their characteristics with the rest of the HS patients (n=661).

RESULTS

Compared with global HS series, LC3 patients were more frequently non-obese men, with smoking habit, an associated arthropathy, and a more frequent history of pilonidal sinus. The analysis of LC3 patients yielded two clusters: cluster 1 (38.3%) included elderly female patients, with later diagnosis of the disease and more sinus tracts; cluster 2 (61.7%) encompassed more men with earlier disease onset and more nodules and folliculitis lesions.

LIMITATIONS

The study's limitations include its retrospective nature, bicentric design, and small sample size.

CONCLUSION

The heterogeneous clinical presentation of HS makes it essential to have a good classification of the patients. Gluteal phenotype could actually be classified into two "subphenotypes" with a different clinical profiles and management.

Hidradenitis suppurativa: new insights into disease mechanisms and an evolving treatment landscape

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic disabling and debilitating inflammatory disease with a high unmet medical need. The prevalence of HS reported in most studies is 1-2%, although it is likely to be under-reported and estimates vary globally owing to variance in data collection methods, ethnicity, geographical location and under-diagnosis. HS is characterized by persistent, painful cutaneous nodules, abscesses and draining tunnels commonly affecting the axillary, anogenital, inguinal and perianal/gluteal areas. Over time, chronic uncontrolled inflammation results in irreversible tissue destruction and scarring. Although the pathophysiology of HS has not been fully elucidated, the tumour necrosis factor (TNF)-α and interleukin (IL)-17 pathways have an important role, involving multiple cytokines. Currently, treatment options include topical medications; systemic therapies, including repeated and/or rotational courses of systemic antibiotics, retinoids and hormonal therapies; and various surgical procedures. The anti-TNF-α antibody adalimumab is currently the only biologic approved by both the US Food and Drug Administration and the European Medicines Agency for HS; however, its efficacy varies, with a clinical response reported in approximately 50% of patients in phase III trials. HS is a rapidly evolving field of discovery, with a diverse range of agents with distinct mechanisms of action currently being explored in clinical trials. Several other promising therapeutic targets have recently emerged, and agents targeting the IL-17 and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways are the most advanced in ongoing or completed phase III clinical trials. Alongside limited therapeutic options, significant challenges remain in terms of diagnosis and disease management, with a need for better treatment outcomes. Other unmet needs include significant diagnostic delays, thus missing the therapeutic 'window of opportunity'; the lack of standardized outcome measures in clinical trials; and the lack of established, well-defined disease phenotypes and biomarkers.

Janus-kinase inhibitors in dermatology: A review of their use in psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease

Recent studies on molecular pathways have elucidated novel therapeutic approaches in inflammatory and autoimmune skin disorders. Specifically, the dysregulation of the Janus kinase signal transducer and activator of transcription (JAK-STAT) cascade plays a central role in the pathogenesis of many skin conditions. JAK inhibitors, with their ability to selectively target immune responses, are potential treatment options. Using the National Library of Medicine, we provide a comprehensive review of the use of United States Food and Drug Administration (FDA)-approved and emerging JAK or tyrosine kinase 2 (TYK2) inhibitors in a wide range of dermatologic conditions, including psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. In patients with psoriasis, oral deucravacitinib (TYK2 inhibitor) has been approved as a once-daily therapy with demonstrated superiority and efficacy over apremilast and placebo and tolerable safety profiles. In patients with vitiligo, topical ruxolitinib (JAK1 inhibitor) is approved as a twice-daily treatment for repigmentation. The efficacy of several other JAK inhibitors has also been demonstrated in several clinical trials and case studies for systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. Further investigations with long-term clinical trials are necessary to confirm their utility in treatment and safety for these diseases.

Pathological and Therapeutical Implications of Pyroptosis in Psoriasis and Hidradenitis Suppurativa: A Narrative Review

This manuscript explores the role of pyroptosis, an inflammatory programmed cell death, in the pathogenesis of two chronic dermatoses, psoriasis and hidradenitis suppurativa (HS). The diseases, though clinically diverse, share common pathogenetic pathways involving the unbalanced interaction between the adaptive and innate immune systems. This review focuses on the molecular changes in psoriatic and HS skin, emphasizing the activation of dendritic cells, secretion of interleukins (IL-17, IL-22, and TNF-α), and the involvement of inflammasomes, particularly NLRP3. This manuscript discusses the role of caspases, especially caspase-1, in driving pyroptosis and highlights the family of gasdermins (GSDMs) as key players in the formation of pores leading to cell rupture and the release of proinflammatory signals. This study delves into the potential therapeutic implications of targeting pyroptosis in psoriasis and HS, examining existing medications like biologics and Janus kinase inhibitors. It also reviews the current limitations and challenges in developing therapies that selectively target pyroptosis. Additionally, the manuscript explores the role of pyroptosis in various inflammatory disorders associated with psoriasis and HS, such as inflammatory bowel disease, diabetes mellitus, and cardiovascular disorders. The review concludes by emphasizing the need for further research to fully elucidate the pathomechanisms of these dermatoses and develop effective, targeted therapies.

Neutrophil extracellular traps and neutrophilic dermatosis: an update review

Neutrophils have both antimicrobial ability and pathogenic effect in the immune system, neutrophil extracellular traps (NETs) formation is one of the representative behaviors of their dual role. NETs formation was triggered by pathogen-related components and pathogen non-related proteins as cytokines to exert its effector functions. Recent studies indicate that the pathogenicity of NETs contributed to several skin diseases such as psoriasis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and neutrophilic dermatosis. Especially in neutrophilic dermatosis, a heterogeneous group of inflammatory skin disorders characterized with sterile neutrophilic infiltrate on dermis, NETs formation was reported as the way of participation of neutrophils in the pathogenesis of these diseases. In this review, we describe the different processes of NETs formation, then summarized the most recent updates about the pathogenesis of neutrophilic dermatosis and the participation of NETs, including pyoderma gangrenosum and PAPA syndrome, Behçet syndrome, hidradenitis suppurativa, Sweet Syndrome, pustular dermatosis and other neutrophilic dermatosis. Furthermore, we discuss the link between NETs formation and the development of neutrophilic dermatosis.

Hidradenitis Suppurativa Is Associated with Severe Sexual Impairment

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder of the pilosebaceous unit, often affecting and deforming intimate regions. HS is associated with severe pain, pruritus, and constant, purulent, malodorous discharge expected to impair sexual health of patients.

METHODS

We performed a cross-sectional, multicentric study involving 199 German patients from the health services research project "Epidemiology and Care in Acne inversa (EpiCAi)." The sexual health, HS severity, and quality of life of the studied group were evaluated using a specially designed questionnaire.

RESULTS

Regardless of gender, HS has an enormous impact on patients' sexual health. The patients scored, on average, 28.8 ± 5.3 points on the Relation and Sexuality Scale (RSS). Multiple linear regression revealed that females and patients with Hurley III stage had higher sexual dysfunction (p = 0.012). Sexual dysfunction is associated with pain (β = 0.25), the number of active lesions, the affected areas (β = 0.14), and psychosocial aspects, including low quality of life (β = 0.404), stigmatization (β = 0.411), depression (β = 0.413), and anxiety (β = 0.300). Patients already see a substantial decrease in sexual frequency in the early stages of HS, while functional impairment and fear increase with the severity of the disease.

CONCLUSION

Sexual health and management of its dysfunctions should be part of a holistic approach to HS patients.

Efficacy and Safety of the Heat Shock Protein 90 Inhibitor RGRN-305 in Hidradenitis Suppurativa: A Parallel-Design Double-Blind Trial

Importance

Hidradenitis suppurativa is a painful immune-mediated disorder with limited treatment options; hence, a need exists for new treatments.

Objective

To evaluate the feasibility of heat shock protein 90 inhibition by RGRN-305 as a novel mechanism of action in treating moderate to severe hidradenitis suppurativa.

Design, Setting, and Participants

This was a parallel-design, double-blind, proof-of-concept, placebo-controlled randomized clinical trial conducted between September 22, 2021, and August 29, 2022, at the Department of Dermatology, Aarhus University Hospital in Denmark. The study included a 1- to 30-day screening period, a 16-week treatment period, and a 4-week follow-up period. Eligibility criteria included age 18 years or older and moderate to severe hidradenitis suppurativa with 6 or more inflammatory nodules or abscesses in at least 2 distinct anatomic regions. Of 19 patients screened, 15 patients were enrolled in the study. Intention-to-treat analysis was performed.

Interventions

Patients were randomly assigned (2:1) to receive oral RGRN-305, 250-mg tablet, or matching placebo once daily for 16 weeks.

Main Outcomes and Measures

The primary efficacy end point was the percentage of patients achieving Hidradenitis Suppurativa Clinical Response 50 (HiSCR-50) at week 16. Secondary efficacy end points included HiSCR-75 or HiSCR-90, Hidradenitis Suppurativa Physician's Global Assessment, Dermatology Life Quality Index scores, and a pain numeric rating scale. Safety was assessed by adverse events, physical examinations, clinical laboratory measurements, and electrocardiograms.

Results

A total of 15 patients were enrolled, completed the study, and were included in all analyses (10 [67%] female; median age, 29 [IQR, 23-41] years). The primary end point HiSCR-50 at week 16 was achieved by a higher percentage in the RGRN-305 group (60% [6 of 10]) than in the placebo group (20% [1 of 5]). Improvements were also observed across all secondary end points at week 16, including higher rates of the harder-to-reach HiSCR levels; 50% (5 of 10) achieved HiSCR-75 and 30% (3 of 10) achieved HiSCR-90, whereas none of the placebo-treated patients achieved HiSCR-75 or HiSCR-90. RGRN-305 was well tolerated, with no deaths or serious adverse events, and treatment-emergent adverse events were similarly frequent between the RGRN-305 and placebo groups.

Conclusions and Relevance

The findings of this trial suggest that heat shock protein 90 inhibition by RGRN-305 offers a novel mechanism of action in treating hidradenitis suppurativa, warranting further evaluation in larger trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT05286567.

Burden of Hidradenitis Suppurativa: A Systematic Literature Review of Patient Reported Outcomes

INTRODUCTION

Hidradenitis suppurativa (HS) has a profound negative impact on patients' health-related quality of life (HRQoL). Here we summarize the evidence on HRQoL and Patient Reported Outcomes (PROs) in patients with HS in real-world settings by conducting a systematic literature review (SLR) of observational studies.

METHODS

Data sources included MEDLINE, Embase & PsycINFO between January 1, 2010 and August 29, 2021, and conference proceedings between 2019 and 2021. Identified abstracts were reviewed and screened independently by two reviewers. Eligibility criteria included patients with HS of any severity, sample size ≥ 100, reporting PROs including HRQoL measures. Included studies were critically appraised.

RESULTS

Fifty-eight observational studies matched inclusion criteria. Dermatology Life Quality Index (DLQI) was the most commonly utilized instrument: 57% of included studies reported mean baseline DLQI scores, ranging between 8.4 and 16.9, indicating a very large impact on the patients' HRQoL. Higher scores were reported with increasing disease severity and among female patients. Pain was assessed mostly by an 11-point (0-10) numeric rating scale (NRS) with a mean baseline score ranging from 3.6 to 7.7 indicating moderate to high pain levels. There was a negative impact of HS on patients' psychological well-being, based on PRO scores related to depression and anxiety. A high proportion of sexual dysfunction was reported, with a larger impact on women than men. Work productivity and leisure activity were consistently found to be impaired in patients with HS.

CONCLUSIONS

All included studies reported a negative impact of HS on patients' lives. A diverse set of disease- and non-disease-specific PRO instruments were utilized highlighting the need for more consistent use of HS-specific validated PRO instruments to assess the impact of HS on the different aspects of patients' HRQoL to allow for data to be more meaningfully interpreted and compared in real-world settings. Patients with HS need better disease management approaches that address the observed low quality of life.

Cerebral Tuberculosis After Therapy With Adalimumab for Hidradenitis Suppurativa: A Rare Case

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with limited therapeutic options. Adalimumab, an anti-tumor necrosis factor-alpha (TNF-α) monoclonal antibody, was the first biological agent approved for the treatment of moderate to severe HS. Tuberculosis (TB) is a highly prevalent global public health problem, affecting individuals worldwide. Continuous immunosuppression from TNF-α treatment increases the risk of TB development. Isolated neurotuberculosis, in the absence of other symptoms, emerges as a rarely observed infection pattern in such patients. We present a case of a 23-year-old woman with severe HS undergoing treatment with adalimumab. After two years, she developed a pronounced occipital tension headache, constant nausea, and persistent fever. The patient's latent TB status was unknown without annual screening. Subsequent magnetic resonance imaging revealed a lesion in the cerebellar vermis. Immunosuppressive therapy was suspended and an etiological study was conducted; the only positive result was the interferon-gamma release assay. Empirically, antituberculosis treatment and prednisolone were initiated, leading to clinical and neurological improvement. After one year of treatment, symptoms resolved without neurological sequelae. This case highlights the importance of vigilant monitoring before, during, and after immunosuppressive treatment. Early recognition, discontinuation of anti-tumor necrosis factor medications, and appropriate management of TB are crucial to prevent complications.

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."

Detection of native, activated Notch receptors in normal human apocrine-bearing skin and in hidradenitis suppurativa

Notch signalling has generated considerable interest as a pathogenetic factor and a drug target in a range of human diseases. The gamma-secretase complex is crucial in the activation of Notch receptors by cleaving the intracellular domain allowing nuclear translocation. In recent years several mutations in gamma-secretase components have been discovered in patients with familial hidradenitis suppurativa (HS). This has led to hypotheses that impaired Notch signalling could be an important driver for HS in general, not only in the monogenic variants. However, no study has examined in situ Notch activation per se in HS, and some reports with conflicting results have instead been based on expression of Notch receptors or indirect measures of Notch target gene expression. In this study we established immunostaining protocols to identify native, activated Notch receptors in human skin tissue. The ability to detect changes in Notch activation was confirmed with an ex vivo skin organ model in which signal was reduced or obliterated in tissue exposed to a gamma-secretase inhibitor. Using these methods on skin biopsies from healthy volunteers and a general HS cohort we demonstrated for the first time the distribution of active Notch signalling in human apocrine-bearing skin. Quantification of activated NOTCH1 & NOTCH2 revealed similar levels in non-lesional and peri-lesional HS to that of healthy controls, thus ruling out a general defect in Notch activation in HS patients. We did find a variable but significant reduction of activated Notch in epidermis of lesional HS with a distribution that appeared related to the extent of surrounding tissue inflammation.

Therapeutic TNF Inhibitors Exhibit Differential Levels of Efficacy in Accelerating Cutaneous Wound Healing

Adalimumab but neither etanercept nor certolizumab-pegol has been reported to induce a wound-healing profile in vitro by regulating macrophage differentiation and matrix metalloproteinase expression, which may underlie the differences in efficacy between various TNF-α inhibitors in impaired wound healing in patients with hidradenitis suppurativa, a chronic inflammatory skin disease. To examine and compare the efficacy of various TNF inhibitors in cutaneous wound healing in vivo, a human TNF knock-in Leprdb/db mouse model was established to model the impaired cutaneous wound healing as seen in hidradenitis suppurativa. The vehicle group exhibited severe impairments in cutaneous wound healing. In contrast, adalimumab significantly accelerated healing, confirmed by both histologic assessment and a unique healing transcriptional profile. Moreover, adalimumab and infliximab showed similar levels of efficacy, but golimumab was less effective, along with etanercept and certolizumab-pegol. In line with histologic assessments, proteomics analyses from healing wounds exposed to various TNF inhibitors revealed distinct and differential wound-healing signatures that may underlie the differential efficacy of these inhibitors in accelerating cutaneous wound healing. Taken together, these data revealed that TNF inhibitors exhibited differential levels of efficacy in accelerating cutaneous wound healing in the impaired wound-healing model in vivo.

Mast cells are upregulated in hidradenitis suppurativa tissue, associated with epithelialized tunnels and normalized by spleen tyrosine kinase antagonism

Mast cells have traditionally been associated with allergic inflammatory responses; however, they play important roles in cutaneous innate immunity and wound healing. The Hidradenitis Suppurativa tissue transcriptome is associated with alterations in innate immunity and wound healing-associated pathways; however, the role of mast cells in the disease is unexplored. We demonstrate that mast cell-associated gene expression (using whole tissue RNAseq) is upregulated, and in-silico cellular deconvolution identifies activated mast cells upregulated and resting mast cells downregulated in lesional tissue. Tryptase/Chymase positive mast cells (identified using IHC) localize adjacent to epithelialized tunnels, fibrotic regions of the dermis and at perivascular sites associated with Neutrophil Extracellular Trap formation and TNF-alpha production. Treatment with Spleen Tyrosine Kinase antagonist (Fostamatinib) reduces the expression of mast cell-associated gene transcripts, associated biochemical pathways and the number of tryptase/chymase positive mast cells in lesional hidradenitis suppurativa tissue. This data indicates that although mast cells are not the most abundant cell type in Hidradenitis Suppurativa tissue, the dysregulation of mast cells is paralleled with B cell/plasma cell inflammation, inflammatory epithelialized tunnels and epithelial budding. This provides an explanation as to the mixed inflammatory activation signature seen in HS, the correlation with dysregulated wound healing and potential pathways involved in the development of epithelialized tunnels.

Unraveling the Epigenetic Tapestry: Decoding the Impact of Epigenetic Modifications in Hidradenitis Suppurativa Pathogenesis

Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin disorder, which typically occurs during puberty or early adulthood. The pathogenesis of HS is complex and multifactorial; a close interaction between hormonal, genetic, epigenetics factors, host-specific aspects, and environmental influences contributes to the susceptibility, onset, severity, and clinical course of this disease, although the exact molecular mechanisms are still being explored. Epigenetics is currently emerging as an interesting field of investigation that could potentially shed light on the molecular intricacies underlying HS, but there is much still to uncover on the subject. The aim of this work is to provide an overview of the epigenetic landscape involved in HS. Specifically, in this in-depth review we provide a comprehensive overview of DNA methylation/hydroxymethylation, histone modifications, and non-coding RNAs (such as microRNA-miRNA-132, miRNA-200c, miRNA-30a-3p, miRNA-100-5b, miRNA-155-5p, miRNA-338-5p) dysregulation in HS patients. An interesting element of epigenetic regulation in HS is that the persistent inflammatory milieu observed in HS lesional skin could be exacerbated by an altered methylation profile and histone acetylation pattern associated with key inflammatory genes. Deepening our knowledge on the subject could enable the development of targeted epigenetic therapies to potentially restore normal gene expression patterns, and subsequentially ameliorate, or even reverse, the progression of the disease. By deciphering the epigenetic code governing HS, we strive to usher in a new era of personalized and effective interventions for this enigmatic dermatological condition.

Risk of osteoarthritis in patients with hidradenitis suppurativa: a global federated health network analysis

BACKGROUND

Osteoarthritis and hidradenitis suppurativa (HS) share a common inflammatory pathway. However, whether patients with HS have higher risk developing osteoarthritis remained unclear.

METHODS

A retrospective cohort design was adopted in this study. Electronic medical records had been retrieved from the US collaborative network in the TriNetX research network. A propensity score matching of 1:1 was performed to match for covariates. In total, 50,931 patients with HS and the same amount of non-HS controls were identified for analyses. Hazard ratio (HR) of osteoarthritis in patient with HS was calculated.

RESULTS

Risk of patients with HS developing osteoarthritis was 1.37-fold higher than that of non-HS controls [95% confidence interval (CI), 1.21-1.55] when followed up for 1 year. The significance remained when the follow-up periods were extended to 3 years and 5 years. When osteoarthritis was stratified on occurring sites, the HR of knee osteoarthritis was 1.19 (95% CI, 1.09-1.29) and the HR of hip osteoarthritis was 1.17 (95% CI, 1.01-1.35) in the 5-year follow-up. The 5-year risk of osteoarthritis remained significant in sensitivity models.

CONCLUSION

Patients with HS were of high risk of developing osteoarthritis compared with people without HS. The clinical association was recommended to be considered while approaching patients with HS.

What should a surgeon know about hidradenitis suppurativa?

Otherwise known as Verneuil's disease, hidradenitis suppurative (HS) is a severe dermatosis of heterogeneous appearance affecting 1% of the population. Its pathophysiology is multifactorial, involving genetic predisposition, inflammatory disorder and environmental elements. Its diagnosis is based on the association of three clinical characteristics: characteristic lesions, typical localizations, and the chronic and recurrent nature of the lesions. Given its diversified aspects, diagnosis can be difficult to achieve. As its manifestations often include abscesses, it is important for the surgeon to know how to detect this pathology. The development of biologics has improved treatment of this disease, treatment that necessitates a multidisciplinary medical and surgical approach involving dermatologists and proctologists as well as surgeons. The objective of this report is to synthesize what a surgeon will need to know so as effectively treat HS patients.

Biology of Interleukin-17 and Novel Therapies for Hidradenitis Suppurativa

Skin disorders affect ∼40% of the human population. One of the most debilitating cutaneous disorders is Hidradenitis suppurativa (HS), a noncommunicable chronic inflammatory disease with an estimated global prevalence of 0.4% to 2.5%. In January 2011, high levels of IL-17 were discovered in skin lesions of HS patients. In the following years, translational and clinical research led to a better understanding of the pathogenesis of HS. In June 2023, more than 12 years after the initial note, secukinumab, an anti-IL-17A monoclonal antibody, was approved for the treatment of moderate to severe HS. This is the next milestone in improving the treatment of these patients after the approval of the anti-TNF-α monoclonal antibody adalimumab in 2015. In this review article, we present the IL-17 pathway in HS and discuss the use of secukinumab as a therapeutic option for this disease. Our review starts with a description of the epidemiology, clinical features, etiology, and pathogenesis of HS. An overview of the IL-17/IL-17 receptor system in general and a detailed description of the known facts about the expression and action of IL-17 in HS follow. Afterward, we consider the results of clinical trials evaluating the safety and efficacy of IL-17 inhibitors in HS. Finally, a comparison is made between secukinumab and adalimumab and the characteristics of the patients that may be particularly suitable for each of these biologics are described.

Transcriptomic Analysis of Hidradenitis Suppurativa: A Unique Molecular Signature with Broad Immune Activation

Hidradenitis suppurativa is a chronic inflammatory skin disease with limited treatment options. The poorly understood pathogenesis hinders the development of effective treatments; therefore, a pressing need exists to further elucidate the molecular mechanisms in hidradenitis suppurativa. This study investigated the underlying inflammatory pathways and cell types in hidradenitis suppurativa using transcriptomic approaches with RNA sequencing of lesional and non-lesional skin biopsies from hidradenitis suppurativa, which was jointly analyzed with previously published transcriptomic data from atopic dermatitis and psoriasis patients. The differential expression and pathway enrichment analyses demonstrated the activation of multiple inflammatory processes, including the innate and adaptive immune systems, implicated in the hidradenitis suppurativa pathogenesis. In agreement, hidradenitis suppurativa exhibited a unique and heterogeneous cell type signature involving lymphoid and myeloid cells such as B cells and macrophages. Furthermore, hidradenitis suppurativa displayed increased expression of TH1/2/17 signatures with no predominant TH signatures unlike psoriasis (TH1/17) and atopic dermatitis (TH2). In summary, our study provides molecular insights into the pathomechanisms in hidradenitis suppurativa, revealing a strong and widespread immune activation, which may benefit from treatment strategies offering a broad immunomodulation of various key inflammatory pathways. Our data not only corroborate previously reported findings but also enhance our understanding of the immune dysregulation in hidradenitis suppurativa, uncovering novel and potential therapeutic targets.

Molecular and functional changes in neutrophilic granulocytes induced by nicotine: a systematic review and critical evaluation

Background

Over 1.1 billion people smoke worldwide. The alkaloid nicotine is a prominent and addictive component of tobacco. In addition to tumors and cardiovascular disorders, tobacco consumption is associated with a variety of chronic-inflammatory diseases. Although neutrophilic granulocytes (neutrophils) play a role in the pathogenesis of many of these diseases, the impact of nicotine on neutrophils has not been systematically reviewed so far.

Objectives

The aim of this systematic review was to evaluate the direct influence of nicotine on human neutrophil functions, specifically on cell death/damage, apoptosis, chemotaxis, general motility, adhesion molecule expression, eicosanoid synthesis, cytokine/chemokine expression, formation of neutrophil extracellular traps (NETs), phagocytosis, generation of reactive oxygen species (ROS), net antimicrobial activity, and enzyme release.

Material and methods

This review was conducted according to the PRISMA guidelines. A literature search was performed in the databases NCBI Pubmed® and Web of Science™ in February 2023. Inclusion criteria comprised English written research articles, showing in vitro studies on the direct impact of nicotine on specified human neutrophil functions.

Results

Of the 532 originally identified articles, data from 34 articles were finally compiled after several evaluation steps. The considered studies highly varied in methodological aspects. While at high concentrations (>3 mmol/l) nicotine started to be cytotoxic to neutrophils, concentrations typically achieved in blood of smokers (in the nmol/l range) applied for long exposure times (24-72h) supported the survival of neutrophils. Smoking-relevant nicotine concentrations also increased the chemotaxis of neutrophils towards several chemoattractants, elevated their production of elastase, lipocalin-2, CXCL8, leukotriene B4 and prostaglandin E2, and reduced their integrin expression. Moreover, while nicotine impaired the neutrophil phagocytotic and anti-microbial activity, a range of studies demonstrated increased NET formation. However, conflicting effects were found on ROS generation, selectin expression and release of β-glucuronidase and myeloperoxidase.

Conclusion

Nicotine seems to support the presence in the tissue and the inflammatory and selected tissue-damaging activity of neutrophils and reduces their antimicrobial functions, suggesting a direct contribution of nicotine to the pathogenesis of chronic-inflammatory diseases via influencing the neutrophil biology.

Metformin has anti-inflammatory effects and induces immunometabolic reprogramming via multiple mechanisms in hidradenitis suppurativa

BACKGROUND

Targeting immunometabolism has shown promise in treating autoimmune and inflammatory conditions. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease involving painful lesions in apocrine gland-bearing skin. Therapeutic options for HS are limited and often ineffective; thus, there is a pressing need for improved treatments. To date, metabolic dysregulation has not been investigated in HS. As HS is highly inflammatory, we hypothesized that energy metabolism is dysregulated in these patients. Metformin, an antidiabetic drug, which is known to impact on cellular metabolic and signalling pathways, has been shown to have anti-inflammatory effects in cancer and arthritis. While metformin is not licensed for use in HS, patients with HS taking metformin show improved clinical symptoms.

OBJECTIVE

To assess the effect and mechanism of action of metformin in HS.

METHODS

To assess the effect of metformin in vivo, we compared the immune and metabolic profiles of peripheral blood mononuclear cells (PBMCs) of patients with HS taking metformin vs. those not taking metformin. To examine the effect of metformin treatment ex vivo, we employed a skin explant model on skin biopsies from patients with HS not taking metformin, which we cultured with metformin overnight. We used enzyme-linked immunosorbent assays, multiplex cytokine assays and quantitative real-time polymerase chain reaction (RT-PCR) to measure inflammatory markers, and Seahorse flux technology and quantitative RT-PCR to assess glucose metabolism.

RESULTS

We showed that metabolic pathways are dysregulated in the PBMCs of patients with HS vs. healthy individuals. In metformin-treated patients, these metabolic pathways were restored and their PBMCs had reduced inflammatory markers following long-term metformin treatment. In the skin explant model, we found that overnight culture with metformin reduced inflammatory cytokines and chemokines and glycolytic genes in lesions and tracts of patients with HS. Using in vitro assays, we found that metformin may induce these changes via the NLR family pyrin domain containing 3 (NLRP3) inflammasome and the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway, which is linked to glycolysis and protein synthesis.

CONCLUSIONS

Our study provides insight into the mechanisms of action of metformin in HS. The anti-inflammatory effects of metformin support its use as a therapeutic agent in HS, while its effects on immunometabolism suggest that targeting metabolism is a promising therapeutic option in inflammatory diseases, including HS.

Comparative diet-gut microbiome analysis in Crohn's disease and Hidradenitis suppurativa

Introduction

The chronic inflammatory skin disease Hidradenitis suppurativa (HS) is strongly associated with Crohn's Disease (CD). HS and CD share clinical similarities and similar inflammatory pathways are upregulated in both conditions. Increased prevalence of inflammatory disease in industrialised nations has been linked to the Western diet. However, gut microbiota composition and diet interaction have not been compared in HS and CD.

Methods

Here we compared the fecal microbiota (16S rRNA gene amplicon sequencing) and habitual diet of previously reported subjects with HS (n = 55), patients with CD (n = 102) and controls (n = 95).

Results and discussion

Patients with HS consumed a Western diet similar to patients with CD. Meanwhile, habitual diet in HS and CD was significantly different to controls. Previously, we detected differences in microbiota composition among patients with HS from that of controls. We now show that 40% of patients with HS had a microbiota configuration similar to that of CD, characterised by the enrichment of pathogenic genera (Enterococcus, Veillonella and Escherichia_Shigella) and the depletion of putatively beneficial genera (Faecalibacterium). The remaining 60% of patients with HS harboured a normal microbiota similar to that of controls. Antibiotics, which are commonly used to treat HS, were identified as a co-varying with differences in microbiota composition. We examined the levels of several inflammatory markers highlighting that growth-arrest specific 6 (Gas6), which has anti-inflammatory potential, were significantly lower in the 40% of patients with HS who had a CD microbiota configuration. Levels of the pro-inflammatory cytokine IL-12, which is a modulator of intestinal inflammation in CD, were negatively correlated with the abundance of health-associated genera in patients with HS. In conclusion, the fecal microbiota may help identify patients with HS who are at greater risk for development of CD.

Human dermal fibroblast subpopulations and epithelial mesenchymal transition signals in hidradenitis suppurativa tunnels are normalized by spleen tyrosine kinase antagonism in vivo

Hidradenitis Suppurativa is a chronic inflammatory disease of which the pathogenesis is incompletely understood. Dermal fibroblasts have been previously identified as a major source of inflammatory cytokines, however information pertaining to the characteristics of subpopulations of fibroblasts in HS remains unexplored. Using in silico-deconvolution of whole-tissue RNAseq, Nanostring gene expression panels and confirmatory immunohistochemistry we identified fibroblast subpopulations in HS tissue and their relationship to disease severity and lesion morphology. Gene signatures of SFRP2+ fibroblast subsets were increased in lesional tissue, with gene signatures of SFRP1+ fibroblast subsets decreased. SFRP2+ and CXCL12+ fibroblast numbers, measured by IHC, were increased in HS tissue, with greater numbers associated with epithelialized tunnels and Hurley Stage 3 disease. Pro-inflammatory CXCL12+ fibroblasts were also increased, with reductions in SFRP1+ fibroblasts compared to healthy controls. Evidence of Epithelial Mesenchymal Transition was seen via altered gene expression of SNAI2 and altered protein expression of ZEB1, TWIST1, Snail/Slug, E-Cadherin and N-Cadherin in HS lesional tissue. The greatest dysregulation of EMT associated proteins was seen in biopsies containing epithelialized tunnels. The use of the oral Spleen tyrosine Kinase inhibitor Fostamatinib significantly reduced expression of genes associated with chronic inflammation, fibroblast proliferation and migration suggesting a potential role for targeting fibroblast activity in HS.

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.

Disease Burden and Treatment Patterns Among US Patients with Hidradenitis Suppurativa: A Retrospective Cohort Study

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, autoinflammatory skin disease associated with many comorbidities. One biologic (adalimumab) is approved for HS. This study assessed the sociodemographic characteristics, comorbidities, treatment patterns, healthcare resource utilization (HCRU) and associated costs of patients with HS following biologic approval.

METHODS

This non-interventional, retrospective cohort study involved adult (≥ 18 years) and adolescent (12-17 years) patients diagnosed with HS in the United States (US) using Optum's de-identified Clinformatics® Data Mart Database during the period 1 January 2016 to 31 December 2018.

RESULTS

Of 42,843 identified patients, 10,909 met the incident HS patient criteria (10,230 adults, 628 adolescents, 51 patients aged <12 years). Patients were mostly diagnosed by a general practitioner/pediatrician (adults: 41.6%; adolescents: 39.6%) or dermatologist (adults: 22.1%; adolescents: 30.6%). Commonly reported Charlson comorbidities at pre-index in adult patients were diabetes without complications (20.4%), chronic pulmonary disease (16.4%) and diabetes with complications (9.0%), and the most frequent Elixhauser comorbidities were uncomplicated hypertension (38.3%), obesity (22.5%), uncomplicated diabetes (19.0%) and depression (17.4%). The burden of comorbidities generally increased over time after diagnosis in both adults and adolescents. HS-related surgical procedures were uncommon in the 2-years post-index period: an incision and drainage procedure was reported in 7.6% of adults and 6.4% of adolescents. Patients were predominantly treated with both topical and systemic antibiotic treatments (adults: 25.0% and 65.1%, respectively; adolescents: 41.7% and 74.5%, respectively). Biologic prescription was higher in adults than adolescents (3.5% vs. 1.8%). Total healthcare costs for adult and adolescent patients in the 2-years post-index period were US$42,143 and US$16,057, respectively, with outpatient costs accounting for the majority of these costs (US$20,980 and US$8408, respectively).

CONCLUSION

In adult and adolescent patients with HS, comorbidity burden continues to increase after diagnosis. All-cause and HS-specific HCRU and costs are high in adults and adolescents with HS. These findings support the need for a multidisciplinary comprehensive care strategy for patients with HS.

Upregulation of Caveolae-Associated Proteins in Lesional Samples of Hidradenitis Suppurativa: A Case Series Study

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition. HS disease management has proven difficult owing to an insufficient understanding of the immunological processes that drive its pathogenesis. We have demonstrated that misregulation of caveolae perturbs inflammatory responses, inhibits cutaneous wound healing, and contributes to immune privilege collapse in other hair follicle-related diseases. However, nothing is known about its role or the role of structural components of caveolae (caveolin [Cav1] 1, Cav2, and Cavin-1) in the pathophysiology of HS. We aimed to identify whether Cav1, Cav2, and Cavin-1 may serve as immunohistochemical markers of HS. Lesional and perilesional HS skin samples from patients (n = 7, mean age = 35.7 years, range = 20-57 years) with active HS and normal skin from control participants (n = 4, mean age = 36.7 years, range = 23-49 years) were used to assess Cav1, Cav2, and Cavin-1 expression and localization by immunofluorescence staining. HS samples demonstrated increased levels of Cav1 compared with normal skin, whereas Cav1, Cav2, and Cavin-1 were all elevated in hair follicles of lesional versus perilesional HS samples, suggesting a potentially novel therapeutic target and highlighting caveolae as potential biomarkers of HS.

Genetically predicted levels of circulating cytokines and the risk of six immune skin diseases: a two-sample Mendelian randomization study

Background

Circulating cytokines play a crucial role in the onset and progression of immune skin diseases. However, the causal relationships and the direction of causal effects require further investigation.

Methods

Two-sample Mendelian randomization (MR) analyses were conducted to assess the causal relationships between 41 circulating cytokines and six immune skin diseases including alopecia areata, chloasma, hidradenitis suppurativa (HS), lichen planus (LP), seborrheic dermatitis, and urticaria, using summary statistics from genome-wide association studies. Reverse MR analyses was performed to test for the reverse causation. Pleiotropy and heterogeneity tests were conducted to assess the robustness of the findings.

Results

Twelve unique cytokines showed a suggestive causal relationship with the risk of six immune skin diseases. Among them, the causal effects between 9 unique cytokines and immune skin diseases have strong statistical power. Additionally, the concentrations of six cytokines might be influenced by LP and urticaria. After Bonferroni correction, the following associations remained significant: the causal effect of beta-nerve growth factor on HS (odds ratio [OR] = 1.634, 95% confidence interval [CI] = 1.226-2.177, p = 7.97e-04), interleukin (IL)-6 on LP (OR = 0.615, 95% CI = 0.481-0.786, p = 1.04e-04), IL-4 on LP (OR = 1.099. 95% CI = 1.020-1.184, p = 1.26e-02), and IL-2 on urticaria (OR = 0.712, 95% CI = 0.531-0.955, p = 2.33e-02).

Conclusion

This study provides novel perspectives on the relationship between circulating cytokines and immune skin diseases, potentially providing valuable insights into their etiology, diagnostic approaches, and treatment.

Spatial transcriptomic profiling reveals the pathophysiology of early-stage hidradenitis suppurativa

We investigated the role of the epithelium of nodules in Hurley stage I hidradenitis suppurativa (HS) by using spatial transcriptomics to analyse the profiles of epithelial cells and dermal-infiltrating immune cells. Compared with epidermal cysts, genes related to bacterial response, inflammatory mediators and neutrophil degranulation pathways were upregulated in the epithelial cells of early-stage HS nodules. Our analysis of dermal-infiltrating immune cells surrounding the epithelium of nodules revealed significantly elevated levels of B-cell-related genes. Similarly to the sinus tract formation observed in moderate-to-severe HS, we propose that the production of inflammatory mediators in early-stage HS may involve the activation of keratinocytes and their interaction with dermal-infiltrating immune cells.

Is Exploration of Alternate Immune Pathways Needed in Hidradenitis Suppurativa? A Case of Atopic Dermatitis and Concurrent Hidradenitis Suppurativa Responding to Dupilumab

Hidradenitis suppurativa (HS) is an inflammatory dermatosis associated with overactive T helper 1/T helper 17 (Th1/Th17) cells. HS has been effectively treated with biologic medications; however, many such biologics lack large randomized controlled trials. Only one such biologic, adalimumab, has been approved by the US Food and Drug Administration (FDA) for the treatment of HS. Other such biologics currently being studied for HS downregulate Th1/Th17 inflammatory pathways. We describe a patient with atopic dermatitis (AD) and comorbid HS, both of which improved several months into treatment with dupilumab. Interestingly enough, dupilumab targets Th2-mediated inflammatory skin conditions through the inhibition of IL-4/IL-13 cytokines. While dupilumab is known for its success in treating Th2-mediated inflammation, this presents a paradox as HS is a Th1/Th17 inflammatory condition. This case highlights how the inflammatory process of HS is not fully understood and how biologic pharmacologic interventions need to be further studied to determine their efficacy in treating HS.

IL-17 Inhibition: A Valid Therapeutic Strategy in the Management of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with a significant negative impact on the quality of life of patients. To date, the therapeutic landscape for the management of the disease has been extremely limited, resulting in a profound unmet need. Indeed, adalimumab, an anti-tumor necrosis factor (TNF)-α monoclonal antibody, is the only approved biologic agent for HS, obtaining a therapeutic response in only 50% of HS patients. Numerous clinical trials are currently ongoing to test novel therapeutic targets in HS. The IL-17-mediated cascade is the target of several biologic agents that have shown efficacy and safety in treating moderate-to-severe HS. Both bimekizumab and secukinumab, targeting IL-17 in different manners, have successfully completed phase III trials with promising results; the latter has recently been approved by EMA for the treatment of HS. The aim of this review is to summarize the current state of knowledge concerning the relevant role of IL-17 in HS pathogenesis, highlighting the key clinical evidence of anti-IL-17 agents in the treatment of this disease.

The Effectiveness of Guselkumab in Patients With Hidradenitis Suppurativa Under Clinical Practice Conditions: A Spanish Multicentre Retrospective Study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic skin condition causing lesions in which high levels of interleukin (IL)-23 and T-helper17 cells are found. Adalimumab remains the only approved treatment. Guselkumab, an antibody targeting the p19 protein subunit of extracellular IL-23, is approved for the treatment of moderate-severe psoriasis, but evidence on its efficacy in treating HS is limited.

OBJECTIVES

To assess the effectiveness and safety of guselkumab in treating moderate-severe HS under clinical practice conditions.

METHODS

A multicentre retrospective observational study was carried out in 13 Spanish hospitals including adult HS patients treated with guselkumab within a compassionate use programme (March 2020-March 2022). Data referred to patient demographic and clinical characteristics at treatment initiation (baseline), patient-reported outcomes (Numerical Pain Rating Scale [NPRS] and Dermatology Life Quality Index [DLQI]), physician scores (International Hidradenitis Suppurativa Severity Score System [IHS4], HS Physical Global Score [HS-PGA] and Hidradenitis Suppurativa Clinical Response [HiSCR]) were recorded at baseline and at 16, 24, and 48weeks of treatment.

RESULTS

A total of 69 patients were included. Most (84.10%) had severe HS (HurleyIII) and had been diagnosed for over ten years (58.80%). The patients had been subjected to multiple non-biological (mean: 3.56) or biological (mean: 1.78) therapies, and almost 90% of those treated with biologics had received adalimumab. A significant decrease in IHS4, HS-PGA, NPRS, and DLQI scores was observed from baseline to 48weeks of guselkumab treatment (all P<.01). HiSCR was achieved in 58.33% and 56.52% of the patients at 16 and 24weeks, respectively. Overall, 16 patients discontinued treatment, mostly due to inefficacy (n=7) or loss of efficacy (n=3). No serious adverse events were observed.

CONCLUSIONS

Our results indicate that guselkumab may be a safe and effective therapeutic alternative for patients with severe HS that fail to respond to other biologics.

Adalimumab in conjunction with surgery compared with adalimumab monotherapy for hidradenitis suppurativa: A Randomized Controlled Trial in a real-world setting

BACKGROUND

Adalimumab, the only biologic registered for hidradenitis suppurativa, shows clinical response in up to 60% of patients, leaving many patients in need for other treatment options such as surgery.

OBJECTIVE

To compare the clinical effectiveness of adalimumab combined with surgery vs adalimumab monotherapy in patients with moderate to severe hidradenitis suppurativa.

METHODS

A pragmatic Randomized Controlled Trial was performed from August 2018 to July 2022. Primary outcome was the difference in mean International Hidradenitis Suppurativa Severity Score System reduction after 12 months of treatment with the difference in mean Dermatology Life Quality Index reduction as a key secondary outcome.

RESULTS

Thirty-one patients were included per arm. The mean International Hidradenitis Suppurativa Severity Score System at baseline was 23.9 ± 10.7 in the surgery group and 20.9 ± 16.4, in the monotherapy group. After 12 months of treatment the surgery group had a significantly greater reduction in International Hidradenitis Suppurativa Severity Score System compared with the monotherapy group (-19.1 ± 11.3 vs -7.8 ± 11.8, P < .001). Moreover, the surgery group showed a greater reduction in Dermatology Life Quality Index after treatment compared with the monotherapy group (-8.2 ± 6.2 vs -4 ± 7.7, P = .02).

LIMITATIONS

The study follow-up was too short to assess surgical recurrence rates.

DISCUSSION

Combining adalimumab with surgery resulted in greater clinical effectiveness and improved quality of life after 12 months in patients with moderate to severe hidradenitis suppurativa.

Quantitative Sensory Testing to Characterize Sensory Changes in Hidradenitis Suppurativa Skin Lesions

Importance

Pain is the most impactful symptom in patients with hidradenitis suppurativa (HS). Characterization of sensory profiles may improve understanding of pain mechanisms in HS and facilitate identification of effective pain management strategies.

Objective

To characterize somatosensory profiles in patients with HS at clinically affected and nonaffected sites compared with pain-free reference data.

Design, Setting, and Participants

This cross-sectional study was conducted at the Emory University Dermatology Clinic. It was hypothesized (1) that patients with HS would demonstrate hypersensitivity to pain in HS lesions and (2) that some patients would have sensory profiles consistent with complex pain mechanisms. Therefore, adults with dermatologist-diagnosed HS and at least 1 painful HS lesion at the time of testing were enrolled between September 10, 2020, and March 21, 2022. Patients with other diagnoses contributing to pain or neuropathy were excluded. Data analysis was conducted between March and April 2022.

Exposure

Quantitative sensory testing was performed on HS lesions and control skin according to a standardized protocol.

Main Outcomes and Measures

Quantitative sensory testing outcomes included innocuous thermal and mechanical sensitivity (cold, warmth, and light touch detection thresholds), noxious thermal and mechanical sensitivity (cold, heat, pinprick, and deep pressure pain thresholds and suprathreshold pinprick sensitivity), temporal summation of pinprick, paradoxical thermal sensations, and dynamic mechanical allodynia (pain upon light stroking of the skin). Sensitivity in HS lesions was compared with sensitivity in a control location (the hand) and in pain-free controls using t tests.

Results

This study included 20 participants with a median age of 35.5 (IQR, 30.0-46.5) years, the majority of whom were women (15 [75%]). In terms of race and ethnicity, 2 participants (10%) self-identified as Asian, 11 (55%) as Black, 6 (30%) as White, and 1 (5%) as more than 1 race or ethnicity. Compared with site-specific reference values from healthy, pain-free control participants, HS lesions were insensitive to innocuous cold and warmth, noxious heat, and light touch (t = -5.69, -10.20, -3.84, and 4.46, respectively; all P < .001). In contrast, HS lesions also demonstrated significant hypersensitivity to deep pressure pain (t = 8.36; P < .001) and cutaneous pinprick (t = 2.07; P = .046). Hypersensitivity to deep pressure pain was also observed in the control site (t = 5.85; P < .001). A subset of patients with HS displayed changes in pain processing that are often seen in neuropathic and nociplastic pain conditions, including hypersensitivity to repetitive pinprick (5 [26%]), paradoxical thermal sensations (3 [15%]), and pain upon light stroking of the skin (10 [50%]).

Conclusions and Relevance

The findings of this cross-sectional study suggest that HS involves local changes in the skin or its free nerve endings, possibly leading to peripheral neuropathy and alterations in the transduction of innocuous and noxious thermal and mechanical stimuli. For some patients, central nervous system changes in somatosensory processing may also occur, but confirmatory evidence is needed. Better understanding of neuropathic and nociplastic mechanisms in HS pain could lead to individually tailored treatments.

The Effectiveness of Guselkumab in Patients With Hidradenitis Suppurativa Under Clinical Practice Conditions: A Spanish Multicentre Retrospective Study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic skin condition causing lesions in which high levels of interleukin (IL)-23 and T-helper 17 cells are found. Adalimumab remains the only approved treatment. Guselkumab, an antibody targeting the p19 protein subunit of extracellular IL-23, is approved for the treatment of moderate-severe psoriasis, but evidence on its efficacy in treating HS is limited.

OBJECTIVES

To assess the effectiveness and safety of guselkumab in treating moderate-severe HS under clinical practice conditions.

METHODS

A multicentre retrospective observational study was carried out in 13 Spanish Hospitals including adult HS patients treated with guselkumab within a compassionate use programme (March 2020-March 2022). Data referred to patient demographic and clinical characteristics at treatment initiation (baseline), patient-reported outcomes (Numerical Pain Rating Scale [NPRS] and Dermatology Life Quality Index [DLQI]), physician scores (International Hidradenitis Suppurativa Severity Score System [IHS4], HS Physical Global Score [HS-PGA] and Hidradenitis Suppurativa Clinical Response [HiSCR]) were recorded at baseline and at 16, 24, and 48 weeks of treatment.

RESULTS

A total of 69 patients were included. Most (84.10%) had severe HS (Hurley III) and had been diagnosed for over ten years (58.80%). The patients had been subjected to multiple non-biological (mean 3.56) or biological (mean 1.78) therapies, and almost 90% of those treated with biologics had received adalimumab. A significant decrease in IHS4, HS-PGA, NPRS, and DLQI scores was observed from baseline to 48 weeks of guselkumab treatment (all p<0.01). HiSCR was achieved in 58.33% and 56.52% of the patients at 16 and 24 weeks, respectively. Overall, 16 patients discontinued treatment, mostly due to inefficacy (n=7) or loss of efficacy (n=3). No serious adverse events were observed.

CONCLUSIONS

Our results indicate that guselkumab may be a safe and effective therapeutic alternative for patients with severe HS that fail to respond to other biologics.

A proof-of-concept open-label clinical trial of spleen tyrosine kinase antagonism using fostamatinib in moderate-to-severe hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is an autoinflammatory disorder of keratinization with a prominence of B cells and plasma cells. Fostamatinib is a spleen tyrosine kinase inhibitor targeting B cells and plasma cells.

OBJECTIVES

To assess the safety, tolerability, and clinical response at week 4 and week 12 of fostamatinib in moderate-to-severe HS.

METHODS

Twenty participants were administered fostamatinib 100 mg twice a day for 4 weeks, escalating to 150 mg twice a day thereafter until week 12. Participants were assessed for adverse events and clinical response assessed by HiSCR (Hidradenitis Suppurativa Clinical Response Score) and IHS4 (International Hidradenitis Suppurativa Severity Score) as well as other outcomes including DLQI (Dermatology Life Quality Index), visual analog scale, and physician global assessment.

RESULTS

All 20 participants completed the week 4 and week 12 endpoints. Fostamatinib was well tolerated in this cohort with no grade 2/3 adverse events reported. A total of 85% achieved HiSCR at week 4 and 85% at week 12. The greatest reduction in disease activity was seen at weeks 4/5 with worsening in a proportion of patients thereafter. Significant improvements were seen in pain, itch, and quality of life.

CONCLUSIONS

Fostamatinib was well tolerated in this HS cohort with no serious adverse events and improvement in clinical outcomes. Targeting B cells/plasma cells may be a viable therapeutic strategy in HS and requires further exploration.

Shorter time to initiation of biologic therapy in the setting of a hidradenitis suppurativa specialty clinic

Hidradenitis suppurativa (HS) is a chronic condition with a significant psychological and physical burden but a paucity of effective treatments. Early intervention with adalimumab improves disease outcomes. Two previous studies in Denmark and Northern Ireland have identified a time of 8.2 and 2.9 years, respectively, from first HS systemic/dermatology consultation to commencing a biologic. We aimed to evaluate the time from disease onset and from first specialty HS clinic review to the initiation of biologic therapy. We retrospectively reviewed 34 patients on biologic treatment for HS. The mean diagnostic delay was 12.4 years. The mean time from disease onset to biologic initiation was 14.8 years. Prior to a biologic, patients received a median of 3.3 treatments from the specialty HS clinic. The median time to biologic from first presentation at the specialty HS clinic was 1 year. This is shorter than the therapeutic delay reported in dermatology clinics in Denmark and Northern Ireland, providing evidence on the importance of specialized HS treatment. However, to make an impact with specialized HS care and earlier biologic initiation, diagnostic delay needs to be reduced.

Targeting the NLRP3 inflammasome reduces inflammation in hidradenitis suppurativa skin

BACKGROUND

Treatment for the debilitating disease hidradenitis suppurativa (HS) is inadequate in many patients. Despite an incidence of approximately 1%, HS is often under-recognized and underdiagnosed, and is associated with a high morbidity and poor quality of life.

OBJECTIVES

To gain a better understanding of the pathogenesis of HS, in order to design new therapeutic strategies.

METHODS

We employed single-cell RNA sequencing to analyse gene expression in immune cells isolated from involved HS skin vs. healthy skin. Flow cytometry was used to quantify the absolute numbers of the main immune populations. The secretion of inflammatory mediators from skin explant cultures was measured using multiplex and enzyme-linked immunosorbent assays.

RESULTS

Single-cell RNA sequencing analysis identified a significant enrichment in the frequency of plasma cells, T helper (Th) 17 cells and dendritic cell subsets in HS skin, and the immune transcriptome was distinct and more heterogeneous than healthy skin. Flow cytometry revealed significantly increased numbers of T cells, B cells, neutrophils, dermal macrophages and dendritic cells in HS skin. Genes and pathways associated with Th17 cells, interleukin (IL)-17, IL-1β and the NLRP3 inflammasome were enhanced in HS skin, particularly in samples with a high inflammatory load. Inflammasome constituent genes principally mapped to Langerhans cells and a subpopulation of dendritic cells. The secretome of HS skin explants contained significantly increased concentrations of inflammatory mediators, including IL-1β and IL-17A, and culture with an NLRP3 inflammasome inhibitor significantly reduced the secretion of these, as well as other, key mediators of inflammation.

CONCLUSIONS

These data provide a rationale for targeting the NLRP3 inflammasome in HS using small-molecule inhibitors that are currently being tested for other indications.