TNF-α inhibitors in the treatment of hidradenitis suppurativa

Effect of adalimumab treatment on inflammatory and hematological parameters in patients with Hidradenitis suppurativa

OBJECTIVE

Hidradenitis suppurativa (HS), a chronic inflammatory disease that typically manifests after puberty, is characterised by painful nodules, abscesses, draining sinus tracts, and scars in areas rich in apocrine glands such as the axillary and inguinal regions. In recent years, blood-based biomarkers such as the Neutrophil/Lymphocyte Ratio (NLR), Platelet/Lymphocyte Ratio (PLR), Monocyte/Lymphocyte Ratio (MLR), Mean Platelet Volume (MPV), Systemic Immune-Inflammation Index (SII) and Pan-Immune-Inflammation Value (PIV) have been used as significant indicators of systemic inflammation. While there are few studies evaluating these biomarkers in HS, the response of these markers to treatment has only been assessed in one study to date. Our study aims to investigate the effect of adalimumab treatment on blood-based systemic inflammation biomarkers in HS, where inflammation plays a significant role.

METHODS

The study included 42 adult patients who received adalimumab treatment at our dermatology and venereology clinic between January 2020 and January 2023. Medical records for complete blood count results of the patients were retrospectively reviewed. All systemic inflammation-based biomarkers were calculated from the absolute values of the complete blood count. The SII was calculated with the following formula: (neutrophil count × platelet count/lymphocyte count). The PIV was calculated as follows: (neutrophil count × platelet count × monocyte count/lymphocyte count). Values before the treatment and at the 12th week of treatment were compared.

RESULTS

When the changes in the inflammatory parameters of the patients were examined, it was found that NLR (2.13 ± 0.87 vs 2.26 ± 1.12), PLR (111.01 ± 39.89 vs 99.43 ± 35.34), MLR (0.27 ± 0.11 vs 0.28 ± 0.12), MPV (9.59 ± 0.71 vs 9.70 ± 0.79), SII (680.79 ± 330.18 vs 687.89 ± 442.66), and PIV (552.02 ± 330.71 vs 605.05 ± 415.96) values did not change statistically significantly after treatment (p > 0.05). While there was a significant decrease in platelet count compared to before treatment, no statistically significant difference was found in the other evaluated blood cells.

CONCLUSION

Adalimumab treatment has not had a significant effect on systemic inflammation markers in HS, an inflammatory disease. More studies are needed to evaluate the effect of adalimumab on these markers in HS.

Conventional and Novel Treatment Strategies for Porokeratoses: A Narrative Review

Porokeratoses are a heterogenous group of autoinflammatory keratinization disorders all characterized by the presence of a cornoid lamella. In addition to gene mutations affecting the mevalonate pathway, environmental factors such as UV radiation, immunosuppression, trauma, and infection are also thought to contribute to porokeratoses. To date, there are no management guidelines or levels of evidence for commonly used pharmacologic and non-pharmacologic treatment options for porokeratoses. Conventional treatment strategies encompass topical and systemic drugs (e.g., salicylic acid, topical glucocorticoids, and retinoids), phototherapy, laser, and surgical interventions. Better insights into the pathogenesis of porokeratoses have paved the way for the development of novel therapeutic approaches, such as topical statins or the use of monoclonal antibodies. This narrative review aims to summarize both conventional and novel treatment options, including their level of evidence, advantages, and disadvantages.

Konventionelle und neue Behandlungsstrategien bei Porokeratosen: Eine narrative Übersicht

Porokeratosen sind eine heterogene Gruppe autoinflammatorischer Keratinisierungsstörungen, die durch kornoide Lamellen gekennzeichnet sind. Neben Genmutationen, die sich auf den Mevalonat‐Stoffwechselweg auswirken, werden auch Umweltfaktoren wie UV‐Strahlung, Immunsuppression, Traumata und Infektionen für die Entstehung von Porokeratosen verantwortlich gemacht. Bislang gibt es keine Behandlungsrichtlinien oder Evidenzgrade für die gängigen pharmakologischen und nicht‐pharmakologischen Behandlungsoptionen bei Porokeratosen. Zu den konventionellen Behandlungen zählen topische und systemische Medikamente wie Salicylsäure, topische Glucocorticoide und Retinoide, Phototherapie, Laser und chirurgische Verfahren. Bessere Erkenntnisse über die Pathogenese von Porokeratosen haben die Entwicklung neuartiger therapeutischer Ansätze ermöglicht, etwa topische Statine oder monoklonale Antikörper. In dieser narrativen Übersichtsarbeit werden sowohl die herkömmlichen als auch neuen Behandlungsmöglichkeiten einschließlich ihres Evidenzgrads sowie ihrer Vor‐ und Nachteile zusammengefasst.

Single-cell mass cytometry in immunological skin diseases

Immune-related skin diseases represent a collective of dermatological disorders intricately linked to dysfunctional immune system processes. These conditions are primarily characterized by an immoderate activation of the immune system or deviant immune responses, involving diverse immune components including immune cells, antibodies, and inflammatory mediators. However, the precise molecular dysregulation underlying numerous individual cases of these diseases and unique subsets respond under disease conditions remains elusive. Comprehending the mechanisms and determinants governing the homeostasis and functionality of diseases could offer potential therapeutic opportunities for intervention. Mass cytometry enables precise and high-throughput quantitative measurement of proteins within individual cells by utilizing antibodies labeled with rare heavy metal isotopes. Imaging mass cytometry employs mass spectrometry to obtain spatial information on cell-to-cell interactions within tissue sections, simultaneously utilizing more than 40 markers. The application of single-cell mass cytometry presents a unique opportunity to conduct highly multiplexed analysis at the single-cell level, thereby revolutionizing our understanding of cell population heterogeneity and hierarchy, cellular states, multiplexed signaling pathways, proteolysis products, and mRNA transcripts specifically in the context of many autoimmune diseases. This information holds the potential to offer novel approaches for the diagnosis, prognostic assessment, and monitoring responses to treatment, thereby enriching our strategies in managing the respective conditions. This review summarizes the present-day utilization of single-cell mass cytometry in studying immune-related skin diseases, highlighting its advantages and limitations. This technique will become increasingly prevalent in conducting extensive investigations into these disorders, ultimately yielding significant contributions to their accurate diagnosis and efficacious therapeutic interventions.

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.

Golimumab and certolizumab pegol for the treatment of hidradenitis suppurativa: a literature review and future perspective

Hidradenitis suppurativa (HS) is an inflammatory skin condition with an underlying inflammatory process. Due to the limited efficacy of available treatments, HS remains a therapeutic challenge. The safety and efficacy of tumor necrosis factor-α (TNF-α) inhibitors, adalimumab, infliximab, and etanercept, are well studied in this patient population, and in some cases, HS was unresponsive to them. In recent years, evidence has been growing regarding the application of other anti-TNFs, including certolizumab pegol (CPZ) and golimumab. We sought to evaluate the overall safety and efficacy of golimumab and CPZ in the management of HS. A comprehensive search was performed on the PubMed, Scopus, Web of Science, and Ovid Embase databases, as well as the Google Scholar search engine from initiation to 31 August 2023. A total of nine and four studies used CPZ and golimumab to treat HS, respectively. Individuals with concomitant inflammatory immune-mediated diseases, pregnant females, and patients who were refractory to previous treatments achieved a Hidradenitis Suppurativa Clinical Response following CPZ administration. Also, golimumab showed promise in treating recalcitrant HS after the failure of other treatments, such as adalimumab and anti-interleukin-1. CPZ and golimumab can be efficacious treatment options for moderate-to-severe HS, especially in patients who are unresponsive to other TNF inhibitors, such as adalimumab.

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.

The totality of evidence approach in the development of AVT02 (adalimumab), a biosimilar to Humira

The development of a biosimilar is based on comparative structural, physicochemical, functional and clinical assessments. The sum of these analyses encompasses the 'totality of evidence', which demonstrates no clinically meaningful differences between the biosimilar and the reference product (RP). Once biosimilarity has been established, provided there is suitable scientific justification, clinical data may be extrapolated to other indications of the RP. AVT02 has been developed as a biosimilar to high-concentration, low-volume Humira (adalimumab), an anti-tumour necrosis factor-alpha monoclonal antibody approved for various chronic inflammatory indications. The totality of evidence for AVT02 is described, supporting its approval as an adalimumab biosimilar for all approved indications globally. Analytical similarity assessments using mass spectrometry methods demonstrated identical amino acid sequences for AVT02 and the RP, with high similarity in terms of primary structure, post-translational modifications and higher-order structural attributes. The mechanism of action was assessed by various cell-based potency assays and binding assays, and the results demonstrated that AVT02 is highly similar to the RP. No clinically meaningful differences in terms of purity, potency and safety were observed, and minor differences in a few physiochemical attributes did not impact the in vitro biologic activity and were not considered clinically relevant. Clinical similarity was demonstrated by comparing the pharmacokinetic, efficacy, safety and immunogenicity profiles of AVT02 with those of the RP. Clinical studies supported similar pharmacokinetic and comparable immunogenicity profiles between AVT02 and the RP in healthy participants and participants with moderate-to-severe chronic plaque psoriasis, with no new safety signals detected. The totality of evidence described demonstrates the biosimilarity of AVT02 to the RP, thereby fulfilling the scientific and regulatory requirements for AVT02 as a high-concentration biosimilar for the treatment of chronic plaque psoriasis and all approved indications of the RP.

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

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

Narrative Review and Update on Biologic and Small Molecule Drugs for Hidradenitis Suppurativa: An Entity With a Promising Future

Hidradenitis suppurativa (HS) is a chronic inflammatory entity characterized by the appearance of multiple nodules, abscesses, and fistulas, predominantly in apocrine regions. In addition to its dermatological involvement, it is associated with multiple systemic comorbidities. Its treatment is combined: topical pharmacological, systemic pharmacological and surgical. Regarding biologic or small molecule drugs, currently only adalimumab is approved. A narrative review of the literature on biological or small molecule drugs used in the treatment of hidradenitis suppurativa is presented. The arsenal we found is large, with multiple targets: inhibitors of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-17, IL-23, IL-1, inhibitors of the janus kinase (JAK) pathway, and multiple other drugs in study. New prospective studies and comparative trials are needed to analyze the effectiveness and safety of these treatments, in an entity with a promising future.

Narrative Review and Update on Biologic and Small Molecule Drugs for Hidradenitis Suppurativa: An Entity With a Promising Future

Hidradenitis suppurativa (HS) is a chronic inflammatory entity characterized by the appearance of multiple nodules, abscesses, and fistulas, predominantly in apocrine regions. In addition to its dermatological involvement, it is associated with multiple systemic comorbidities. Its treatment is combined: topical pharmacological, systemic pharmacological and surgical. Regarding biologic or small molecule drugs, currently only adalimumab is approved. A narrative review of the literature on biological or small molecule drugs used in the treatment of hidradenitis suppurativa is presented. The arsenal we found is large, with multiple targets: inhibitors of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-17, IL-23, IL-1, inhibitors of the janus kinase (JAK) pathway, and multiple other drugs in study. New prospective studies and comparative trials are needed to analyze the effectiveness and safety of these treatments, in an entity with a promising future.

Hidradenitis suppurativa and follicular occlusion syndrome: Where is the pathogenetic link?

The follicular occlusion tetrad complex encompasses several entities (hidradenitis suppurativa, acne conglobata, dissecting cellulitis of the scalp, and pilonidal cyst) that share common clinical features, risk factors, and pathophysiology. Follicular occlusion is a crucial triggering mechanism in the etiology in each of these disorders, leading to development of distinctive skin lesions such as deep-seated nodules, abscesses, comedones, and draining sinuses, often with accompanying scarring. Despite the fact that the follicular occlusion tetrad components manifest multiple similarities, they also exhibit many differences among themselves and require individual approaches and treatment.

Disease Association of Anti‒Carboxyethyl Lysine Autoantibodies in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurring suppurating lesions of the intertriginous areas, resulting in a substantial impact on patients' QOL. HS pathogenesis remains poorly understood. An autoimmune component has been proposed, but disease-specific autoantibodies, autoantigens, or autoreactive T cells have yet to be described. In this study, we identify a high prevalence of IgM, IgG, and IgA antibodies directed against Nε-carboxyethyl lysine (CEL), a methylglyoxal-induced advanced glycation end-product, in the sera of patients with HS. Titers of anti-CEL IgG and IgA antibodies were highly elevated in HS compared with those in healthy controls and individuals with other inflammatory skin diseases. Strikingly, the majority of anti-CEL IgG was of the IgG2 subclass and correlated independently with both disease severity and duration. Both CEL and anti-CEL‒producing plasmablasts could be isolated directly from HS skin lesions, further confirming the disease relevance of this autoimmune response. Our data point to an aberration of the methylglyoxal pathway in HS and support an autoimmune axis in the pathogenesis of this debilitating disease.

Biologics and Small Molecule Inhibitors for Treating Hidradenitis Suppurativa: A Systematic Review and Meta-Analysis

BACKGROUND

The treatment guidelines for hidradenitis suppurativa (HS) vary among different countries, and several biologics and small molecule inhibitors have been tested for treating moderate-to-severe HS over the past few years. However, treatment guidelines for HS vary among different countries.

METHODS

A systematic review and meta-analysis was performed to exam the efficacy and serious adverse events (SAEs) of biologics and small-molecule inhibitors in treating moderate-to-severe HS. Binary outcomes were presented as risk ratio (RR) with 95% confidence interval (CI).

RESULTS

We included 16 RCTs with a total of 2076 participants on nine biologics and three small-molecule inhibitors for treating moderate-to-severe HS, including adalimumab, anakinra, apremilast, avacopan, bimekizumab, CJM112, etanercept, guselkumab, IFX-1, INCB054707, infliximab, and MABp1. The meta-analysis revealed only adalimumab (RR 1.77, 95% CI, 1.44-2.17) and bimekizumab (RR 2.25, 95% CI, 1.03-4.92) achieved significant improvement on hidradenitis suppurativa clinical response (HiSCR), and adalimumab was superior to placebo in achieving dermatology life quality index (DLQI) 0/1 (RR 3.97; 95% CI, 1.70-9.28). No increase in SAEs was found for all included active treatments when compared with placebo.

CONCLUSIONS

Adalimumab and bimekizumab are the only two biologics effective in achieving HiSCR with acceptable safety profile, whereas adalimumab is the only biologic effective in achieving DLQI 0/1.

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).

Development of a specialty medication clinical dashboard to improve tumor necrosis factor-α inhibitor safety and adherence monitoring

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

To describe the development of a pilot specialty medication clinical dashboard targeting tumor necrosis factor (TNF)-α inhibitor therapy.

SUMMARY

This was a quality improvement project conducted between August 2019 and April 2020. The dashboard was designed with collaboration between clinical pharmacists and specialty providers in rheumatology, gastroenterology, and dermatology. Data was queried from the Veterans Affairs Corporate Data Warehouse. Patients with an active prescription or intravenous order for a TNF-α inhibitor were included. Dashboard flag criteria focused on TNF-α inhibitor safety and adherence monitoring. Flag results from the dashboard were characterized from data captured at a single time point. For 431 patients on TNF-α inhibitor treatment at the institution, 304 flags corresponding to 223 unique patients (51.7%) were identified on the dashboard: 3% of patients had a new infection, 9% had overdue monitoring laboratory tests, 5% had a critical laboratory result, 2% were on 2 biologic agents, 27% were overdue for a refill, 6% had an emergency department visit, and 2% had an inpatient admission. No patients were flagged for heart failure exacerbation or new malignancy. Seventeen percent of patients were prescribed high-dose etanercept or adalimumab, representing a potential annual cost savings of $302,497 if 50% of these patients had their dose successfully reduced to labeled dosing. Opportunities for pharmacist intervention utilizing the dashboard were identified and characterized through chart review of flagged patients.

CONCLUSION

Pharmacists have the opportunity to improve safety and adherence for TNF-α inhibitor therapy through use of a specialty medication clinical dashboard. The dashboard should be used in conjunction with collaborative practice protocols.

Insights into the Pathogenesis of HS and Therapeutical Approaches

Hidradenitis suppurativa (HS) is a debilitating, chronic, (auto)inflammatory disease primarily affecting apocrine gland-rich areas of the body. Although pathogenic mechanisms responsible for HS have not yet been fully elucidated, it is a multifactorial process whose main target is the terminal follicle. The role of the inflammatory process (and consequently of cytokine milieu) and of several other factors (genetics, lifestyle, hormonal status, microbiome, innate and adaptive immune systems) involved in HS pathogenesis has been investigated (and often defined) over the years with a view to transferring research results from bench to bedside and describing a unique and universally accepted pathogenetic model. This review will update readers on recent advances in our understanding of HS pathogenesis and novel (potential) medical therapies for patients with moderate-to-severe HS.

Clinical Epidemiology and Management of Hidradenitis Suppurativa

Hidradenitis suppurativa is a chronic immune-mediated inflammatory skin disease with a prevalence of 0.1-1%, characterized by nodules and abscesses in the axillae, groin, and inframammary areas, sometimes developing into tunnels (or fistulas) and scars. Because hidradenitis suppurativa is more common in women and in those aged 18-40 years, obstetrician-gynecologists (ob-gyns) have the opportunity to diagnose, educate, initiate treatment, and coordinate care with ancillary health care professionals. The recently published North American treatment guidelines, along with management information for patients with hidradenitis suppurativa who are pregnant or breastfeeding, are summarized. By diagnosing and optimizing hidradenitis suppurativa treatment early in the disease course, ob-gyns can reduce morbidity, with the potential to favorably alter disease trajectory.

Adalimumab Induces a Wound Healing Profile in Patients with Hidradenitis Suppurativa by Regulating Macrophage Differentiation and Matrix Metalloproteinase Expression

Adalimumab (ADA) is the only Food and Drug Administration‒approved treatment for moderate-to-severe hidradenitis suppurativa, whereas etanercept and certolizumab-pegol have been shown to be ineffective, suggesting that the mechanism of action of ADA is distinct in hidradenitis suppurativa and may contribute to improved wound healing. Given that macrophages (Mϕs) play pivotal roles throughout the wound healing process, an in vitro Mϕ differentiation assay was carried out to assess the impact of TNF‒anti-TNF complexes on these cells. TNF‒ADA complexes exhibited stronger inhibitory effects on inflammatory Mϕ differentiation. Moreover, RNA sequencing revealed several unique wound healing profiles for TNF‒ADA‒treated inflammatory Mϕs, which were not observed for those treated with either TNF‒etanercept or TNF‒certolizumab-pegol complexes, including the inhibition of the matrix metalloproteinase (MMP) pathway. In addition, ADA administration was found to significantly reduce the levels of inflammatory MMP-1 and MMP-9 while promoting wound-healing MMP-13 and tissue inhibitor of metalloproteinases 2 levels in the circulation of the patients with hidradenitis suppurativa who responded to treatment. Our in vitro findings show that TNF‒ADA‒treated inflammatory Mϕs exhibit a distinct profile resembling wound healing. Moreover, ADA not only differentially regulates MMP expression in patients with hidradenitis suppurativa responding to the therapy but also potentially induces a transition to a profile suggestive of wound healing.

Association of hidradenitis suppurativa with Crohn’s disease

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder characterized by recurrent nodules, abscesses, and sinus tracts. Crohn’s disease (CD) is characterized by inflammation of the entire digestive tract and belongs to the group of inflammatory bowel diseases, and there are many extraintestinal manifestations, among which hidradenitis suppurativa is one of the rare extraintestinal manifestations. There appears to be a strong association between CD and HS based on clinical and histological similarities (sinus tract development, granulomatous inflammation, and scarring), intersections in pathogenesis (genetic loci, immune dysregulation mechanisms, and microbiome changes), and commonality in treatment. In this review, we summarize recent studies on the association between HS and CD.

Is There a Role for Therapeutic Drug Monitoring in Patients with Hidradenitis Suppurativa on Tumor Necrosis Factor-α Inhibitors?

Tumor necrosis factor-α inhibitors, adalimumab and infliximab, are at the forefront of biologic therapy for the management of moderate-to-severe hidradenitis suppurativa, with adalimumab as currently the only approved medication for this condition. In treating patients, primary or secondary lack of response (also termed suboptimal response) is a major burden for both patients and healthcare systems and is a challenge with biologics in part owing to the development of anti-drug antibodies following treatment. To overcome this, therapeutic drug monitoring may be conducted proactively or reactively to a patient's suboptimal response guided by measurements of trough serum drug concentrations and levels of anti-drug antibodies. While strong evidence to support the utility of therapeutic drug monitoring exists in patients with inflammatory bowel disease, current information is limited in the context of hidradenitis suppurativa. We sought to summarize the available evidence and to present the role of therapeutic drug monitoring and other dose optimization strategies in improving clinical response in patients with hidradenitis suppurativa treated with tumor necrosis factor-α inhibitors.

Various skin manifestations related to inflammatory bowel disease: A nationwide cross-sectional study on the Korean population

Inflammatory bowel disease (IBD) presents with various extraintestinal manifestations. As part of them, various skin diseases are suggested to be related to IBD. We aimed to identify the epidemiology and risk of developing skin manifestations in patients with IBD. We used Korean insurance claims data and selected patients with IBD and age/sex-matched non-IBD subjects between 2013 and 2017 using the diagnosis code and prescription records of IBD-specific medications. The prevalence and risk of concurrent skin diseases were estimated. We identified 64 837 patients with IBD. Reactive skin eruptions including pyoderma gangrenosum and erythema nodosum were associated with IBD with highest odds ratios among three categories of reactive, inflammatory, and autoimmune skin diseases. Inflammatory skin diseases including rosacea, psoriasis, atopic dermatitis, hidradenitis suppurativa, and acne conglobata were significantly associated with IBD, but the association was less marked compared to reactive skin eruptions. The patients with IBD also had a higher risk of autoimmune skin diseases including vitiligo and alopecia areata than non-IBD subjects. We determined that IBD was related to various skin diseases including reactive, inflammatory, and autoimmune skin diseases. Considering these relationships can allow better management of patients with IBD and comorbid skin diseases.

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.

Molecular skin changes in Cushing syndrome and the effects of treatment

OBJECTIVE

We investigated newly diagnosed patients with endogenous CS for molecular changes in skin by biopsy before and a year after treatment of CS.

PATIENTS AND METHODS

26 Patients with CS and 23 healthy controls were included. All the patients were evaluated before and a year after treatment. Skin biopsies were obtained from abdominal region before and a year after treatment in patients with CS and once from healthy volunteers. Total RNA was isolated from the skin biopsy samples and the real-time PCR system was used to determine the expression levels of 23 genes in the skin biopsy.

RESULTS

Skin expression levels of HAS 1, 2 and 3 mRNAs were lower and COL1A2, COL2A1, COL3A1 mRNAs were higher in patients with CS than in normal controls. MMP-9, TIMP-1 and elastin mRNA expression levels were similar in two groups. Skin IL-1β mRNA expression level was significantly higher in patients with CS. None of these parameters changed significantly 12 months after treatment. Patients with CS showed higher skin GH and HSD11B1 mRNA expressions and lower GHR and IGF-1R mRNA expression compared to control. Expression levels of IGF-1, GR and HSD11B2 mRNA were similar in two groups. None of these parameters changed significantly 12 months after treatment.

CONCLUSION

CS is associated with increased expression levels of skin COL1A2, COL2A1, COL3A1 mRNAs (which are correlated with increased expression level of skin GH mRNA). Decreased skin HAS may cause decreased synthesis of HA that contributes to thinning of skin in CS. Increased local inflammatory cytokine and HSD11B1 mRNAs may be related to the acne formation in CS. Treatment of CS was not able to reverse these changes and ongoing changes were detected after treatment.

Cytokine Pathways and Investigational Target Therapies in Hidradenitis Suppurativa

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting areas with a high density of apocrine glands and characterized by subcutaneous nodules that may evolve into fistulas with pus secretion. Methods: The aim of this review is to investigate all current knowledge on cytokine regulation in the pathogenesis of HS. A systematic literature research using the words “cytokine”, “interleukin”, “pathway”, and “hidradenitis suppurativa” was performed in PubMed/Medline and Scopus/Embase databases. A search of the clinicaltrials.gov website for interventional recruiting and completed trials including the term “hidradenitis suppurativa” was also performed up to August 2020. We will discuss the pathogenetic role of various cytokines in HS and potential therapeutic targets for this debilitating disease. Results: The pathophysiology underlying this complex condition has not been clearly defined. An upregulation of various cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, IL-17, IL-23, and other molecules seems to be related to this inflammatory condition. Various cells, such as lymphocytes T Helper 1 and 17 and keratinocytes seem to be involved in the genesis of this condition. Conclusions: Several future studies and clinical trials are necessary in order to have new knowledge about HS and to properly treat this complex condition.

Hidradenitis suppurativa: infection, autoimmunity, or both?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease mainly affecting areas rich in apocrine glands. Clinically, is characterized by painful subcutaneous nodules and if left untreated to pus secretion, abscess and fistula formation. Its frequency is estimated to be 0.5-4% of the general population, affecting women more often. Pathogenesis of HS is still not clearly defined. It seems to be a combination of genetic factors with alterations in the skin microbiome. Furthermore, at tissue (i.e. skin) as well as at serum level, several inflammatory cytokines are upregulated. The most important of the latter are tumor necrosis factor (TNF), interleukin (IL)-1, IL-17, and IL-23. Adding another level of complexity, it has been suggested that keratinocytes might be intrinsically activated, contributing also to the observed inflammation. Interestingly, it has been noted that frequency of HS is increased in some autoimmune rheumatic diseases, such as spondyloarthropathies (SpA). Of note, both HS and SpA have relatively strong association with metabolic diseases and obesity implying that there are indeed some common underlying pathophysiological pathways. Although no specific microbe has been identified, alterations in the microbiome of the skin of these patients have been reported. Of note, microbes with a capability for biofilm formation are abundant. Treatment of HS among others, include antibiotics as well as biologic drugs targeting TNF and other cytokines and used for autoimmune rheumatic diseases. Herein, we review the current evidence on links between HS and autoimmune diseases and infectious diseases with a focus on epidemiology and pathophysiology.