Targeted treatments for hidradenitis suppurativa: a review of the current literature and ongoing clinical trials

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Guselkumab, Risankizumab, and Tildrakizumab in the Management of Hidradenitis Suppurativa: A Review of Existing Trials and Real-Life Data

The treatment of hidradenitis suppurativa (HS) has always been a real challenge for dermatologists; to date, the only biologic drugs approved for HS are adalimumab, an anti-tumor necrosis factor (TNF)-α drug, authorized in 2015, and secukinumab, recently licensed. The management of this condition is challenging as the available treatments show variable results, and the course of the condition is often chronic-recurrent; therefore, it will be necessary for the future to identify new therapeutic targets for HS. In recent years, studies have focused on the development towards new therapeutic targets. The purpose of our review was to perform a comprehensive literature review of real-life data on anti-IL23 (guselkumab, tildrakizumab, and risankizumab) in HS to summarize the existing evidence on the efficacy and safety of these drugs. We selected 64 articles, among which 32 had the characteristics that we were looking for in our review. To date, the positive data expressed in real-life experiences contrast with the three existing Phase 2 studies conducted so far, where it seems that these drugs may be useful only for a subgroup of patients with HS whose features need to be elucidated. Data from Phase 3 studies and other real-life experiences, perhaps more detailed and with higher numbers, will certainly be needed to fully understand the efficacy and safety of this class of drugs.

Risk of Chronic Kidney Disease in Hospitalized Patients with Hidradenitis Suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is associated with several comorbidities such as diabetes mellitus and cardiovascular diseases. These comorbidities are also risk factors for chronic kidney disease (CKD), yet little is known about the risk of CKD in HS patients.

OBJECTIVES

The objective was to study the prevalence of CKD in HS patients.

METHODS

Cross-sectional population-based study using the United States National Inpatient Sample database between January 1, 2002 and December 31, 2012 was performed.

RESULTS

We identified 23,767 hospital admissions for HS patients and 95,068 admissions for age- and gender-matched controls. The prevalence of CKD in HS patients was 6.3% (1,497/23,767) compared to non-HS controls which was 4.3% (4,052/95,068). The association of CKD was strongest in HS patients, who were ≥60 years old, 16.9% (475/2,811), male 7.3% (695/9,556), obese 7.8% (407/5,209), diabetic 12.5% (890/7,105), hyperlipidemic 13.3% (416/3,126), and had cardiovascular diseases 12.5% (631/5,045). The crude odds ratio of CKD in HS patients was 1.5 (95% CI: 1.420-1.605) compared to non-HS patients. The association remained significant after adjusting for important covariates with adjusted odds ratio of CKD in HS patients of 1.1 (95% CI: 1.014-1.176) compared to non-HS patients.

CONCLUSIONS

Our findings show that there is a possible association of HS with CKD. Any signs of CKD should be assessed by a nephrologist as early diagnosis can hopefully prevent further progression.

Efficacy of the continuous use of a lotion with carbon dioxide on male subjects with mild acne

OBJECTIVE

Acne vulgaris is caused by dyslipidemia, dyskeratosis and/or abnormal bacterial growth. The obstruction of skin pores due to hyperkeratosis of the infundibulum contributes to the formation of comedones. Thus, normalizing keratinization of epidermal cells in skin pores might be useful to improve acne. Recently, it has been found that the transcutaneous application of carbon dioxide (CO₂ ) regulates imbalances of the desquamatory process. In this study, we evaluated the efficacy of a skin lotion containing CO₂ on mild acne.

METHODS

Twenty-four healthy Japanese males (20-29 years old) with mild acne attended this evaluation. The subjects were divided into 2 groups, one group used a skin lotion containing CO₂ and the other group used a skin lotion without CO₂ . Following facial washing, each subject topically applied the skin lotion with or without CO₂ twice a day for 4 weeks. Prior to the start of the evaluation (week 0) and following 2 and 4 weeks of treatment, acne symptoms were assessed by a dermatologist and by instrumental measurements.

RESULTS

Topical application of the skin lotion with CO₂ for 4 weeks significantly improved acne symptoms, which was recognized by the subjects. However, treatment with the skin lotion without CO₂ did not improve acne symptoms. This improvement of acne symptoms by CO₂ was not accompanied by changes in sebum levels, skin surface pH, skin capacitance, or porphyrin levels.

CONCLUSION

The transcutaneous application of a lotion with CO₂ improves acne symptoms by normalizing keratinization without affecting skin surface conditions.

Hepatitis B Virus Reactivation and Mycobacterial Infections Associated With Ustekinumab: A Retrospective Study of an International Pharmacovigilance Database

Background: Reports were recently published on hepatitis B virus reactivation (HBVr), tuberculosis (TB), and atypical mycobacterial infection (AMI) in patients with ustekinumab treatment. However, the literature is limited to case reports and series. The study was aimed to investigate their relationships by using an extensive population-based database.

Methods: Using the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database, we collected all cases of HBVr, TB, and AMI between 1 January 2009 and 30 September 2021, for ustekinumab and other drugs. Disproportionality was analyzed using the reporting odds ratio (ROR), which was considered significant when the lower limit of the 95% confidence interval (95% CI) was >1.

Results: Of the 18,760,438 adverse cases reported to FAERS for all drugs, 56,581 cases had been exposed to ustekinumab. Adverse events of HBVr, TB, and AMI were reported in 21, 210, and 20 cases, respectively. The ROR for HBVr with ustekinumab was 2.33 (95% CI, 1.52–3.58), for TB was 5.09 (95% CI, 4.44–5.84), and for AMI was 2.09 (95% CI, 1.35–3.24). In the ustekinumab exposure group, no death occurred in patients with HBVr, but one patient experienced life-threatening liver failure. For those with TB, 24 cases experienced hospitalization and 2 deaths occurred. No death occurred in patients with AMI but eight experienced hospitalization.

Conclusion: We identified positive signals between ustekinumab exposure and HBVr, TB, and AMI in FAERS. Although these complications are rare, clinicians using ustekinumab should be aware of the risks.

Biologic Use in Hidradenitis Suppurativa: Patient Perspectives and Barriers

INTRODUCTION

Hidradenitis suppurativa (HS) is an inflammatory dermatosis for which the treatment paradigm is rapidly expanding. We aimed to identify HS patient perspectives and barriers on biologics.

METHODS

An anonymous survey was distributed between 10/2021 to 1/2022 through HS support groups. Data regarding demographics and perspectives on biologics were collected and analyzed.

RESULTS

Of the 196 respondents, 92% were female (180/196) and 75% were white (147/196). 89.3% had Hurley stage 2/3 HS (102/195). The primary healthcare provider (HCP) for HS in 65% (128/196) of patients was a dermatologist, with 12% (23/196) seen at an HS specialty clinic. Most respondents never tried a biologic medicine (62%, 118/192). The top barriers to biologics were fear of side effects (61%, 109/179), high cost/lack of insurance coverage (46%, 83/179), frequency of weekly injections (32%, 58/179). Respondents reporting their main HCP as a non-dermatologist (4.11 vs 3.0, p < 0.0001) and not seen at a HS specialty clinic (3.5 vs 2.7, 0.039) were significantly more likely to agree "I do not know enough about how biologics work to help my HS".

CONCLUSION

Our results highlight the importance of specialty care in the education and implementation of biologics. Patients may benefit from comprehensive discussion prior to starting biologics.

The dark side of the moon: the immune-mediated adverse events of IL-17A/IL-17R inhibition

As aberrant IL-17 signaling plays a critical role in the pathogenesis of psoriasis, biologic agents targeting this pathway have become an important weapon against this disease. Some biologic agents such as IL-17 inhibitors (secukinumab and ixekizumab) and the IL-17 receptor (IL17R) inhibitor (brodalumab) are relatively safe, tolerable and efficacious drugs. Nevertheless, side effects of IL-17 pathway inhibition occur. This review focuses on the dermatological manifestations linked to these treatments. Paradoxical psoriasis and atopic-like eczema may be the most common cutaneous adverse events, while manifestations such as neutrophilic dermatoses, hypersensitivity reactions, lichenoid eruptions, vasculitides, bullous diseases, lupus-like reactions, pigmentation disorders, adnexal diseases and granulomatous dermatoses have been described less frequently.

New and Emerging Targeted Therapies for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease deriving from the hair follicles. The formation of inflammatory nodules, abscesses, fistulas, and sinus tracts is characterized by a large inflow of key pro-inflammatory mediators, such as IFN-γ, TNF-α, IL-1, IL-17, and IL-12/23. Adalimumab is currently the only Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved biologic therapy for moderate to severe HS in adults and adolescents. However, the long-term effectiveness of this TNF-α inhibitor in HS patients has shown to be highly variable. This review aims to review the evidence for emerging therapies that target the main pro-inflammatory cytokines in HS pathogenesis. A review of the literature was conducted, using the PubMed and Google Scholar repositories, as well as Clinicaltrials.gov. Presently, the most promising biologics in phase III trials are anti-IL-17 antibodies, secukinumab, and bimekizumab. Furthermore, an anti-IL-1 biologic, bermekimab, is currently in phase II trials, and shows encouraging results. Overall, the clinical efficacies of all new targeted therapies published up to this point are limited. More studies need to be performed to clarify the precise molecular pathology, and assess the efficacy of biological therapies for HS.

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.

Quantifying the natural variation in lesion counts over time in untreated hidradenitis suppurativa: Implications for outcome measures and trial design

Background

Hidradenitis suppurativa (HS) demonstrates high placebo response rates in clinical trials, possibly due to the natural variability of the disease. No quantification of variability in lesion counts of untreated disease has been undertaken.

Objective

To quantify the variability of untreated HS.

Methods

Deidentified individual patient data from the placebo arms of PIONEER studies were analyzed, and measurements of within-subject coefficients of variation were examined. Variability was stratified by disease-associated variables (Hurley stage, BMI, sex, smoking, family history) and body site.

Results

Analysis of within-subject coefficients of variation demonstrated that half of the participants had a middle spread [difference between 75^th and 25^th percentiles of the subject's abscess and nodule counts] greater than 33% and 40% of their median abscess and nodule counts, and 25% of the subjects had a middle spread greater than 70% and 78% of their median abscess and nodule counts in PIONEER I and II, respectively. Hurley stage 2 participants had significantly greater within-subject variation than Hurley stage 3 patients. Variation was greater in the axillary and groin regions than in other anatomical locations.

Limitations

Limitations include the use of precollected clinical trial data.

Conclusion

The within-subject variability of the lesion counts in untreated HS was greater than previously appreciated. This has profound effects on outcome measures and the conduct of future clinical trials of HS.

Metabolic Disorders/Obesity Is a Primary Risk Factor in Hidradenitis Suppurativa: An Immunohistochemical Real-World Approach

BACKGROUND

Hidradenitis suppurativa (HS) is an inflammatory, potentially scarring disease of the hair follicle, affecting the apocrine gland-bearing skin areas. The major comorbid disorders associated with the occurrence or the aggravation of the disease are obesity and smoking. Numerous efforts to dissociate these factors led to controversial results.

OBJECTIVES

To assess the importance of metabolic disorders/obesity, smoking/environmental toxins, and inflammation in HS by utilizing the differential expression of major relevant protein markers in lesional skin of obese/smoking versus non-obese/non-smoking HS patients.

METHODS

Lesional skin specimens deriving from two groups of HS patients (BMI >30 and smokers, n = 12 vs. BMI <30 and non-smokers, n = 10) were stained with antibodies raised against irisin, PPARγ, and IGF-1R, which correlate with metabolic disorders/obesity, EGFR and AhR, associated with smoking, and IL-17, IL-17R, and S100A8, as markers of inflammation.

RESULTS

Metabolic disorders/obesity-related markers exhibited marked differential expression between the two groups, while smoking-associated markers a limited one. IL-17R expression was stronger in obese/smokers, and S100A8 staining exhibited intense strong immunoreactivity in both groups without significant difference.

CONCLUSIONS

The notion that obesity plays a role in HS development appears to be supported by the prominent regulation of the associated lesional biomarkers. Tobacco smoking might contribute less to HS than previously suspected.

Updated Treatment for Acne: Targeted Therapy Based on Pathogenesis

Previous approaches to acne management have focused on the four main factors implicated in acne, namely, androgen-mediated sebogenesis (considered integral to acne), hyperkeratinization, colonization with Cutibacterium acnes, and inflammation related to both innate and adaptive mechanisms. Recent advances have facilitated potential novel approaches to acne management, as the pathophysiology and the immunological aspects related to acne and wound healing have evolved. Particular targets that have been shown to be closely involved in acne pathophysiology and wound healing include interleukin (IL)-1β, IL-17, IL-23, and tumor necrosis factor alpha (TNFα). Biological antibodies targeting IL-1β, IL-17, IL-23, and TNFα could provide novel approaches for treating severe acne and related disorders. Acne is primarily a disease associated with sebogenesis. Monosaturated free acids are important components. Insulin growth factor 1 (IGF-1) promotes the proliferation and differentiation of sebocytes and IL-1β. Research into the microbiome may also provide insights into potential future therapeutic options for acne. Scars, both atrophic and hypertrophic, are common sequelae to acne. Risk factors associated with the development of acne scars include genetic, systemic, local, and lifestyle factors. Pro-inflammatory cytokines have been shown to play a crucial role in the development of acne-induced hypertrophic scars. Treatment for extensive inflammatory keloid scarring is limited. Surgery and postoperative radiotherapy are two possible options. Transforming growth factor-β (TGFβ), IL-6, matrix metalloproteinase (MMP), IGF-1, and B cells are found in keloid or hypertrophic scar tissues. Biological antibodies targeting these cytokines may be a potential strategy for the prevention and treatment of this type of scar in the future. Future treatment for acne should embrace approaches that target the main etiological factors of acne. In particular, specific emphasis on aggressive treatment in the acute inflammatory phase to reduce the likelihood of scarring and other clinical sequelae, such as pigmentary changes would be highly desirable. Treatment for established acne-induced sequelae should also be considered.

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.

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.

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.

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 Forms of Tuberculosis in Patients with Inflammatory Bowel Diseases Treated with Biological Agents

Although there are undeniable advantages of treatment of the inflammatory bowel diseases, Crohn's disease, and ulcerative colitis, with biological agents, the increased susceptibility to tuberculosis should not be ignored. Tuberculosis is an infectious disease caused by the Mycobacterium tuberculosis complex which includes M. tuberculosis, M. bovis, and M. africanum. Primary tuberculosis is uncommon in the setting of inflammatory bowel disease: reactivation of latent tuberculosis is of greater concern. Consequently, latent infection should be excluded in patients who qualify for immunosuppressive treatments. Apart from the review of the literature, this article also presents three cases of different patterns of tuberculosis that occurred during treatment with infliximab, adalimumab, or vedolizumab. The first case reports a case of tuberculosis presenting as right middle lobe pneumonia. The second case featured miliary tuberculosis of the lungs with involvement of the mediastinal lymph nodes, liver, and spleen. The third patient developed a tuberculoma of the right parietal lobe and tuberculous meningitis. It is important to reiterate that every patient qualifying for a biologic agent should undergo testing to accurately identify latent tuberculosis, as well as precise monitoring for the possible development of one of the various forms or patterns of tuberculosis during treatment.

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.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Lipidomics Profiling of Hidradenitis Suppurativa Skin Lesions Reveals Lipoxygenase Pathway Dysregulation and Accumulation of Proinflammatory Leukotriene B4

Hidradenitis suppurativa (HS) is a chronic, recurring inflammatory dermatosis characterized by abscesses, deep-seated nodules, sinus tracts, and fibrosis in skin lesions around hair follicles of the axillary, inguinal, and anogenital regions. Whereas the exact pathogenesis remains poorly defined, clear evidence suggests that HS is a multifactorial inflammatory disease characterized by innate and adaptive immune components. Bioactive lipids are important regulators of cutaneous homeostasis, inflammation, and resolution of inflammation. Alterations in the lipid mediator profile can lead to malfunction and cutaneous inflammation. We used targeted lipidomics to analyze selected omega-3 and omega-6 polyunsaturated fatty acids in skin of patients with HS and of healthy volunteers. Lesional HS skin displayed enrichment of 5-lipoxygenase (LO)‒derived metabolites, especially leukotriene B4. In addition, 15-LO‒derived metabolites were underrepresented in HS lesions. Changes in the lipid mediator profile were accompanied by transcriptomic dysregulation of the 5-LO and 15-LO pathways. Hyperactivation of the 5-LO pathway in lesional macrophages identified these cells as potential sources of leukotriene B4, which may cause neutrophil influx and activation. Furthermore, leukotriene B4-induced mediators and pathways were elevated in HS lesions, suggesting a contribution of this proinflammatory lipid meditator to the pathophysiology of HS.

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.

Baseline patient-reported outcomes from UNITE: an observational, international, multicentre registry to evaluate hidradenitis suppurativa in clinical practice

Background

Hidradenitis suppurativa (HS) is a chronic, inflammatory, skin condition associated with many comorbidities and often has a substantial impact on patients’ lives.

Objectives

To evaluate symptom burden and health‐related quality of life (HRQoL) at baseline in patients with HS in an observational, real‐world, clinical setting using several tools including a validated HS‐specific instrument.

Methods

This study evaluated HRQoL data from the international UNITE HS disease registry. Administration of patient‐reported outcome (PRO) instruments and collection of data were executed per local regulations. All data were assessed using descriptive statistical methods.

Results

PRO data from 529 adults and 65 adolescents were evaluated. Most adults (64.5%) and adolescents (73.8%) were classified as Hurley Stage II with substantial disease burden at baseline. HS had a large effect (mean DLQI = 12.6) and moderate effect (mean CDLQI = 6.9) on the lives of adults and adolescents, respectively. Approximately 58% of adults and 41% of adolescents had anxiety scores beyond the normal range; 30% of adults and 16% of adolescents exhibited symptoms of depression. Based on HSSA and HSIA scores, approximately 30% of adults reported a substantial burden of multiple HS clinical symptoms and more than 45% reported a significant emotional impact of HS that adversely affected their intimate relationships. Only 60% of adults were employed and of those, 64% reported at least some degree of impairment while working because of HS.

Conclusions

Based on PROs collected from patients enrolled in the UNITE registry, a real‐world, clinical setting, HS has a significant negative impact on the everyday lives of patients affected by this disease.

The Role of the Cutaneous Microbiome in Hidradenitis Suppurativa-Light at the End of the Microbiological Tunnel

The development of next generation sequencing, coupled with advances in bio-informatics, has provided new insights into the role of the cutaneous microbiome in the pathophysiology of a range of inflammatory skin diseases. In fact, it has even been suggested that the identification of specific skin microbial signatures may not only be useful in terms of diagnosis of skin diseases but they may also ultimately help inform personalised treatment strategies. To date, research investigating the role of microbiota in the development of inflammatory skin diseases has largely focused on atopic eczema and psoriasis vulgaris. The role of the microbiome in Hidradenits suppurativa (HS)-also known as acne inversa-a chronic auto-inflammatory skin disease associated with significant morbidity, has received comparatively little attention. This is despite the fact that antimicrobial therapy plays a central role in the treatment of HS. After briefly outlining the clinical features of HS and current treatment strategies, we move on to review the evidence of microbial dysbiosis in HS pathophysiology. We conclude by outlining the potential for metagenomic studies to deepen our understanding of HS biology but more importantly to identify novel and much needed treatment strategies.

Alterations in innate immunity and epithelial cell differentiation are the molecular pillars of hidradenitis suppurativa

BACKGROUND

The large unmet need of hidradenitis suppurativa/acne inversa (HS) therapy requires the elucidation of disease-driving mechanisms and tissue targeting.

OBJECTIVE

Robust characterization of the underlying HS mechanisms and detection of the involved skin compartments.

METHODS

Hidradenitis suppurativa/acne inversa molecular taxonomy and key signalling pathways were studied by whole transcriptome profiling. Dysregulated genes were detected by comparing lesional and non-lesional skin obtained from female HS patients and matched healthy controls using the Agilent array platform. The differential gene expression was confirmed by quantitative real-time PCR and targeted protein characterization via immunohistochemistry in another set of female patients. HS-involved skin compartments were also recognized by immunohistochemistry.

RESULTS

Alterations to key regulatory pathways involving glucocorticoid receptor, atherosclerosis, HIF1α and IL17A signalling as well as inhibition of matrix metalloproteases were detected. From a functional standpoint, cellular assembly, maintenance and movement, haematological system development and function, immune cell trafficking and antimicrobial response were key processes probably being affected in HS. Sixteen genes were found to characterize HS from a molecular standpoint (DEFB4, MMP1, GJB2, PI3, KRT16, MMP9, SERPINB4, SERPINB3, SPRR3, S100A8, S100A9, S100A12, S100A7A (15), KRT6A, TCN1, TMPRSS11D). Among the proteins strongly expressed in HS, calgranulin-A, calgranulin-B and serpin-B4 were detected in the hair root sheath, koebnerisin and connexin-32 in stratum granulosum, transcobalamin-1 in stratum spinosum/hair root sheath, small prolin-rich protein-3 in apocrine sweat gland ducts/sebaceous glands-ducts and matrix metallopeptidase-9 in resident monocytes.

CONCLUSION

Our findings highlight a panel of immune-related drivers in HS, which influence innate immunity and cell differentiation in follicular and epidermal keratinocytes as well as skin glands.

Interleukin-23 pathway at the enthesis: The emerging story of enthesitis in spondyloarthropathy

The inflammatory disorders collectively termed the seronegative spondyloarthropathies (SpA) include ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis, the arthritis associated with inflammatory bowel disease including Crohn's disease and ulcerative colitis, the arthritis related to anterior uveitis, and finally, somewhat controversially Behcet's disease. All of these diseases are associated with SNPs in the IL-23R or the interleukin-23 (IL-23) cytokine itself and related downstream signaling JAK pathway genes and the interleukin-17 (IL-17) pathway. In rheumatoid arthritis, the target of the immune response is the synovium but the SpA disorders target the tendon, ligament, and joint capsule skeletal anchorage points that are termed entheses. The discovery that IL-23R-expressing cells were ensconced in healthy murine enthesis, and other extraskeletal anchorage points including the aortic root and the ciliary body of the eye and that systemic overexpression of IL-23 resulted in a severe experimental SpA, confirmed a fundamentally different immunobiology to rheumatoid arthritis. Recently, IL-23R-expressing myeloid cells and various innate and adaptive T cells that produce IL-17 family cytokines have also been described in the human enthesis. Blockade of IL-23 pathway with either anti-p40 or anti-p19 subunits has resulted in some spectacular therapeutic successes in psoriasis and PsA including improvement in enthesitis in the peripheral skeleton but has failed to demonstrate efficacy in AS that is largely a spinal polyenthesitis. Herein, we discuss the known biology of IL-23 at the human enthesis and highlight the remarkable emerging story of this unique skeletal tissue.

Race and Ethnicity Gaps in Global Hidradenitis Suppurativa Clinical Trials

BACKGROUND

Hidradenitis suppurativa (HS) is an often-debilitating disease characterized by chronic and recurrent painful nodules, abscesses, and sinus tracts affecting the intertriginous areas. Despite evidence in the literature of varying prevalence of HS among different racial and ethnic groups, no studies have evaluated the overall generalizability of clinical trial results considering the increased prevalence of HS among African American populations. Additionally, there is a paucity of data exploring the distribution of race and ethnicity in randomized controlled trials (RCTs) for HS. The goal of this analysis is to explore the distribution of race and ethnicity in recent HS RCTs.

SUMMARY

Using ClinicalTrials.gov and PubMed, race and ethnicity demographics were extracted from phase II and III trials published from 2000 to August 2019. Fifteen trials were included and among these trials 669 (68.0%) participants were Caucasian and 138 (14.0%) were of African descent. Asians, American Indian or Alaskan Natives, and Native Hawaiian or other Pacific Islanders comprised 29 (2.9%), 3 (0.3%), and 1 (0.1%) participant respectively. Only 15 participants were reported as Hispanic as only three trials reported ethnicity data. The remaining 144 (14.6%) participants were recorded as "other/unspecified" (36 self-identified, 108 lacked race reporting). None of the trials included sub-analysis of treatment efficacy based on race or ethnicity.

Role of the Complement Pathway in Inflammatory Skin Diseases: A Focus on Hidradenitis Suppurativa

Although the role of immune dysregulation in hidradenitis suppurativa (HS) has yet to be elucidated, recent studies identified several complement abnormalities in patients with HS. The complement system serves a critical role in the modulation of immune response and regulation of cutaneous commensal bacteria. Complement is implicated in several inflammatory skin diseases including systemic lupus erythematosus, angioedema, pemphigus, bullous pemphigoid, and HS. A model of HS pathogenesis is proposed, integrating the role of commensal bacteria, cutaneous immune responses, and complement dysregulation. The role of complement in disease pathogenesis has led to the development of novel anticomplement agents and clinical trials investigating the efficacy of such treatments in HS.

A Comparison of International Management Guidelines for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory dermatosis that imparts a significant burden on patients and presents a management challenge for healthcare providers. As attention to this debilitating condition has grown over recent years, our understanding of HS pathogenesis and optimal treatment approaches continues to evolve. Nine HS treatment guidelines developed by various expert organizations have been published, encompassing therapeutic modalities ranging from topical agents to systemic therapies to procedural interventions. These guidelines demonstrate significant overlap in treatment recommendations and have all been published within the last 5 years. Therefore, we aim to compare and synthesize the recommendations of international HS treatment guidelines and to encourage inter-organizational communication for the development of consensus or staggered publication of recommendations for HS management.

Hidradenitis suppurativa: Current and emerging treatments

The treatment of hidradenitis suppurativa (HS) has remained challenging because of the many knowledge gaps regarding etiology. However, recent studies into the pathogenesis of HS have enabled the investigation of newer therapies. The second article in this continuing medical education series reviews the evidence for established therapies for HS, including anti-inflammatories, antibiotics, and surgery. New and emerging therapies that specifically target cytokines involved in HS pathogenesis will be covered. The potential therapeutic roles of anticytokine therapies, including both the expanded application of existing molecules as well as the specific development of novel therapies for HS are discussed. With increased attention on HS and with numerous clinical trials currently underway, we hope that the variety of treatment options for HS will be expanded.

Biologic Treatment for Hidradenitis Suppurativa

Patients with hidradenitis suppurativa (HS) are often undertreated and there are limited efficacious therapies available for treating this population. Biologics are an emerging therapeutic modality used in the management of many inflammatory conditions including HS. Implementation of biologics is typically reserved for moderate-to-severe cases or in those cases that are refractory to treatment. Though many biologics have been trialed for use in HS, only one biologic, adalimumab, is currently US FDA (Food and Drug Administration) approved for the treatment of moderate-to-severe HS. Limitations in the use of biologics for HS include the many scoring systems utilized in research studies and the relatively few well-designed, adequately powered clinical trials.

Treatment of Hidradenitis Suppurativa Patient with Klinefelter Syndrome by Adalimumab

Hidradenitis suppurativa (HS) is a chronic, inflammatory and painful skin disease with recurrent nodules and tracts involving the intertriginous regions. It is known that the patient with HS shows an increased risk of metabolic disorders such as diabetes, metabolic syndrome and autoimmune diseases. Klinefelter syndrome (KS) is a sex chromosomal disorder occurring in males due to an abnormality of sexual differentiation, characterized by 47, XXY karyotype. Also, KS is related with somatic comorbidities such as metabolic syndrome, autoimmune and rheumatologic disorders as HS is. We report a HS patient with KS who shows a big improvement while on tumor necrosis factor-alpha inhibitor treatment.

The Safety and Impact of a Model of Intermittent, Time-Restricted Circadian Fasting ("Ramadan Fasting") on Hidradenitis Suppurativa: Insights from a Multicenter, Observational, Cross-Over, Pilot, Exploratory Study

Hidradenitis suppurativa (HS) is a chronic-relapsing and debilitating disease, which affects the components of the folliculopilosebaceous unit and severely impacts on the perceived health-related quality of life. Among the possible treatments, dietary interventions, such as fasting, have been described to positively impact on HS. However, nothing is known about the effects of circadian, intermittent fasting, such as the Ramadan fasting. A sample of 55 HS patients (24 males (43.6%) and 31 females (56.4%), mean age 39.65 ± 8.39 years, average disease duration 14.31 ± 7.03 years) was recruited in the present study. The “Severity of International Hidradenitis Suppurativa Severity Score System” (IHS4) decreased significantly from 11.00 ± 5.88 (before Ramadan) to 10.15 ± 6.45 (after Ramadan), with a mean difference of −0.85 ± 0.83 (p < 0.0001). At the univariate analyses, the improvement was associated with HS phenotype (with a prominent improvement among those with ectopic type), treatment (with the improvement being higher in patients receiving topical and systemic antibiotics compared to those treated with biologics), the “Autoinflammatory Disease Damage Index” (ADDI), and Hurley scores. At the multivariate regression analysis, only the Hurley score (regression coefficient = 0.70, p = 0.0003) was found to be an independent predictor of change in the IHS4 score after fasting. The improvement in the IHS4 score was not, however, associated with weight loss. In conclusion, the Ramadan fasting proved to be safe and effective in HS patients. Considering the small sample size and the exploratory nature of the present investigation, further studies in the field are warranted, especially longitudinal, prospective and randomized ones.

Topical, systemic and biologic therapies in hidradenitis suppurativa: pathogenic insights by examining therapeutic mechanisms

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin, manifesting in chronic, recurrent painful pustules, nodules, boils and purulent draining abscesses. Our current understanding of the pathogenesis of the disease is incomplete. This review aims to identify available treatment options in HS and discuss the pharmacological mechanisms through which such agents function. Identifying common pathways may inform our understanding of the pathogenesis of HS as well as identify future therapeutic targets. The pharmacological mechanisms implicated in topical therapies, antibiotic, hormonal, systemic immunomodulatory and biologic therapies for HS are discussed. Significant differences exist between agents and implicated pathways in therapy for mild and severe disease. This is an expression of the possible dichotomy in inflammatory pathways (and treatment responses) in HS. Studies involving monoclonal antibodies provide the greatest insight into what these specific mechanisms may be. Their variable levels of clinical efficacy compared with placebo bolsters the suggestion that differential inflammatory pathways may be involved in different presentations and severity of disease. Nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and other innate immune mechanisms are strongly represented in treatments which are effective in mild to moderate disease in the absence of scarring or draining fistulae, however complex feed-forward mechanisms in severe disease respond to interleukin (IL)-1 inhibition but are less likely to respond to innate immune inhibition (through NF-κB or TNF-α) alone. It is unclear whether IL-17 inhibition will parallel TNF-α or IL-1 inhibition in effect, however it is plausible that small molecule targets (Janus kinase1 and phosphodiesterase 4) may provide effective new strategies for treatment of HS.

T helper 17 cell/regulatory T-cell imbalance in hidradenitis suppurativa/acne inversa: the link to hair follicle dissection, obesity, smoking and autoimmune comorbidities

BACKGROUND

Disintegration of the infundibula of terminal hair follicles (HFs) in intertriginous skin areas exhibits the histological hallmark of hidradenitis suppurativa (HS)/acne inversa, featuring a dissecting terminal hair folliculitis. Elevated serum levels of interleukin (IL)-17 and local increase in the ratio of proinflammatory T helper (Th)17 cells and anti-inflammatory regulatory T cells (Tregs) have been reported. Perifollicular Tregs play a key role in HF stem cell homeostasis and infundibular integrity.

OBJECTIVES

In this review, we evaluate the Th17/Treg ratio in HS, its aggravating conditions and associated comorbidities. Furthermore, we intended to clarify whether drugs with reported beneficial effects in the treatment of HS readjust the deviated Th17/Treg axis.

METHODS

PubMed-listed, peer-reviewed original research articles characterizing Th17/Treg regulation in HS/acne inversa and associated comorbidities were selected for this review.

RESULTS

This review presents HS as a disease that exhibits an increased Th17/Treg ratio. Perifollicular deficiencies in Treg numbers or function may disturb HF stem cell homeostasis, initiating infundibular dissection of terminal HFs and perifollicular inflammation. The Th17/Treg imbalance is aggravated by obesity, smoking and decreased Notch signalling. In addition, HS-associated autoimmune diseases exhibit a disturbed Th17/Treg axis resulting in a Th17-dominant state. All drugs that have beneficial effects in the treatment of HS normalize the Th17/Treg ratio.

CONCLUSIONS

HS immunopathogenesis is closely related to deviations of the Th17/Treg balance, which may negatively affect Treg-controlled HF stem cell homeostasis and infundibular integrity. Pharmacological intervention should not only attenuate Th17/IL-17 signalling, but should also improve Treg function in order to stabilize HF stem cell homeostasis and infundibular integrity.

Adverse reactions of sorafenib, sunitinib, and imatinib in treating digestive system tumors

Background

This study was conducted to assess the adverse reactions caused by multi‐target tyrosine kinase inhibitor treatment of gastrointestinal tumors.

Methods

We carried out a retrospective study of drug‐related adverse reactions in 115 patients who were treated with sorafenib, sunitinib, and imatinib for primary hepatocellular carcinoma or gastrointestinal stromal tumors from October 2003 to March 2012 at the Peking University International Hospital.

Results

The total incidence of adverse reactions of sorafenib, sunitinib, and imatinib in patients with hepatocellular carcinoma and gastrointestinal stromal tumors was > 80%. The main adverse reactions of sorafenib were hypertension in 38 patients (33.3%) and diarrhea in 28 patients (24.4%). Sunitinib was associated with higher incidence and greater grade 3–4 toxicity. The common toxicities were skin color changes in 105 patients (90.9%), hand‐foot skin reactions in 65 patients (54.6%), and leukopenia (63.6%), hypertension (22.7%), proteinuria (22.7%), liver function impairment (22.7%), and hypomagnesemia (27.3%). While imatinib was well tolerated, it was associated with the highest number of adverse reactions, including skin color change (55.6%) and edema (38.9%). Hypophosphatemia (4.4%) and hoarseness (2.2%) only occurred in the sorafenib treatment group.

Conclusions

The adverse reactions of multi‐target tyrosine kinase inhibitor treatments are generally mild to moderate, and most patients can tolerate these without the need for further intervention. Some serious adverse reactions may be alleviated by discontinuing the drugs or by administering symptomatic treatment.