Hidradenitis Suppurativa: A Perspective on Genetic Factors Involved in the Disease

A Patient With Concurrent Hidradenitis Suppurativa and Porokeratosis Palmaris et Plantaris Disseminata: Case Report and Review of Autoinflammatory Keratinization Diseases

The term autoinflammatory keratinization diseases (AIKDs) was recently proposed as a unifying concept for diseases characterized by inflammation in the epidermis and upper dermis which leads to hyperkeratosis, caused by genetic perturbations of the innate immune system. We present a case of a patient with hidradenitis suppurativa and porokeratosis, two AIKDs, followed by a review of these conditions as well as other AIKDs. This case was distinguished by hypertrophic porokeratoses involving cystic hair follicles, showing histopathologic features of both conditions within single biopsy specimens. The patient's course was additionally complicated by SCC arising within a porokeratosis. Our case demonstrates a rare overlap of two AIKDs, occurring not only within the same patient but also within the same lesions.

Endotyping Insulin-Glucose Homeostasis in Hidradenitis Suppurativa: The Impact of Diabetes Mellitus and Inflammation

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease often associated with metabolic disorders such as diabetes mellitus. Recent research suggests a link between systemic inflammation and insulin-glucose dysregulation in HS. This study investigates the relationship between insulin-glucose homeostasis, diabetes mellitus and the haptoglobin concentration in HS patients. Methods: We assessed 95 HS patients and 49 controls using validated fasting-based function tests, including the Structural Parameter Inference Approach (SPINA), Homeostasis Model Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI). Results: The HS patients had a significantly higher fasting insulin concentration (97.2 vs. 69.0 pmol/L, p = 0.035), increased insulin resistance (HOMA-IR: 3.47 vs. 2.57, p = 0.016) and impaired insulin sensitivity (SPINA-GR: 1.34 vs. 1.76 mol/s, p = 0.017). In diabetes, the insulin sensitivity was more strongly reduced (SPINA-GR: 0.61 vs. 1.41 mol/s, p = 0.0057) and the insulin resistance increased (HOMA-IR: 7.3 vs. 3.2, p = 0.017). Higher haptoglobin concentrations were accompanied by worse glycaemic control, demonstrating a significantly elevated fasting glucose (5.77 vs. 5.11 mmol/L, p = 0.043) concentration and HbA1c (5.7% vs. 5.4%, p = 0.0081) fraction. Conclusions: Our findings suggest that chronic inflammation in HS contributes to metabolic dysregulation, worsening insulin resistance and glycaemic control, particularly in those with elevated haptoglobin or diabetes.

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.

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.

Unlocking the Mechanisms of Hidradenitis Suppurativa: Inflammation and miRNA Insights

Inflammatory skin diseases impose a significant burden on patients and healthcare systems worldwide. Among these, hidradenitis suppurativa (HS) is particularly notable for its chronic and recurrent nature. Recurrent nodules, abscesses, and scarring in apocrine gland-rich areas characterize the disease, including the groin, axillae, and perianal regions. Despite its considerable physical and psychological impact, the precise mechanisms driving HS remain elusive. Recent advancements in understanding the inflammatory processes involved in HS have highlighted the TNF-alpha, IL-1β, and IL-17/IL-23 pathways, which play crucial roles in initiating and perpetuating the disease. Moreover, specific microRNAs (miRNAs), such as miR-24-1-5p, miR146a-5p, mirR-26a-5p, miR-206, miR-338-3p, and miR-338-5p, are involved in these inflammatory processes. Dysregulation of these miRNAs contributes to aberrant cytokine expression and persistent inflammation, foreseeably exacerbating HS disease progression. This narrative review hypothesizes that miRNA dysregulation triggers aberrant expression in specific inflammatory pathways, contributing to HS's clinical manifestations and progression. We explore the implicated miRNAs' potential as biomarkers for earlier disease detection and as novel therapeutic targets. Identifying miRNA dysregulation offers new opportunities for earlier and more accurate diagnosis, potentially allowing clinicians to intervene before severe disease manifestations occur. Furthermore, therapeutic strategies to modulate miRNA expression could target the inflammatory pathways driving HS, leading to more personalized and effective treatments. This review also discusses future research directions to enhance the clinical management of HS. A better understanding of miRNA involvement in HS offers new avenues for research and management, ultimately improving patient outcomes and quality of life.

Equity and Outcome Events in Hidradenitis Suppurativa: Exploring Effect Modifiers Associated with Diagnostic Delay in the Real World

INTRODUCTION

Patients with hidradenitis suppurativa (HS) experience significantly delayed diagnoses of 7-10 years from symptom onset on average, but the reasons for this remain largely unknown. This study investigated drivers of diagnostic delay from the perspective of healthcare system equity.

METHODS

A literature review was performed to identify published factors associated with delayed HS diagnosis to inform data analysis. Clinical and demographic data from the Adelphi HS Disease Specific Programme (DSP)™, a real-world cross-sectional survey of dermatologists and their consulting patients in France, Germany, Italy, Spain, the UK and the USA in 2020/2021, were used to model factors influencing delay to diagnosis from onset of symptoms and first consultation.

RESULTS

Factors influencing delay to HS diagnosis in the literature with the most available evidence were misdiagnosis, delay in specialist referral and patient embarrassment. Data analysis revealed that increasing age was associated with reduced diagnostic delay after symptom onset. Patients with HS who were White or in Germany were also more likely to receive a faster diagnosis. Smokers, patients with concomitant conditions, or a family history of HS were slower to be diagnosed. When time to diagnosis following first consultation was assessed, increasing age was associated with quicker diagnosis. Moreover, patients with a family history of HS were diagnosed quicker, whereas those with high body mass index, more concomitant conditions, in employment, managed by multiple physicians or European were more delayed.

CONCLUSION

On the basis of a thorough analysis of real-world data, multiple factors that potentially influenced the timely diagnosis of HS have been identified. For the first time, this study quantifies the relative impact of these modifiers, providing valuable insights into areas that require attention for faster diagnoses and improved disease outcomes.

Exome Profiling Suggests Combined Effect of Myeloperoxidase, Toll-Like Receptors, and Metallopeptidase in Hidradenitis Suppurativa

BACKGROUND

Hidradenitis suppurativa, also called acne inversa, is a chronic skin inflammatory condition involving hair follicles, sebaceous glands, and apocrine glands. Symptoms can be variable in intensity, ranging from mild to severe. The exact causes of hidradenitis suppurativa are not fully understood, but the etiology is presumed to be multifactorial, encompassing genetics and environmental factors.

METHODS

Two families presented with hidradenitis suppurativa with an autosomal dominant pattern. We performed whole-exome sequencing in two unrelated patients from the two families.

RESULTS

We identified two and three variants in the two families, respectively. Variants involved the TLR2 and MPO genes in the first family and the MMP2, GJB2, and TLR4 genes, some of which have already been previously reported as possible candidates for hidradenitis suppurativa.

CONCLUSION

It is very likely that variants in a single gene only rarely cause the condition and that most cases, especially familial hidradenitis suppurativa cases, may more probably take the form of polygenic disorders.

Approaches based on miRNAs in Behçet's Disease: Unveiling pathogenic mechanisms, diagnostic strategies, and therapeutic applications

Behçet's Disease (BD) is an intricate medical puzzle, captivating researchers with its enigmatic pathogenesis. This complex ailment, distinguished by recurrent mouth and genital lesions, eye irritation, and skin injuries, presents a substantial obstacle to therapeutic research. This review explores the complex interaction of microRNAs (miRNAs) with BD, highlighting their crucial involvement in the disease's pathophysiology. miRNAs, recognized for regulatory influence in diverse biological processes, hold a pivotal position in the molecular mechanisms of autoimmune diseases, such as BD. The exploration begins with examining miRNA biogenic pathways and functions, establishing a foundational understanding of their regulatory mechanisms. Shifting to the molecular landscape governing BD, the review highlights miRNA-mediated impacts on critical signaling pathways like Notch, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and protein kinase B (AKT)/mammalian target of rapamycin (mTOR), offering insights into intricate pathophysiological mechanisms. Dissecting the immunological landscape reveals the profound influence of miRNAs on BD, shedding light on the intricate modulation of immune responses and offering novel perspectives on disease etiology and progression. Beyond molecular intricacies, the review explores the clinical relevance of miRNAs in BD, emphasizing their potential as diagnostic and prognostic indicators. The discussion extends to the promising realm of miRNA-based therapeutic interventions, highlighting their potential in alleviating symptoms and altering disease progression. This comprehensive review, serving as a valuable resource for researchers, clinicians, and stakeholders, aims to decipher the intricate molecular tapestry of BD and explore the therapeutic potential of miRNAs.

Comprehensive Catalog of Variants Potentially Associated with Hidradenitis Suppurativa, Including Newly Identified Variants from a Cohort of 100 Patients

Hidradenitis suppurativa (HS) is a chronic skin disease characterized by painful, recurrent abscesses, nodules, and scarring, primarily in skin folds. The exact causes of HS are multifactorial, involving genetic, hormonal, and environmental factors. It is associated with systemic diseases such as metabolic syndrome and inflammatory bowel disease. Genetic studies have identified mutations in the γ-secretase complex that affect Notch signaling pathways critical for skin cell regulation. Despite its high heritability, most reported HS cases do not follow a simple genetic pattern. In this article, we performed whole-exome sequencing (WES) on a cohort of 100 individuals with HS, and we provide a comprehensive review of the variants known to be described or associated with HS. 91 variants were associated with the γ-secretase complex, and 78 variants were associated with other genes involved in the Notch pathway, keratinization, or immune response. Through this new genetic analysis, we have added ten new variants to the existing catalogs. All variants are available in a .vcf file and are provided as a resource for future studies.

Essentials of hidradenitis suppurativa: a comprehensive review of diagnostic and treatment perspectives

Hidradenitis suppurativa, or acne inversa, is a chronic inflammatory skin condition with recurrent inflammatory nodules, abscesses, subcutaneous tracts, and scars. This condition may cause severe psychological distress and reduce the quality of life for affected individuals. It is considered to have one of the most damaging effects on quality of life of any skin disorder as a result of the discomfort and foul-smelling discharge from these lesions. Although the pathophysiology of HS is still unclear, multiple factors, including lifestyle, genetic, and hormonal factors, have been associated with it. The pathogenesis of HS is very complex and has wide clinical manifestations; thus, it is quite challenging to manage and often requires the use of combination treatments that must be tailored according to disease severity and other patient-specific factors. Although lifestyle changes, weight loss, quitting smoking, topical treatments, and oral antibiotics are adequate for mild cases, the challenge for healthcare professionals is dealing with moderate-to-severe HS, which often does not respond well to traditional approaches. This literature review, consisting of an overview of the various assessment tools and therapy strategies available for the diagnosis and treatment of HS from published literature, aims to be a guide for practicing clinicians in dealing with the complexities associated with this disease.

Improving hidradenitis suppurativa management: consensus statements from physicians and patients' perspectives

Hidradenitis suppurativa (HS) is a frequent chronic inflammatory skin condition primarily affecting areas rich in apocrine sweat glands, presenting with comedones, papules, nodules, and abscesses, as well as tunnels and hypertrophic scarring. Despite its prevalence and impact on quality of life, the pathogenesis of HS remains incompletely understood. Notably, its diagnosis often suffers from delays and misidentification, therefore an improved education for healthcare providers is mandatory. Moreover, HS is frequently associated with systemic comorbidities and a multidisciplinary approach is suggested for its management. Recognizing these challenges, a group of Italian HS experts and patients convened to develop consensus guidelines via the Nominal Group Technique. Through iterative meetings and remote collaboration, they identified key areas for improvement and formulated consensus statements to guide healthcare providers in delivering optimal care. This collaborative effort highlights the importance of standardized approaches and interdisciplinary collaboration in managing HS effectively.

Hidradenitis Suppurativa in the SARS-CoV-2 Pandemic: Investigation of Trigger Factors in a Single Center

Background: Hidradenitis suppurativa (HS) is a debilitating, chronic inflammatory disease associated with multiple triggers. As the world struggles with the global COVID-19 pandemic, it is important to review the trigger factors for chronically ill HS patients during the COVID-19 pandemic. This work investigates the self-described trigger factors of HS patients that emerged during the COVID-19 outbreak. Methods: We anonymously surveyed 110 HS patients during the SARS-CoV-2 pandemic using a 25-question questionnaire that included trigger factors for deterioration. Demographic, personal, and HS-specific information was also collected to identify potential trigger factors for HS exacerbation. All HS patients were asked if their HS had worsened compared to the time before the pandemic. Results: Compared to before the pandemic, 20% of HS patients (n = 22) reported a worsening of HS. Patients with an HS exacerbation were significantly more likely to avoid contact with a doctor than those without an exacerbation (45.5% vs. 18.2%; p = 0.007). HS involvement, severity, exercise activity, and BMI had no association with worsening HS (p > 0.05). Interestingly, dietary changes and increased consumption of sweets and treats were associated with worsening HS (p = 0.011 and p = 0.013). Specifically, eating more sweets and treats was associated with a 6-fold increased risk of worsening HS. The results suggest that diet has an important influence on HS relapses. Further investigation is needed to determine whether diet is a triggering factor independent of the SARS-CoV-2 pandemic. In addition, gluteal HS involvement was associated with a more than 4.3-fold risk of HS exacerbation. Conclusions: In the management of HS patients, it is important to consider that gluteal involvement and the consumption of sweets are more often associated with deterioration.

Ustekinumab in Hidradenitis Suppurativa: A Systematic Review and Meta-analysis

INTRODUCTION

Hidradenitis suppurativa (HS) is a frequently debilitating, inflammatory skin condition. Patients may have a limited response to adalimumab, currently the only Food and Drug Administration (FDA)-approved biologic treatment for HS. Ustekinumab is an interleukin-12/23 inhibitor that has been utilized in HS, but there is a lack of an updated systematic review on its efficacy and safety. The aim of this study is to perform a systematic review and meta-analysis of the literature on the efficacy and safety of ustekinumab for HS.

METHODS

In October 2022, MEDLINE and Embase databases were searched for articles on ustekinumab in HS. Data extraction was performed on relevant articles by two reviewers. The primary study outcome was the pooled response rate of HS to ustekinumab. A fixed-effects meta-analysis was performed, and Cochran's Q statistic and I squared index were used to assess heterogeneity. Statistical significance was determined at p < 0.05. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.

RESULTS

From 2012 to 2022, ten articles (nine case series and one prospective trial) with 88 patients met the inclusion criteria. Patients with reported disease severity had Hurley stage II (17.6%, 12/68) or III (82.4%, 56/68) disease. The majority (80.7%, 71/88) had previously failed at least one biologic treatment. A meta-analysis of all ten studies showed a pooled response rate of 67% (95% CI 0.57-0.76). Study limitations include a small number of patients and randomized controlled trials (RCTs).

CONCLUSIONS

Ustekinumab may be a helpful treatment option to consider for HS that is recalcitrant to first-line biologic therapies, but RCTs are needed to determine optimal dosing regimens and the specific patient populations that would benefit the most from this agent.

Efficacy and safety of bimekizumab in patients with moderate-to-severe hidradenitis suppurativa (BE HEARD I and BE HEARD II): two 48-week, randomised, double-blind, placebo-controlled, multicentre phase 3 trials

BACKGROUND

Patients with hidradenitis suppurativa have substantial unmet clinical needs and scarce therapeutic options. We aimed to assess the efficacy and safety of bimekizumab, a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F and IL-17A, in patients with moderate-to-severe hidradenitis suppurativa.

METHODS

BE HEARD I and II were two identically designed, 48-week randomised, double-blind, placebo-controlled, multicentre phase 3 trials. Patients aged 18 years or older with moderate-to-severe hidradenitis suppurativa were randomly assigned 2:2:2:1 using interactive response technology (stratified by worst Hurley Stage at baseline and baseline systemic antibiotic use) to receive subcutaneous bimekizumab 320 mg every 2 weeks; bimekizumab 320 mg every 2 weeks to week 16, then every 4 weeks to week 48; bimekizumab 320 mg every 4 weeks to week 48; or placebo to week 16, then bimekizumab 320 mg every 2 weeks. The primary outcome was an hidradenitis suppurativa clinical response of at least 50%, defined as a reduction in total abscess and inflammatory nodule count of at least 50% from baseline with no increase from baseline in abscess or draining tunnel count (HiSCR50) at week 16. Efficacy analyses included all randomly assigned study patients (intention-to-treat population). Safety analyses included all patients who received at least one full or partial dose of study treatment in the safety set, and of bimekizumab in the active-medication set. These trials are registered at ClinicalTrials.gov, NCT04242446 and NCT04242498, and both are completed.

FINDINGS

Patients for BE HEARD I were recruited from Feb 19, 2020, to Oct 27, 2021, and 505 patients were enrolled and randomly assigned. Patients for BE HEARD II were recruited from March 2, 2020, to July 28, 2021, and 509 patients were enrolled and randomly assigned. The primary outcome at week 16 was met in the group who received bimekizumab every 2 weeks using modified non-responder imputation; higher responder rates were observed with bimekizumab versus placebo in both trials: 138 (48%) of 289 patients versus 21 (29%) of 72 patients in BE HEARD I (odds ratio [OR] 2·23 [97·5% CI 1·16-4·31]; p=0·0060) and 151 (52%) of 291 patients versus 24 (32%) of 74 patients in BE HEARD II (2·29 [1·22-4·29]; p=0·0032). In BE HEARD II, HiSCR50 was also met in the group who were administered bimekizumab every 4 weeks (77 [54%] of 144 vs 24 [32%] of 74 with placebo; 2·42 [1·22-4·80]; p=0·0038). Responses were maintained or increased to week 48. Serious treatment-emergent adverse events were reported in 40 (8%) patients in BE HEARD I and in 24 (5%) patients in BE HEARD II treated with bimekizumab over 48 weeks. The most frequently reported treatment-emergent adverse events to week 48 were hidradenitis in both trials, in addition to coronavirus infection and diarrhoea in BE HEARD I, and oral candidiasis and headache in BE HEARD II. One death was reported across the two trials, and was due to congestive heart failure in a patient with substantial cardiovascular history treated with bimekizumab every 2 weeks in BE HEARD I (considered unrelated to bimekizumab treatment by the investigator). No new safety signals were observed.

INTERPRETATION

Bimekizumab was well tolerated by patients with hidradenitis suppurativa and produced rapid and deep clinically meaningful responses that were maintained up to 48 weeks. Data from these two trials support the use of bimekizumab for the treatment of patients with moderate-to-severe hidradenitis suppurativa.

FUNDING

UCB Pharma.

Can telomeric changes orchestrate the development of autoinflammatory skin diseases?

Telomeres, the safeguarding caps at the tips of chromosomes, are pivotal in the aging process of cells and have been linked to skin ailments and inflammatory conditions. Telomeres undergo a gradual reduction in length and factors such as oxidative stress hasten this diminishing process. Skin diseases including inflammatory conditions can be correlated with the shortening of telomeres and the persistent activation of DNA damage response in skin tissues. Telomere dysfunction could disrupt the balance of the skin, impairs wound healing, and may contribute to abnormal cytokine production. Skin aging and processes related to telomeres may function as one of the triggers for skin diseases. The presence of proinflammatory cytokines and dysfunctional telomeres in conditions such as Dyskeratosis Congenita implies a possible connection between the shortening of telomeres and the onset of chronic inflammatory skin disorders. In autoinflammatory skin diseases, chronic inflammation hinders wound healing thus aggravating the progression of the disease. The NF-ĸB pathway might contribute to the initiation or progression of chronic disorders by influencing mechanisms associated with telomere biology. The intricate connections between telomeres, telomerase, telomere-associated proteins, and skin diseases are still a complex puzzle to be solved. Here, we provide an overview of the impact of telomeres on both health and disease with a specific emphasis on their role in skin, inflammation and autoinflammatory skin disorders.

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.

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.

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.

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.

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.

The Pathogenesis and Treatment of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a multifactorial disease involving the skin and subcutaneous tissues characterized by deep-seated, painful nodules and abscesses with draining sinus tracts. It affects mostly younger individuals between the ages of 18 and 34. The discomfort and embarrassment that patients affected by HS experience negatively impact their daily lives. It is associated with decreased quality of life and high rates of comorbid depression and anxiety. The rate of depression in HS was reported to be as high as 26%. Its pathogenesis is multifactorial and as such requires a multimodal approach to treatment, which subsequently is reviewed here. Moreover, the pathogenesis of HS is complex and only partially understood. Autoinflammation is the key driver of disease development and is linked with dysregulated inflammasome activation with the subsequent production of inflammatory cytokines. Genetics and cutaneous microbiome play a role in the development of chronic inflammation and lesion formation. Risk factors such as obesity, metabolic syndrome, diabetes, and smoking also add to the systemic inflammation. Targeting these risk factors is a key aspect of the treatment of HS. Lifestyle modifications are used in conjunction with pharmacotherapy and procedures to effectively manage the disease.

Navigating the Multidimensional Impact of Living with Hidradenitis Suppurativa: An In-Depth Netnographic Study on Social Media Platforms

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic skin condition causing considerable distress. It impacts mobility, social interaction, and quality of life. In Brazil, there is a notable gap in epidemiological data and patient experiences regarding HS.

METHODS

This study, spanning 2019 to 2022, employed netnography to probe the experiences of Brazilian patients with HS. This approach gleans insights from online interactions, offering a direct view into patients' lives.

RESULTS

Notably, the data illuminated the challenges patients face, such as difficulties in obtaining a diagnosis and the complexities involved in managing a chronic, and often debilitating, condition. Furthermore, patients' experiences with various treatments, encompassing antibiotics, biologic agents, lifestyle alterations, surgical procedures, and alternative remedies, were also examined.

CONCLUSION

By undertaking a longitudinal analysis of patient interactions, the study aimed to offer a richer understanding of HS, from its diagnosis to its treatment. It underscores the necessity for a more patient-centered approach when managing this condition. We hope that this enhanced understanding can facilitate better care for those affected by HS.

Hidradenitis suppurativa and psoriasis: the odd couple

Psoriasis and hidradenitis suppurativa are chronic inflammatory skin diseases that can develop together, negatively impacting on the patient's quality of life. We aimed to review the most up-to-date information regarding the epidemiology, pathogenesis, clinical presentation and possible therapeutical choices in patients with both psoriasis and hidradenitis suppurativa, thus linking these two autoimmune and autoinflammatory conditions. A narrative review of articles dating from 2017 to 2022 has been performed using the PubMed database. We analyzed the case reports and case series found in the literature regarding patients who suffered from both psoriasis and HS. Psoriasis arose before hidradenitis suppurativa in the majority of cases, while only a minority of them had hidradenitis suppurativa before psoriasis. Interestingly, some patients suffered from paradoxical hidradenitis suppurativa following biological therapy administered to treat the already present psoriasis. Lastly, new biological drugs have been marketed with great success for the outcome of psoriasis, but similar progress did not happen for hidradenitis. Novel therapeutic approaches and lines of research are needed for the treatment of these pathologies, even if concomitant, in order to improve patient's quality of life.

Efficacy and Safety of Biologics and Small Molecules for Moderate-to-Severe Hidradenitis Suppurativa: A Systematic Review and Network Meta-Analysis

Background: Treatment of hidradenitis suppurativa (HS) is difficult and current guidelines are based mainly on expert opinion and non-randomized controlled trials. Recently, there have been some targeted therapies using uniform primary endpoints for outcome assessment. Objective: Recommendations can be provided on selecting biologics and targeted synthetic small molecules for refractory HS by comparing the efficacy and safety of these medications. Methods: Databases including ClinicalTrial.gov, Cochrane Library, and PubMed were searched. Randomized controlled trials (RCTs) for moderate-to-severe HS were eligible. We performed random-effect network meta-analysis and ranking probability. The primary outcome was Hidradenitis Suppurativa Clinical Response (HiSCR) at 12-16 weeks. Secondary outcome included Dermatology Life Quality Index (DLQI) 0/1, mean change of DLQI from baseline, and adverse effects. Results: A total of 12 RCTs involving 2915 patients were identified. Adalimumab, bimekizumab, secukinumab 300 mg q4w and secukinumab 300 mg q2w showed superiority to placebo in HiSCR at weeks 12 to 16. In addition, there was no significant difference between bimekizumab and adalimumab as measured by HiSCR (RR = 1.00; 95% CI: 0.66-1.52) and DLQI 0/1 (RR = 2.40, 95% CI: 0.88-6.50). In terms of ranking probability for achieving HiSCR at 12-16 weeks, adalimumab ranked first, followed by bimekizumab, secukinumab 300 mg q4w, and secukinumab 300 mg q2w. All biologics and small molecules did not differ in the development of adverse effects compared to placebo. Conclusions: Adalimumab, bimekizumab, secukinumab 300 mg q4w and secukinumab 300 mg q2w represent four regimens that produce better outcomes than placebo without increased risk of adverse events. Adalimumab and bimekizumab exhibited best HiSCR and DLQI 0/1 between weeks 12-16.

Satisfaction with Life and Coping Strategies among Patients with Hidradenitis Suppurativa: A Cross-Sectional Study

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic recurrent inflammatory dermatosis with vast psychosocial burden. The objective of this study is to thoroughly analyze satisfaction with life (SWL) and coping strategies of HS patients in relation to the clinical and psychosocial factors.

METHODS

114 HS patients (53.1% females; mean age 36.6 ± 13.1 years) were enrolled. Severity of the disease was measured using Hurley staging and International HS Score System (IHS4). Instruments utilized: Satisfaction with Life Scale (SWLS); Coping-Orientation to Problems-Experienced Inventory (Brief COPE); HS Quality of Life Scale (HiSQoL); Patient Health Questionnaire-9 (PHQ-9); Generalized Anxiety Disorder-7 (GAD-7); General Health Questionnaire (GHQ-28).

RESULTS

SWL was low in 31.6% of HS patients. No relation was found between SWL and Hurley staging and IHS4. SWL correlated with GHQ-28 (r = -0.579 p < 0.001), PHQ-9 (r = -0.603 p < 0.001), GAD-7 (r = -0.579 p < 0.001), and HiSQoL (r = -0.449 p < 0.001). Problem-focused coping strategies were most commonly used, followed by emotion-focused coping and avoiding coping strategies. Significant differences were found between the following coping strategies and SWL: self-distraction (p = 0.013), behavioral-disengagement (p = 0.001), denial (p = 0.003), venting (p = 0.019), and self-blame (p = 0.001).

CONCLUSIONS

HS patients present low SWL which correlates with psychosocial burden. Reducing anxiety-depression comorbidity and encouraging optimal coping strategies may be of great importance in holistic approach to HS patients.

Autoinflammation in Syndromic Hidradenitis Suppurativa: The Role of AIM2

BACKGROUND

AIM2 is a key cytoplasmatic pathogen-sensor that detects foreign DNA from viruses and bacteria; it can also recognize damaged or anomalous presence of DNA, promoting inflammasome assembly and activation with the secretion of IL-1β, thus sustaining a chronic inflammatory state, potentially leading to the onset of autoinflammatory skin diseases. Given the implication of the IL-1β pathway in the pathogenesis of syndromic hidradenitis suppurativa (HS), an autoinflammatory immune-mediated skin condition, the potential involvement of AIM2 was investigated.

METHODS

Sequencing of the whole coding region of the AIM2 gene, comprising 5'- and 3' UTR and a region upstream of the first exon of ~800 bp was performed in twelve syndromic HS patients.

RESULTS

Six out of twelve syndromic HS patients carried a heterozygous variant c.-208 A ≥ C (rs41264459), located on the promoter region of the AIM2 gene, with a minor allele frequency of 0.25, which is much higher than that reported in 1000 G and GnomAD (0.075 and 0.094, respectively). The same variant was found at a lower allelic frequency in sporadic HS and isolated pyoderma gangrenosum (PG) (0.125 and 0.065, respectively).

CONCLUSION

Our data suggest that this variant might play a role in susceptibility to develop syndromic forms of HS but not to progress to sporadic HS and PG. Furthermore, epigenetic and/or somatic variations could affect AIM2 expression leading to different, context-dependent responses.

Discovering KYNU as a feature gene in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin condition characterized by nodules, abscesses, and fistulae in skin folds. The underlying pathogenesis of HS remains unclear, and effective therapeutic drugs are limited.

METHODS

We acquired mRNA expression profiles from the Gene Expression Omnibus (GEO) database and conducted differential expression analysis between control and HS samples using R software. Four machine learning algorithms (SVM, RF, ANN, and lasso) and WCGNA were utilized to identify feature genes. GO, KEGG, Metascape, and GSVA were utilized for the enrichment analysis. CIBERSORT and ssGSEA were employed to analyze immune infiltration.

RESULTS

A total of 29 DEGs were identified, with the majority showing up-regulation in HS. Enrichment analysis revealed their involvement in immune responses and cytokine activities. KEGG analysis highlighted pathways such as IL-17 signaling, rheumatoid arthritis, and TNF signaling in HS. Immune infiltration analysis revealed the predominant presence of neutrophils, monocytes, and CD8 T cells. Machine learning algorithms and WCGNA identified KYNU as a feature gene associated with HS. We have also identified 59 potential drugs for HS based on the DEGs. Additionally, ceRNA network analysis identified the MUC19_hsa-miR-382-5p_KYNU pathway as a potential regulatory pathway.

CONCLUSIONS

KYNU emerged as a feature gene associated with HS, and the ceRNA network analysis identified the MUC19_hsa-miR-382-5p_KYNU pathway as a potential regulator.

A rare loss-of-function genetic mutation suggest a role of dermcidin deficiency in hidradenitis suppurativa pathogenesis

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with a multifactorial aetiology that involves a strict interplay between genetic factors, immune dysregulation and lifestyle. Familial forms represent around 40% of total HS cases and show an autosomal dominant mode of inheritance of the disease. In this study, we conducted a whole-exome sequence analysis on an Italian family of 4 members encompassing a vertical transmission of HS. Focusing on rare damaging variants, we identified a rare insertion of one nucleotide (c.225dupA:p.A76Sfs*21) in the DCD gene encoding for the antimicrobial peptide dermcidin (DCD) that was shared by the proband, his affected father and his 11-years old daughter. Since several transcriptome studies have shown a significantly decreased expression of DCD in HS skin, we hypothesised that the identified frameshift insertion was a loss-of-function mutation that might be associated with HS susceptibility in this family. We thus confirmed by mass spectrometry that DCD levels were diminished in the affected members and showed that the antimicrobial activity of a synthetic DCD peptide resulting from the frameshift mutation was impaired. In order to define the consequences related to a decrease in DCD activity, skin microbiome analyses of different body sites were performed by comparing DCD mutant and wild type samples, and results highlighted significant differences between the groins of mutated and wild type groups. Starting from genetic analysis conducted on an HS family, our findings showed, confirming previous transcriptome results, the potential role of the antimicrobial DCD peptide as an actor playing a crucial part in the etio-pathogenesis of HS and in the maintenance of the skin's physiological microbiome composition; so, we can hypothesise that DCD could be used as a novel target for personalised therapeutic approach.