Increased serum tumour necrosis factor-alpha in hidradenitis suppurativa patients: is there a basis for treatment with anti-tumour necrosis factor-alpha agents?

Activated and Naïve Allogenic Human Placental Mesenchymal Stromal Cells Exert an Immunomodulatory Effect on Hidradenitis Suppurativa Patient Peripheral Blood Mononuclear Cells

This pilot study aimed to evaluate the immunomodulatory effect of placental mesenchymal stem/stromal cells (MSCs) on peripheral blood mononuclear cells (PBMCs) from patients with hidradenitis suppurativa (HS). Blood samples were collected from 3 healthy and 3 patients with HS. Isolated PBMCs were stained with carboxyfluorescein succinimidyl ester (CFSE) and stimulated with phorbol 12-myristate 13-acetate (PMA)/Ionomycin solution. The PBMCs of patients with HS were co-cultured with naïve MSCs (n-MSCs), activated with tumor necrosis factor (TNF)-α (10 ng/mL) and interferon (IFN)-γ (10 ng/mL) MSCs (a-MSCs), or adalimumab (30 μg/mL). The division index (proliferation inhibition) of PBMCs was analyzed by flow cytometry using the Proliferation Modeling tool after 5 days of coculture. The relative inflammatory gene expression dynamics and cytokine secretion were quantified in triplicate using real-time polymerase chain reaction (PCR) and Luminex assays. PBMCs from the HS control group showed statistically significant increases in interleukin (IL)-6 and IFN-γ cytokine concentrations and IL-17A gene expression when compared with healthy subjects. Statistically significant reduction of the division index was found in the a-MSCs group (P = 0.04). Also, the Luminex assay revealed significantly reduced proinflammatory cytokine concentrations of IL-9 (P = 0.022) and IL-17A (P = 0.022) in the a-MSCs group with the same trend of numerical lowering in n-MSCs group when compared to HS control. The results of real-time PCR revealed a numerical increase in the expression of the IL-1β, IL-36α, and TNF-α genes in both the a-MSCs and n-MSCs groups compared with the HS control. In conclusion, our findings suggest that MSCs can effectively curb PBMCs proliferation and suppress the production of inflammatory cytokines. Moreover, the preactivation of MSCs with IFN-γ and TNF-α before use can enhance their therapeutic effectiveness. Nevertheless, a larger sample size is imperative to validate these results.

Infliximab inhibits TNF-α-dependent activation of the NLRP3/IL-1β pathway in acne inversa

Background

Acne inversa (AI) is a refractory inflammatory skin disease, and TNF-α plays an important role in the pathogenesis of AI. By blocking TNF-α, infliximab (IFX) has been proven to be a promising method.

Objectives

To explore the underlying mechanisms of IFX treatment in AI patients.

Methods

In this research, we integrated transcriptome sequencing data from the samples of our patients with AI and the GEO database. Ex vivo skin culture of AI patients was conducted to evaluate the efficacy of IFX treatment. Animal studies and cell experiments were used to explore the therapeutic effect and mechanism of IFX treatment.

Results

Both TNF-α and NLRP3 inflammasome-related pathways were enriched in skin lesions of AI patients and murine AI models. After IFX treatment, the NLRP3 inflammasome-related pathway was effectively blocked, and the IL-1β level was normalized in ex vivo AI skin explants and murine AI models. Mechanistically, IFX suppressed the NF-κB signaling pathway to lower the expression of NLRP3 and IL-1β in keratinocytes.

Conclusions

IFX treatment alleviated skin lesions in murine AI models and downregulated NLRP3 and IL-1β expression levels by inhibiting the NF-κB signaling pathway, which was helpful for understanding the mechanism of IFX therapy.

Risk of cardiovascular disorders in hidradenitis suppurativa patients: a large-scale, propensity-matched global retrospective cohort study

BACKGROUND

Patients with hidradenitis suppurativa (HS) often suffer from comorbid diabetes, metabolic syndrome, and hyperlipidemia and, therefore, are susceptible to the development of cardiovascular diseases (CVDs). Moreover, systemic inflammation plays a vital role in the development of atherosclerosis. The creation of atherosclerotic plaque is characterized by endothelial dysfunction driven by elevated concentrations of interleukin (IL)-1, IL-6, and IL-18 among others, as well as tumor necrosis factor (TNF) alpha.

METHODS

This study aimed to assess the risk of HS patients developing CVDs. We performed a large-scale, propensity-matched global retrospective cohort study analyzing the risk of development of CVDs in patients suffering from HS. The analysis included 144,100 HS patients with 144,100 healthy controls (HC). The cohorts were matched regarding demographics and history of diseases relevant to CVDs, e.g., diabetes, obesity, and nicotine dependence. A total of 90 cardiovascular disorders were identified. The identification of cardiovascular disorders was based on ≥1% appearance of the event, based on absolute numbers, in both cohorts.

RESULTS

Before the matching, HS patients displayed a higher frequency in excess weight or obesity (25 vs. 14.4%, respectively), nicotine dependence, and diabetes mellitus, but lower odds of primary hypertension in comparison to healthy controls. A total of 47 CVDs are associated with an increased risk of onset in HS patients. Although the highest hazard ratio (HR; 2.1; 95% CI: 1.95-2.269) was found for unspecified heart failure, the HS cohort was exceptionally predisposed to developing myocardial infarction (HR: 2.06; 95% CI: 1.88-2.27) and an acute embolism and deep vein thrombosis of the lower extremity (HR: 1.93; 95% CI: 1.74-2.14).

CONCLUSIONS

This is the most extensive study on the association of HS with CVDs. We demonstrated that HS patients are at significantly greater risk of developing various CVDs compared to matched controls, with heart failure being the most common one.

The use of biologics and JAK inhibitors in the management of moderate to severe Hidradenitis Suppurativa treatment: a scoping review

This scoping review aims to characterize the use of biologics and Janus Kinase inhibitors (JAKi) in the treatment of Hidradenitis Suppurativa (HS), which is a chronic inflammatory condition. A comprehensive literature search was conducted in PubMed/NCBI, Embase, Web of Science databases, and the Clinicaltrials.gov register. The search included interventional trials assessing the use of biologics or JAKi in HS, with no geographic or time restrictions. Secukinumab and adalimumab were identified as the only two drugs approved by the FDA for treating moderate to severe HS in adults. Several other drug classes showed promising results based on clinical studies reviewed. IL-12/23 inhibitor ustekinumab demonstrated improvements in disease severity scores and HiSCR rates in small trials. IL-17 inhibitors such as brodalumab, bimekizumab, and CJM112 showed preliminary positive responses in early-phase clinical studies and case reports. While evidence was mixed, some TNF-α inhibitors such as infliximab provided benefits according to a randomized controlled trial, though etanercept trials yielded non-significant or inconsistent findings. Larger, well-designed studies are required to further establish their efficacy and safety, but biologics and JAKis show potential as alternative treatment options for moderate to severe HS. The findings of this review contribute to the growing interest among patients and to enhancing the understanding of physician's regarding potential alternative therapeutic options for HS and provide a basis for further research in this field.

The mind-skin connection: A narrative review exploring the link between inflammatory skin diseases and psychological stress

Inflammatory skin diseases are known to negatively impact patient psychology, with individuals experiencing higher rates of stress and subsequent diminished quality of life, as well as mental health issues including anxiety and depression. Moreover, increased psychological stress has been found to exacerbate existing inflammatory skin diseases. The association between inflammatory skin diseases and psychological stress is a timely topic, and a framework to better understand the relationship between the two that integrates available literature is needed. In this narrative review article, we discuss potential neurobiological mechanisms behind psychological stress due to inflammatory skin diseases, focusing mainly on proinflammatory cytokines in the circulating system (the brain-gut-skin communications) and the default mode network in the brain. We also discuss potential descending pathways from the brain that lead to aggravation of inflammatory skin diseases due to psychological stress, including the central and peripheral hypothalamic-pituitary-adrenal axes, peripheral nerves and the skin barrier function.

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.

Tape strips detect molecular alterations and cutaneous biomarkers in skin of patients with hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) has a high unmet need for better treatments. Biopsies are considered the gold standard for studying molecular alterations in skin. A reproducible, minimally invasive approach is needed for longitudinal monitoring in trials and in pediatric populations.

OBJECTIVE

To determine whether skin tape strips can detect molecular alterations in HS and identify biomarkers of disease activity.

METHODS

We performed RNA sequencing on tape strips collected from lesional and healthy-appearing (nonlesional) HS skin (n = 22) and healthy controls (n = 21). We correlated the expression of skin biomarkers between tape strips and a previously published gene-signature of HS biopsies.

RESULTS

Tape strips detected upregulation of known HS biomarkers (eg, Interleukin[IL]-17A) in nonlesional and/or lesional skin and also identified novel clinically actionable targets, including OX40 and JAK3. The expression of Th17 and tumor necrosis factor-α pathways were highly correlated between tape strips and biopsies. HS clinical severity was significantly associated with expression of biomarkers (eg tumor necrosis factor-α , IL-17 A/F, OX40, JAK1-3, IL-4R) in HS lesional and/or nonlesional skin.

LIMITATIONS

Sample size. Tape stripping is limited in depth.

CONCLUSION

This study validates tape strips as a minimally-invasive approach to identify cutaneous biomarkers in HS. This provides a novel avenue for monitoring treatment efficacy and a potential step toward individualized therapy in HS.

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.

New treatment of pyoderma gangrenosum and hidradenitis suppurativa: A review

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

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.

Secukinumab in the treatment of hidradenitis suppurativa

The IL-17 pathways are involved in the pathophysiology of many inflammatory skin conditions, including hidradenitis suppurativa. Secukinumab, an IL-17A inhibitor, has been used for years in inflammatory skin disorders such as psoriasis. To date, the only US FDA-approved medication for hidradenitis suppurativa is adalimumab, a TNF-α inhibitor. Recently, secukinumab has demonstrated promising results in the treatment of hidradenitis suppurativa in the phase III SUNSHINE and SUNRISE clinical trials. This article reviews the mechanism of action of secukinumab and summarizes the available clinical efficacy and safety data regarding secukinumab in the management of hidradenitis suppurativa.

Real-world safety and effectiveness of adalimumab in patients with hidradenitis suppurativa: A 52-week analysis of a postmarketing surveillance study in Japan

Adalimumab is a human monoclonal antibody against tumor necrosis factor-α that was approved in Japan for the treatment of hidradenitis suppurativa (HS), a chronic recurrent inflammatory skin disease. We report the results of the final analysis of the postmarketing surveillance (PMS) study (ClinicalTrials.gov: NCT03894956), which evaluated the 52-week safety and efficacy of adalimumab for HS treatment in real-world clinical practice in Japan. This multicenter, prospective, open-label, observational study (March 2019 to May 2021) included patients with HS treated with subcutaneous adalimumab at doses following the package insert. The primary endpoint was safety, and the secondary endpoints were effectiveness, including HS clinical response (HiSCR), C-reactive protein (CRP), skin pain, and Dermatology Life Quality Index (DLQI). Of the 84 patients registered at 65 sites, 83 patients were included in the analyses. Adverse drug reactions (ADRs) were reported by 10 (12.0%) patients; two patients reported a serious ADR, including one patient with serious infection. Other safety events of special interest reported were liver disorder and dermatitis psoriasiform (one patient each). Almost all patients with ADRs were recovering or had recovered, except for one patient who experienced a serious ADR of liver disorder and died. At 12 weeks, 55.4% of patients achieved HiSCR; this increased to 60.5% and 62.8% at 24 and 52 weeks of adalimumab treatment, respectively. Significant reductions from baseline in CRP (P < 0.05), skin pain (P < 0.0001), and DLQI (P < 0.0001) were observed at all time points. The results from this PMS study demonstrated that long-term adalimumab treatment is well tolerated and effective in patients with HS in real-world clinical practice in Japan.

Obstacles to Early Diagnosis and Treatment of Hidradenitis Suppurativa: Current Perspectives on Improving Clinical Management

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that can progress to significant tunnels and scars that affect quality of life, especially if diagnosis and treatment are delayed. Average delay after initial presentation of HS symptoms can range from 3 to 10 years in adults and 1 to 2 years in children. Factors associated with diagnostic delay include female gender, non-white race, and greater disease severity at diagnosis. Contributing factors include misdiagnoses, difficulty accessing a dermatologist, hesitation in seeking care due to the stigmatizing nature of the disease, and lack of awareness among providers and patients. While efforts to increase awareness include academic talks at conferences and by foundations geared toward HS, social media offers the opportunity to reach young audiences. Many patients report dissatisfaction with their HS treatments. Better understanding of HS pathophysiology and implementation of clinically focused phenotypes and endotypes can lead to development of more targeted and efficacious therapies. FDA approval of medications for HS beyond adalimumab will increase access to a wider selection of therapies, and implementation of therapeutic drug monitoring may maximize the use of biologics for HS.

Emerging Treatments and the Clinical Trial Landscape for Hidradenitis Suppurativa Part I: Topical and Systemic Medical Therapies

Hidradenitis suppurativa (HS) is an oftentimes debilitating condition that presents with painful nodules, abscesses, and sinus tracts. This condition is challenging to treat, in part because the pathogenesis of the condition is incompletely understood but also because there are limited therapeutic options. HS research is undergoing explosive growth with multiple new molecular pathways under study, which will hopefully lead to improved disease control for patients. Part I of this review will provide an overview of the emerging topical and systemic therapies under investigation for HS.

New Insight into the Molecular Pathomechanism and Immunomodulatory Treatments of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is an immune-mediated inflammatory disorder characterized by deep-seated nodules, abscesses, sinus tracts and scars localized in the intertriginous areas. It is accompanied by pain, malodourous secretion and a dramatically decreased quality of life. Although the pathogenesis has not been entirely elucidated, the primary event is follicular hyperkeratosis of the pilosebaceous apocrine unit. Since the registration of the tumor necrosis factor-alpha inhibitor Adalimumab in 2015, several cytokines have been implicated in the pathomechanism of HS and the research of novel therapeutic targets has been intensified. We provide an update on the inflammatory cytokines with a central role in HS pathogenesis and the most promising target molecules of future HS management.

Coexistence of pachyonychia congenita and hidradenitis suppurativa: more than a coincidence

BACKGROUND

The coexistence of pachyonychia congenita (PC) and hidradenitis suppurativa (HS) has been described in case reports. However, the pathomechanism underlying this association and its true prevalence are unknown.

OBJECTIVES

To determine the genetic defect underlying the coexistence of PC and HS in a large kindred, to delineate a pathophysiological signalling defect jointly leading to both phenotypes, and to estimate the prevalence of HS in PC.

METHODS

We used direct sequencing and a NOTCH luciferase reporter assay to characterize the pathophysiological basis of the familial coexistence of HS and PC. A questionnaire was distributed to patients with PC registered with the International Pachyonychia Congenita Research Registry (IPCRR) to assess the prevalence of HS among patients with PC.

RESULTS

Direct sequencing of DNA samples obtained from family members displaying both PC and HS demonstrated a missense variant (c.275A>G) in KRT17, encoding keratin 17. Abnormal NOTCH signalling has been suggested to contribute to HS pathogenesis. Accordingly, the KRT17 c.275A>G variant resulted in a significant decrease in NOTCH activity. To ascertain the clinical importance of the association of HS with PC, we distributed a questionnaire to all patients with PC registered with the IPCRR. Seventy-two of 278 responders reported HS-associated clinical features (25·9%). Disease-causing mutations in KRT17 were most prevalent among patients with a dual phenotype of PC and HS (43%).

CONCLUSIONS

The coexistence of HS and KRT17-associated PC is more common than previously thought. Impaired NOTCH signalling as a result of KRT17 mutations may predispose patients with PC to HS. What is already known about this topic? The coexistence of pachyonychia congenita (PC) and hidradenitis suppurativa (HS) has been described in case reports. However, the pathomechanism underlying this association and its true prevalence are unknown. What does this study add? A dual phenotype consisting of PC and HS was found to be associated with a pathogenic variant in KRT17. This variant was found to affect NOTCH signalling, which has been previously implicated in HS pathogenesis. HS was found to be associated with PC in a large cohort of patients with PC, especially in patients carrying KRT17 variants, suggesting that KRT17 variants causing PC may also predispose to HS. What is the translational message? These findings suggest that patients with PC have a higher prevalence of HS than previously thought, and hence physicians should have a higher level of suspicion of HS diagnosis in patients with PC.

Advances in biologic and small molecule therapies for hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disorder characterized by painful nodules, abscesses, fistulae, and scarring with a predilection for flexural regions. Several biologics and small molecule inhibitors are being evaluated in clinical trials for treatment.

AREAS COVERED

The authors discuss the data available from clinical trials and smaller, high-quality studies for existing and emerging biologic and small molecule inhibitor therapies for treatment of HS. Biologics discussed include TNFα, IL-17, IL-23, IL-12/23, and IL-1 inhibitors. Small molecule inhibitors discussed include PDE4, JAK, TYK, IFX-1, and complement cascade inhibitors. Pharmacokinetics and pharmacodynamics for these drugs are also described.

EXPERT OPINION

Trial data and our own experience have shown that about half of HS patients experience improvement with adalimumab. However, there is a significant need for pharmacotherapies with higher efficacy goals as in those used for psoriasis. Many biologics and small molecule inhibitors are being tested in clinical trials. The landscape of upcoming therapies for hidradenitis suppurativa appears promising.

Radiation therapy in chronic hidradenitis suppurativa: case report

A 26-year-old female presented recurrent painful, carbuncles at both axillae for 10 years. It caused offensive odor and scar. Tissue diagnosis was chronic hidradenitis suppurativa. She was treated using antibiotics followed by multiple excisions with drainage but showed no improvement. Isotretinoin provided no benefit. She was socially isolated and experienced lower quality of life. Consequently, she was sent for radiation therapy. Computed tomography simulation was performed revealing an ulcer with deep chronic pus tracts at her axilla. Three-dimensional conformal radiation therapy was provided with 6 MV photon (7.5 Gy in 3 fractions) covering all ulcers and pus tracts. On the last day of radiation therapy, carbuncles and wounds at the left axilla exhibited much improvement without pus. Three months follow-up showed much improvement of the lesions. The skin was smoother without pus or odor. Radiation therapy was confirmed one treatment option for chronic hidradenitis suppurativa.

Paradoxical Hidradenitis Suppurativa during Biologic Therapy, an Emerging Challenge: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease usually occurring after puberty with painful, deep-seated, inflammatory lesions in the apocrine gland-bearing areas of the body. Although HS pathogenesis is still unproven, recent major research advantages have increased our knowledge of the mechanisms behind HS lesions. Particularly, follicular occlusion followed by follicular rupture has been shown to be crucial to HS development, leading to immune response activation, and resulting in typical clinical HS lesions. Moreover, an increased and imbalanced cytokine production, such as interleukin (IL) 17 and tumor necrosis factor (TNF) α, may play a role in HS. In recent years, paradoxical adverse events have been described during treatment. Since the recent increased use of biologic treatments in HS, an increased number of paradoxical HS occurrences have been reported. In this review, we analyzed all current data on paradoxical HS triggered by biological drugs.

Janus kinase 1 inhibitor INCB054707 for patients with moderate-to-severe hidradenitis suppurativa: results from two phase 2 studies

Background

Janus kinase (JAK)‐mediated cytokine signalling contributes to local and systemic inflammation in hidradenitis suppurativa (HS).

Objectives

To describe the safety and efficacy results from two multicentre phase II trials of the JAK1 inhibitor INCB054707 in patients with moderate‐to‐severe HS.

Methods

Patients received open‐label INCB054707 15 mg once daily (QD; Study 1) or were randomized to INCB054707 30, 60 or 90 mg QD or placebo (3 : 1 within each cohort; Study 2) for 8 weeks. Eligible patients were aged 18–75 years and had moderate‐to‐severe HS (Hurley stage II/III disease), lesions present in at least two anatomical locations, and a total abscess and inflammatory nodule count ≥ 3. The primary endpoint for both studies was safety and tolerability. Secondary endpoints included HS Clinical Response (HiSCR) and other efficacy measures.

Results

Ten patients were enrolled in Study 1 (15 mg INCB054707) and 35 in Study 2 (INCB054707: 30 mg, n = 9; 60 mg, n = 9; 90 mg, n = 8; placebo, n = 9). Overall, 70% of patients in Study 1 and 81% of patients receiving INCB054707 in Study 2 experienced at least one treatment‐emergent adverse event; 30% and 42% of patients, respectively, had at least one treatment‐related adverse event. Among the evaluable patients, three (43%) in Study 1 and 17 (65% overall: 30 mg, 56%; 60 mg, 56%; 90 mg, 88%) receiving INCB054707 vs. 4 patients (57%) receiving placebo in Study 2 achieved HiSCR at week 8.

Conclusions

INCB054707 was well tolerated, with responses observed in patients with moderate‐to‐severe HS. The safety and efficacy findings from these studies demonstrate proof of concept for JAK1 inhibition in HS. The studies are registered on ClinicalTrials.gov (NCT03569371 and NCT03607487).

Hidradenitis suppurativa: Disease pathophysiology and sex hormones

Hidradenitis suppurativa is a cutaneous chronic inflammatory disease that is estimated to affect about 1% of the population and caused pain, malodorous discharge, disfigurement, and poor quality of life with psychosocial problems. The typical features are recurrent painful nodules, abscesses, and sinus tracts on the axillae, groins, gluteal areas, and anogenital regions since postpuberty. Smoking and obesity are two major triggering factors of hidradenitis suppurativa. Women are prone to have hidradenitis suppurativa than men in Western countries, but the male-to-female ratio is reversed in oriental countries. The disease severity can be affected by menstruation, pregnancy, and menopause. Furthermore, the phenotypes are different among men and women with hidradenitis suppurativa. Men are prone to have buttock involvement while women are prone to have axillary, groins, and submammary lesions. This review introduces the skin appendages and pathophysiology of hidradenitis suppurativa and then focuses on the sex difference and the effects of sex hormones on hidradenitis suppurativa and current hormone-associated treatments.

Hidradenitis suppurativa: A folliculotropic disease of innate immune barrier dysfunction?

The innate immune system of human skin consists of a multi-layered barrier consisting of cells and soluble effector molecules charged with maintaining homeostasis and responding to insults and infections. It has become increasingly clear that these barrier layers become compromised in skin diseases, especially in disorders of an (auto)inflammatory nature. In the case of hidradenitis suppurativa, great strides have been made in recent years in characterizing the underlying breakdown in homeostatic innate immunity, including an increasing understanding of the central role of the hair follicle in this process. This breakdown appears to occur at multiple levels: the pilosebaceous unit, associated epithelium, the cutaneous microbiome, alteration of immune cell function and local molecular events such as complement activation. This review seeks to summarize, contextualize and analyse critically our current understanding of how these innate immune barriers become dysregulated in the early stage(s) of hidradenitis suppurativa, and to speculate on where potential hidradenitis suppurativa research could be most fruitful.

Clinical Implementation of Biologics and Small Molecules in the Treatment of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, auto-inflammatory skin disease originating from the hair follicles. The typical inflammatory nodules, abscesses, and draining sinus tracts (tunnels) are characterized by a massive influx of neutrophils, macrophages, B-cells, plasma cells, T helper (Th)1, Th17 cells and upregulation of pro-inflammatory cytokines such as IL-1, IL-17, IL-12/23, and TNF-α. Over the last decades, several clinical trials evaluated the clinical efficacy of different biologics targeting these pro-inflammatory cytokines, in particular TNF-α and IL-1. However, adalimumab is still the only registered drug for HS. This review discusses biologics and small molecules with high level of evidence for their clinical application, provides guidance on when and how to use these biologics and small molecules in clinical practice, and elaborates on the combination with medical and surgical treatment options beyond the current guidelines. Furthermore this review provides an overview of potential biologics and small molecules currently under investigation for novel targets in HS such as IL-36, C5a, Janus kinase family members, CD-40, LTA4 and CXCR1/2.

MCPIP1/Regnase-1 Expression in Keratinocytes of Patients with Hidradenitis Suppurativa: Preliminary Results

The pathogenesis of hidradenitis suppurativa (HS) is yet to be fully understood. However, inflammation is a key element in the development of skin lesions. The aim of this study was to evaluate the expression of monocyte chemotactic protein-1-induced protein-1 (MCPIP1) in the skin of patients suffering from HS. Skin biopsies of 15 patients with HS and 15 healthy controls were obtained and processed for immunohistochemistry, western blot, and real time PCR. The highest mean MCPIP1 mRNA expression was found in the inflammatory lesional skin of HS patients. It was significantly higher than MCPIP1 mRNA expression in the biopsies from both healthy controls and non-lesional skin of HS patients. Western blot analysis indicated that expression of MCPIP1 was elevated within both lesional and non-lesional skin compared to the healthy control. The increased MCPIP1 mRNA and protein expression level in HS lesions may indicate its possible role in the disease pathogenesis.

Prevalence of depression among children, adolescents, and adults with hidradenitis suppurativa

BACKGROUND

Information on prevalence of depression among children, adolescents, and adults with hidradenitis suppurativa (HS) is limited.

OBJECTIVE

To compare prevalence of depression in HS patients with that of controls.

METHODS

Cross-sectional analysis of 38,140 adult and 1162 pediatric HS patients and controls identified using data from electronic health records. Primary outcome was prevalent depression.

RESULTS

Prevalence of depression among adults with HS was 30.0% (95% Confidence interval [CI], 29.6-30.5), compared with 16.9% (95% CI, 16.7-17.1) among controls. Among children and adolescents with HS, prevalence of depression was 11.7% (95% CI, 10.0-13.7), compared with 4.1% (95% CI, 3.6-4.7) among controls. In adjusted analyses, adults and children/adolescents with HS had 1.26 (95% CI, 1.25-1.28; P < .001) and 1.42 (95% CI, 0.999-2.01; P = .051) times the odds of having depression relative to controls, respectively.

LIMITATIONS

We could not evaluate the influence of disease severity on the outcome.

CONCLUSION

Depression is prevalent among children, adolescents, and adults with HS. Periodic screening for depression may be warranted.

Efficacy and safety of adalimumab in hidradenitis suppurativa: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Adalimumab is used as a first-line biologic agent in the management of moderate-to-severe hidradenitis suppurativa (HS). The objective of the present study was to evaluate the efficacy and safety of adalimumab in patients with moderate-to-severe HS.

METHODS

We performed a systematic review and meta-analysis according to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines. Pooled estimates, namely standardized mean difference (SMD) and relative risk (RR), were calculated using random-effect model with trial sequential analysis. Small study effects were examined using the Doi plot. Certainty of evidence (CoE) was assessed using "The Grading of Recommendations Assessment, Development, and Evaluation" approach, and number-needed-to-treat (NNT) was calculated.

RESULTS

Five randomized controlled trials, involving 1014 patients, were included. We performed subgroup analysis of adalimumab administered subcutaneously both weekly and every other week. Adalimumab administered weekly was associated with better clinical response achievement (RR 1.76, 95% confidence interval [95% CI] 1.35-2.29; trial sequential analysis TSA-adjusted CI 1.01-3.08; CoE: low; NNT = 5) and a significant improvement in modified Sartorius score (SMD = -0.45, 95% CI = -0.76 to -0.13; CoE: very low; NNT = 10) and dermatology life quality index (DLQI) (SMD -0.47, 95% CI -0.61 to -0.32; CoE: low; NNT = 10). Nevertheless, adalimumab administered every other week showed an improvement only in modified Sartorius score. The pooled RRs of adverse events in both groups revealed no statistical significance when compared with the placebo.

CONCLUSIONS

Adalimumab administered weekly resulted in not only better clinical responses than placebo but also significantly improved disease severity and quality of life of patients with moderate-to-severe HS. Our study provides supporting evidence to the current guidelines and aids decision-making in the application of adalimumab in HS management.

Serum high-sensitivity C-reactive protein, tumor necrosis factor-α, interleukin (IL)-1β, IL-17A and IL-23 levels in patients with hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, recurrent inflammatory skin disease that leads to scar formation. The immune pathogenesis of HS is not fully understood and inhibitors of tumor necrosis factor (TNF)-α, interleukin (IL)-17, IL-1, IL-23 can be used for treating HS. Identification of serum biomarkers may help understanding individual differences in HS pathogenesis, evaluating disease severity and developing more effective treatment methods.

OBJECTIVES

To assess the serum levels of proinflammatory cytokines TNF-α, IL-1β, IL-17A, IL-23 and high-sensitivity C-reactive protein (hs-CRP) in patients with HS and to evaluate the impact of treatment on cytokine levels.

METHODS

Serum proinflammatory cytokine and hs-CRP levels were measured using enzyme-linked immunosorbent assay kits in 24 healthy controls and in 26 HS patients at baseline and after a 3-month treatment. Patients were treated with clindamycin, adalimumab, dapsone, doxycycline and acitretin, based on HS condition and laboratory results. Control, pre-treatment and post-treatment values were compared.

RESULTS

HS patients had significantly higher hs-CRP levels than controls which decreased following treatment (p = 0,010, p = 0,007). No significant difference was found in serum levels of TNF-α, IL-1β, IL-17A, IL-23 compared to controls and post-treatment levels.

CONCLUSIONS

There is insufficient data to suggest TNF-α, IL-1β, IL-17A and IL-23 as serum biomarkers in HS. hs-CRP can be used as an indicator of treatment response and systemic inflammation.

A safety review of biologic therapies for the management of hidradenitis suppurativa and unmet needs

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disorder characterized by nodules, abscesses, fistulae, and significant scarring in intertriginous areas rich in apocrine glands. Immunomodulator drugs, including biologics, are a mainstay of treatment for this disease.

AREAS COVERED

This review details the safety profiles of various biologic therapies currently available commercially that have been tried for HS as assessed in clinical trials and observational studies. As the only Food and Drug Administration (FDA)-approved medication for the treatment of moderate-to-severe HS, adalimumab is discussed in the most detail. Additional biologic medications, including tumor necrosis factor α (TNFα) inhibitors, interleukin 1 (IL-1) inhibitors, IL-12 and IL-23 inhibitors, IL-17 inhibitors, and IL-23 inhibitors, are discussed as well. Safety concerns in special populations, including pregnant women and children, are outlined.

EXPERT OPINION

Existing data support excellent short-term and long-term safety profiles for adalimumab, although caution must be taken with use in high-risk patient populations, including those with chronic infections or increased risk of malignancy. Based on their safety data for other indications, additional biologic agents appear safe in HS as well. However, further research is needed to fully understand the safety profiles of these medications in the HS population.

Potential predictive biomarkers of adalimumab response in patients with hidradenitis suppurativa

BACKGROUND

Adalimumab provides significant efficacy for patients with hidradenitis suppurativa (HS), which was demonstrated by at least 50% of patients achieving a clinical response by week 12 that was maintained through to week 168 in the PIONEER trials.

OBJECTIVES

To identify whether there are biomarkers that could predict adalimumab response, as well as markers that differentially respond to adalimumab in patients with HS.

METHODS

Baseline and week-12 plasma samples from the PIONEER studies were used to assess the levels of circulating proteins by multiplex and enzyme-linked immunosorbent assays.

RESULTS

Analyses revealed significantly higher high-sensitivity C-reactive protein (hs-CRP) and chemokine (C-C motif) ligand (CCL) 16 (HCC-4) levels in nonresponders at baseline and identified a multivariate response signature of calprotectin, fractalkine and HCC-4, reaching an 86% predictive accuracy rate for adalimumab response. Additionally, post-treatment reduction of plasma C-X-C motif chemokine ligand (CXCL)9, CXCL8 (interleukin-8) and CCL19 (macrophage inflammatory protein 3β) were greater in adalimumab super-responders than in nonresponders (P = 0·026, P = 0·044 and P = 0·026, respectively). These cytokines are involved in the recruitment of innate and adaptive inflammatory cells, and/or stimulation of certain inflammatory responses, suggesting that these pathways could be disease drivers in adalimumab nonresponders.

CONCLUSIONS

These initial results suggest HCC-4, calprotectin and fractalkine could be potential predictive biomarkers of adalimumab response in HS and identified possible tumour necrosis factor-independent disease pathways.

In-Depth Analysis of the Hidradenitis Suppurativa Serum Proteome Identifies Distinct Inflammatory Subtypes

Hidradenitis suppurativa is a chronic inflammatory dermatosis with presentations ranging from painful nodules and abscesses to draining tunnels. Using an unbiased proteomics approach, we assessed cardiovascular-, cardiometabolic-, and inflammation-related biomarkers in the serum of patients with moderate-to-severe hidradenitis suppurativa. The serum of patients with hidradenitis suppurativa clustered separately from that of healthy controls and had an upregulation of neutrophil-related markers (Cathepsin D, IL-17A, CXCL1). Patients with histologically diagnosed dermal tunnels had higher serum lipocalin-2 levels compared with those without tunnels. Consistent with this, patients with tunnels had a more neutrophilic-rich serum signature, marked by Cathepsin D, IL-17A, and IL-17D alterations. There was a significant serum‒skin correlation between proteins in the serum and the corresponding mRNA expression in skin biopsies, with healthy-appearing perilesional skin demonstrating a significant correlation with neutrophil-related proteins in the serum. CSF3 mRNA levels in lesional skin significantly correlated with neutrophil-related proteins in the serum, suggesting that CFS3 in the skin may be a driver of neutrophilic inflammation. Clinical significantly correlated with the levels of lipocalin-2 and IL-17A in the serum. Using an unbiased, large-scale proteomic approach, we demonstrate that hidradenitis suppurativa is a systemic neutrophilic dermatosis, with a specific molecular signature associated with the presence of dermal tunnels.

Association of Birth Weight, Childhood Body Mass Index, and Height With Risk of Hidradenitis Suppurativa

Importance

There is a lack of evidence on the association of birth weight, childhood body mass index (BMI), change in BMI during childhood, and childhood height with subsequent risks of hidradenitis suppurativa (HS) in adulthood.

Objective

To investigate the association of birth weight, childhood BMI, change in BMI during childhood, and childhood height with subsequent risks of HS in adulthood in a large Danish population-based cohort.

Design, Setting, and Participants

This cohort study included 347 200 schoolchildren from the Copenhagen School Health Records Register born from 1930 to 1996 who were linked to the Danish National Patient Register of hospital discharge diagnoses to identify cases of HS. Birth weight was reported by parents or guardians, whereas childhood weight and height were measured by school physicians or nurses at ages 7 through 13 years. Cox proportional hazards regressions were used to estimate hazard ratios (HRs) and 95% CIs. Statistical analysis was performed from February 20, 2019, to May 15, 2019.

Main Outcomes and Measures

A diagnosis of HS as recorded in the Danish National Patient Register.

Results

Among the 347 200 children included in the study (175 750 boys) during the follow-up period from 1977 to 2017, 1037 individuals (677 females; median age at diagnosis, 39 years [range, 15-73 years]) received a diagnosis of HS. A nonlinear (U-shaped) association was found between birth weight and HS, such that both the lightest (2.00-2.75 kg; HR, 1.36 [95% CI, 1.10-1.68]) and the heaviest babies (4.26-5.50 kg; HR, 1.39 [95% CI, 1.01-1.93]) had increased risks of HS compared with normal-weight babies (3.26-3.75 kg; P = .04 for deviation from linearity). The risk of HS increased significantly with increasing BMI z score at each age from 7 to 13 years, from an HR of 1.32 (95% CI, 1.24-1.40) per BMI z score at 7 years of age to an HR of 1.50 (95% CI, 1.40-1.61) per BMI z score at 13 years of age. Compared with children with a normal weight at 7 and 13 years of age, those with a normal weight at 7 years of age and overweight at 13 years of age had a significantly increased risk of HS (HR, 2.11 [95% CI, 1.63-2.74]) and children with persistent overweight at both ages also had an increased risk of HS (HR, 2.61 [95% CI, 2.02-3.38]). Children with overweight at 7 years of age but with normal weight at 13 years of age did not have a significantly increased risk of HS (HR, 1.05 [95% CI, 0.67-1.67]). Childhood height at all ages was not associated with risk of HS (children at 7 years had an HR of 1.00 [95% CI, 0.94-1.07], and those 13 years had an HR of 1.06 [95% CI, 0.99-1.13], per z score).

Conclusions and Relevance

This cohort study found that both the lightest and heaviest babies had increased risks of HS. Childhood BMI was positively and significantly associated with risk of HS development in adulthood. These findings suggest that returning to normal weight before puberty reduces risks of HS to levels observed in children who were never overweight. Childhood height was not associated with risk of HS.

A Systematic Review of Promising Therapeutic Targets in Hidradenitis Suppurativa: A Critical Evaluation of Mechanistic and Clinical Relevance

This systematic review identifies and critically evaluates the mechanistic and clinical evidence of new promising therapeutic targets in hidradenitis suppurativa (HS). Evidence for these targets is largely based on observational data with limited ex vivo and translational data from clinical trials. A number of placebo-controlled studies have been completed or are underway utilizing IL-1, IL-23, IL-17, complement, and Jak inhibition, although there is concern regarding elevated placebo response rates and the questionable validity of clinical scores in some participant subsets. Knowledge gaps are identified suggesting a direction for future mechanistic studies in HS, including more comprehensive inflammatory endotype profiling of disease.

Hidradenitis suppurativa is associated with hypothyroidism and hyperthyroidism: a large-scale population-based study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory disease involving the skin bearing apocrine glands. There are numerous comorbidities and associated diseases among patients with HS. The association of HS and thyroid abnormalities is equivocal. We aimed to explore whether HS is associated with thyroid disorders.

METHODS

In this cross-sectional large-scale population-based study in Israel, patients with a validated diagnosis of HS were matched at a proportion of 1:5 with age- and gender-matched healthy controls without HS. A cross-checking for HS diagnosis by International Classification of Diseases, ninth revision (ICD-9) coding, and hyperthyroidism and hypothyroidism by ICD-9 coding was performed. Demographic and exposure covariates were identified. Univariate and multivariate logistic regressions were utilized to establish the association of HS with thyroid disorders.

RESULTS

Study participants included 4,191 HS patients and 20,941 controls. The average age of patients was 39.7 years old, and 61.8% were female. 53.4% of HS patients and 13.5% of controls (P < 0.001) were smokers. Odds ratios (ORs) for hypothyroidism and hyperthyroidism in HS were 2.91 (95% confidence interval [CI] 2.48-3.40) and 2.25 (95% CI 1.55-3.28), respectively (P < 0.001 for both). While the association of HS with hypothyroidism was maintained across genders and all age groups, and remained positive after controlling for smoking status, the association with hyperthyroidism remained positive only among females, middle-aged patients, and nonsmokers.

CONCLUSION

HS is independently associated with hypothyroidism. The association of HS with hyperthyroidism held significance only in limited subgroups. Smoking status is a major modifier, mainly in the association of HS with hyperthyroidism.

Incidence of Myocardial Infarction and Cerebrovascular Accident in Patients With Hidradenitis Suppurativa

Importance

Although hidradenitis suppurativa (HS) is associated with several cardiovascular risk mediators, information on the risk of myocardial infarction (MI) and cerebrovascular accident (CVA) in this population is sparse.

Objective

To compare risk of MI, CVA, and composite disease (MI or CVA) in patients with HS, stratified by use of biologic agents, with controls without HS.

Design, Setting, and Participants

A retrospective cohort analysis was conducted between January 1, 1999, and April 1, 2019, using a demographically heterogeneous population-based sample of over 56 million unique patients. Individuals with HS (n = 49 862) and without HS (n = 1 421 223) were identified using electronic health records data.

Main Outcomes and Measures

The primary outcome was incidence of composite MI or CVA.

Results

Of the 49 862 patients with HS, 37 981 were women (76.2%), 29 711 were white (59.6%), and mean (SD) age was 38.3 (13.3) years. Crude incidence rate of composite disease was 6.6 (95% CI, 6.3-7.0) per 1000 person-years in patients with HS compared with 6.8 (95% CI, 6.7-6.8) per 1000 person-years in controls. In patients with HS, crude incidence rates were 2.9 (95% CI, 2.6-3.1) per 1000 person-years for MI alone and 4.1 (95% CI, 3.9-4.4) per 1000 person-years for CVA alone compared with 3.2 (95% CI, 3.18-3.25) per 1000 person-years for MI alone in control patients and 4.1 (95% CI, 4.0-4.1) per 1000 person-years for CVA alone in control patients. In adjusted analysis, patients with HS had a 23% increased risk of composite disease (hazard ratio [HR], 1.23; 95% CI, 1.17-1.30; P < .001) and a similar increase in the risk of MI alone (HR, 1.21; 95% CI, 1.12-1.32; P < .001) and CVA alone (HR, 1.22; 95% CI, 1.14-1.31; P < .001) compared with control patients. The relative difference in composite MI or CVA risk between patients with HS and controls was highest among younger patients HR in subgroup aged 18-29 years: 1.67; 95% CI, 1.37-2.03).

Conclusions and Relevance

Patients with HS appear to have an increased risk of MI and CVA. Early management of modifiable cardiovascular risk mediators may be warranted in patients with HS.

Intralesional Triamcinolone May Not Be Beneficial for Treating Acute Hidradenitis Suppurativa Lesions: A Double-Blind, Randomized, Placebo-Controlled Trial

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory condition characterized by recurrent nodules, sinus tracts, comedones, and scarring. Hidradenitis suppurativa is often associated with pain and decreased quality of life. Limited clinical trial data exist regarding the management of acute HS lesions, but clinical experience and a prospective case series suggest that intralesional triamcinolone may be useful.

OBJECTIVE

To compare the efficacy of intralesional triamcinolone to placebo for the treatment of HS inflammatory lesions.

MATERIALS AND METHODS

This is a double-blind, randomized, placebo-controlled trial comparing intralesional triamcinolone 10 mg/mL, triamcinolone 40 mg/mL, and normal saline (NS). Thirty-two subjects at University of North Carolina Dermatology and Skin Cancer Centers were enrolled for a total of 67 lesions. Subjects reported pain scores, days to resolution, and satisfaction on a standardized survey over a 14-day period.

RESULTS

When intralesional injections of triamcinolone 10 mg/mL, triamcinolone 40 mg/mL, and NS were compared, no significant difference was found for days to HS inflammatory lesion clearance, pain reduction at Day 5, or patient satisfaction.

CONCLUSION

No statistically significant difference was found between varying concentrations of triamcinolone and NS for the treatment of HS lesions. Steroid injections may be less effective for the management of acute HS than typically presumed.

Aetiology and pathogenesis of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder. Patients develop inflamed nodules and abscesses and, at later stages of disease, epithelialized tunnels and scars in skinfolds of axillary, inguinal, gluteal and perianal areas. Quality of life is affected due to severe pain, purulent secretion, restricted mobility and systemic involvement. Genetics and lifestyle factors including smoking and obesity contribute to the development of HS. These factors lead to microbiome alteration, subclinical inflammation around the terminal hair follicles, and infundibular hyperkeratosis, resulting in plugging and rupture of the follicles. Cell-damage-associated molecules and propagating bacteria trigger inflammation and lead to massive immune cell infiltration that clinically manifests as inflamed nodules and abscesses. The immune system plays a key role also in the progression and chronification of skin alterations. Innate proinflammatory cytokines (e.g. interleukin-1β and tumour necrosis factor-α), mediators of activated T helper (Th)1 and Th17 cells (e.g. interleukin-17 and interferon-γ), and effector mechanisms of neutrophilic granulocytes, macrophages and plasma cells are involved. Simultaneously, skin lesions contain anti-inflammatory mediators (e.g. interleukin-10) and show limited activity of Th22 and regulatory T cells. The inflammatory vicious circle finally results in pain, purulence, tissue destruction and scarring. Chronic inflammation in patients with HS is also frequently detected in organs other than the skin, as indicated by their comorbidities. All these aspects represent a challenge for the development of therapeutic approaches, which are urgently needed for this debilitating disease. This scholarly review focuses on the causes and pathogenetic mechanisms of HS and the potential therapeutic value of this knowledge.

Metabolic, pharmacokinetic, and toxicological issues of biologic therapies currently used in the treatment of hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa is a chronic, relapsing, debilitating inflammatory dermatologic disease of the terminal hair follicles at intertriginous sites clinically characterized by painful inflammatory nodules, abscesses, draining sinus tracts, and dermal fibrosis. The management of hidradenitis suppurativa is a challenge and usually consists of both medical and surgical approaches, which must often be combined for best outcome. The introduction of biological therapies, specifically TNFα-inhibitors such as adalimumab, has profoundly changed the therapeutic armamentarium of the disease.

AREAS COVERED

The PubMed database was searched using combinations of the following keywords: hidradentis suppurativa, biologic therapy, TNF-α inhibitors, adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, adverse effects, pharmacodynamics, pharmacology, adverse events, pharmacokinetics, drug interaction. This article reviews and updates the chemistry, pharmacokinetics, mechanism of action, adverse effects, drug interactions of on-label and off-label use of TNF-α inhibitors in HS.

EXPERT OPINION

Biologic agents, particularly adalimumab, exhibit clinical efficacy in patients with hidradenitis suppurativa. Careful patient selection and close monitoring during treatment are mandatory to provide safe and effective use of the TNF-α inhibitor. Familiarity with biologic agents is crucial because these agents could become a consolidated treatment option in the clinician's therapeutic approaches.

Hidradenitis Suppurativa as a Paradoxical Side Effect to the Use of Adalimumab in Patients with Crohn's Disease?

Background

Hidradenitis suppurativa is a chronic inflammatory skin disorder associated with inflammatory bowel disease. However, it can arise as a paradoxical side effect of anti-TNF treatment.

Methods

The article reports on three patients with Crohn's disease who developed hidradenitis suppurativa during the treatment with adalimumab.

Results

Case 1: A 38-year-old female exhibited an infiltrative lesion in the inguinal region and vulva, consistent with hidradenitis suppurativa, after three months of adalimumab. These lesions were treated with partial vulvectomy. Case 2: After adalimumab treatment, a 27-year-old female, originally diagnosed with ileocolonic Crohn's disease, went into clinical and endoscopic remission. The patient eventually presented two hyperchromic nodules in the inguinal region, which were diagnosed as hidradenitis suppurativa. The patient showed improvement after treatment with oral doxycycline and local therapy. Case 3: A 34-year-old female with fistulizing and stenosing ileocolonic Crohn's disease, started adalimumab in 2010, with optimization in 2015. One year after, the patient developed bilateral, erythematous, hardened, inguinal nodulations with purulent drainage, consistent with hidradenitis suppurativa. Treatment with oral doxycycline, fusidic acid, and infiltration with triamcinolone resulted in partial improvement of the lesions. In 2018, the lesions deteriorate. The patient underwent surgical treatment.

Conclusion

Patients with inflammatory bowel disease are more likely to the development of other mediated inflammatory diseases, such as hidradenitis suppurativa. Hidradenitis suppurativa may appear as a paradoxical reaction to anti-TNF therapy. Clinical teams must be aware of this type of complication. Early diagnosis and treatment are essential for controlling the disease and preventing the onset of complications.

Immunomodulatory drugs alone and adjuvant to surgery for hidradenitis suppurativa/acne inversa-A narrative review

Hidradenitis suppurativa/acne inversa (HS/AI) is one of the most debilitating dermatoses with a strong negative impact on every dimension of quality of life. Treatment is dependent on the severity of clinical manifestations and comorbidities. While anti-inflammatory and antimicrobial approaches are recommended for mild and moderate stages, immunomodulatory drugs have gained increasing interest in all stages of HS/AI. We reviewed the available data on this subject in a narrative review and included not only substances with published final outcome but those where either the ongoing trials or experience from case report. Furthermore, we investigated combined surgical therapy and immunomodulatory drugs and raised specific questions to be answered in controlled settings. This aspect seems to be underrepresented. The first approved medical treatment for HS/AI is adalimumab. Other cytokine, interleukin, Janus kinase and C5a inhibitors and antagonists are under investigation. IL-1 inhibitors and antagonists may become an option for mild to moderate HS/AI, while most of the other medical compounds target moderate to severe HS/AI. Despite medical efforts with immunomodulatory agents, surgery remains a cornerstone of efficient HS/AI therapy. Better outcome in advanced disease might be achieved by combining drug therapy and surgery, but more systematic clinical trials are necessary for the optimal combination.

Identification of Hidradenitis Suppurativa-Related mRNA Expression Patterns Through Analysis of Gene Expression Omnibus

Background:

Hidradenitis suppurativa (HS) is a chronic, follicular, and inflammatory skin disease with multifactorial pathogenesis, and its definite molecule mechanism is still not fully elucidated.

Objective:

The purpose of this research was to identify crucial differentially expressed genes (DEGs) and biological processes and pathways involved in HS through bioinformatics analysis.

Methods:

A total of 30 tissues from patients with HS, 17 lesional and 13 healthy, were obtained from the GSE72702 data set of the Gene Expression Omnibus database. The DEGs were sorted by GEO2R and analyzed by Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis. MCODE analysis was visualized using Cytoscape.

Results:

Of the 723 identified DEGs, 364 were upregulated and 359 were downregulated. Upregulated DEGs were significantly enriched in immune response, inflammatory response, tumor necrosis factor signaling pathway, and so on and downregulated DEGs were enriched in the positive regulation of the peroxisome proliferators-activated receptor pathways, the regulation of lipolysis in adipocytes, and so on. The most significant DEGs group of 35 genes were screened.

Conclusion:

The internal biological information in HS can be revealed by bioinformatic methods, providing direction for further research and potential therapeutic targets.

Comparative Overall Comorbidity Burden Among Patients With Hidradenitis Suppurativa

Importance

The overall comorbidity burden among patients with hidradenitis suppurativa (HS) has not been systematically evaluated.

Objectives

To investigate the standardized overall comorbidity burden among patients with HS and to compare it with the comorbidity burden in patients with psoriasis and a control group.

Design, Setting, and Participants

A cross-sectional analysis was conducted of 5306 patients with HS, 14 037 patients with psoriasis, and 1 733 810 controls identified using electronic health records data from October 1, 2013, through October 1, 2018.

Main Outcome and Measure

The primary outcome was the mean Charlson Comorbidity Index (CCI) score.

Results

Each matched cohort had 3818 patients (2789 women and 1029 men; mean [SD] age, 45.7 [15.0]). Before matching, the overall mean (SD) CCI score was highest among the psoriasis cohort (2.33 [3.13]), followed by the HS cohort (1.80 [2.79]) and control cohort (1.26 [2.35]). In matched analyses, the overall mean (SD) CCI score was highest among the HS cohort (1.95 [2.96]), followed by the psoriasis cohort (1.47 [2.43]; P < .001) and control cohort (0.95 [1.99]; P < .001) patients. A total of 516 patients with HS (13.5%) had an overall mean CCI score of 5 or greater. Mean CCI score was highest for patients with HS across all sex, race, and age groups. The most common comorbidities among patients with HS were chronic pulmonary disease (1540 [40.3%]), diabetes with chronic complications (365 [9.6%]), diabetes without chronic complications (927 [24.3%]), and mild liver disease (455 [11.9%]). Patients with HS with a CCI score of 5 or greater had 4.97 (95% CI, 1.49-16.63) times the adjusted risk of 5-year mortality compared with patients with HS with a CCI score of zero.

Conclusions and Relevance

Patients with HS have a higher overall comorbidity burden compared with patients with psoriasis and a control group. A significant proportion of patients with HS have CCI scores of 5 or greater, which are associated with increased mortality. This degree of comorbidity burden may warrant multidisciplinary implementation of routine screening measures.

Evidence for a 'window of opportunity' in hidradenitis suppurativa treated with adalimumab: a retrospective, real-life multicentre cohort study

BACKGROUND

The anti-tumour necrosis factor (TNF)-α adalimumab is the only licenced biologic for moderate-to-severe hidradenitis suppurativa (HS). No predictors of response have been identified so far.

OBJECTIVES

To identify clinical parameters predicting response to adalimumab and confirm its efficacy/safety.

METHODS

The data of 389 patients with HS treated with adalimumab in 21 Italian centres were reviewed. Sex, age at onset/diagnosis/baseline, body mass index, smoking, phenotype, previous treatments, concomitant antibiotics and 'therapeutic delay', defined as the time from HS onset to adalimumab initiation, were assessed. Response to adalimumab and its impact on quality of life (QoL) were evaluated using the Hidradenitis Suppurativa Clinical Response (HiSCR) and the Dermatology Life Quality Index (DLQI) or the Visual Analogue Scale for pain (VAS pain), respectively. Logistic regression analysis was performed.

RESULTS

The therapeutic delay correlated to lack of response to adalimumab at week 16 [odds ratio (OR) 1·92 for therapeutic delay > 10 years; 95% confidence interval (CI) 1·28-2·89; P = 0·0016). HiSCR was achieved in 43·7% and 53·9% patients at week 16 and 52, respectively. Significant reductions in both DLQI and VAS pain were found between week 16 vs. baseline (P < 0·0001 for both) and week 52 vs. baseline (P < 0·0001 for both). Previous immunosuppressants inversely correlated to HiSCR at week 52 (OR = 1·74, 95% CI 1·04-2·91, P = 0·0342).

CONCLUSIONS

Inverse correlation between therapeutic delay and clinical response was found, supporting early adalimumab use and providing evidence for a 'window of opportunity' in HS treatment. Adalimumab efficacy and safety were confirmed, along with patients' QoL improvement. Immunosuppressants could negatively influence the response to adalimumab inducing a switch to non-TNF-α-driven pathways.

Hidradenitis suppurativa

Hidradenitis suppurativa (HS; also designated as acne inversa) is a chronic inflammatory disorder, which affects the intertriginous skin and is associated with numerous systemic comorbidities. The estimated prevalence of HS is ~1% in most studied countries. Typically starting in early adulthood, cutaneous inflamed nodules, abscesses and pus-discharging tunnels develop in axillary, inguinal, gluteal and perianal body sites. The comorbidities of HS include metabolic and cardiovascular disorders, which contribute to reduced life expectancy. A genetic predisposition, smoking, obesity and hormonal factors are established aetiological factors for HS. Cutaneous changes seem to start around hair follicles and involve activation of cells of the innate and adaptive immune systems, with pivotal roles for pro-inflammatory cytokines such as tumour necrosis factor, IL-1β and IL-17. The unrestricted and chronic immune response eventually leads to severe pain, pus discharge, irreversible tissue destruction and scar development. HS has profound negative effects on patients' quality of life, which often culminate in social withdrawal, unemployment, depression and suicidal thoughts. The therapeutic options for HS comprise antibiotic treatment, neutralization of tumour necrosis factor and surgical intervention together with lifestyle modification. Nevertheless, there is an enormous need for awareness of HS, understanding of its pathogenesis and novel treatments.

Paradoxical Hidradenitis Suppurativa in Patients Receiving TNF-α Inhibitors: Case Series, Systematic Review, and Case Meta-Analysis

BACKGROUND/AIMS

TNF-α inhibitors represent the most advanced approved therapeutic option for moderate and severe forms of hidradenitis suppurativa (HS). However, in recent years, cases of paradoxical HS secondary to the use of these biological drugs have been described, with very few cases reported in the literature. The aims of this study are (1) to present 2 new cases of paradoxical HS and (2) to perform a systematic review of scientific evidence regarding paradoxical HS with TNF-α inhibitors.

MATERIAL AND METHODS

This is a retrospective study in which we searched all the cases of paradoxical HS secondary to the use of TNF-α inhibitors published in the literature and included two additional cases observed in our clinical practice.

RESULTS

A total of 34 patients under TNF-α inhibitor treatment were included (adalimumab = 21; infliximab = 9; etanercept = 4). The median delay from exposure to TNF-α inhibitor and the development of paradoxical HS was 12 months (range 1-72). The majority of patients were Hurley stage II (58.8%). Clinical improvement and complete remission were more frequent when the TNF-α inhibitor was stopped or switched to another biological agent with a different therapeutic target rather than maintenance or change to another TNF-α inhibitor.

CONCLUSIONS

Paradoxical HS is an unusual adverse effect of TNF-α inhibitors. When this adverse effect appears, interruption or substitution of treatment is associated with a better clinical outcome.

Long-term safety of adalimumab for patients with moderate-to-severe hidradenitis suppurativa

Introduction: Hidradenitis suppurativa (HS) is a chronic debilitating inflammatory skin disorder that affects regions rich in apocrine glands. Although the etiology of HS is not clear, inflammatory cytokines, like tumor necrosis factor (TNF)-α, participate in pathogenesis. Adalimumab (ADA), a human IgG1 monoclonal antibody that selectively targets TNFα, is the only EMA/FDA-approved biologic agent available for the therapy of moderate-to-severe HS.Areas covered: A comprehensive literature search was conducted to present existing studies with an emphasis on the safety profile of ADA for the treatment of moderate-to-severe HS. ADA is prescribed for more than 15 years for varied indications and has improved the therapeutic outcomes of many diseases. Clinical trials and real-life safety data from ADA administration in HS were presented, with particular attention to special populations, such as children, elderly, and pregnant women.Expert opinion: Existing data advise for limited safety concerns with long-term ADA treatment provided that patients are thoroughly screened for infections, latent tuberculosis, and history of malignancy before the start of treatment.