A spatial portrait of the human sebaceous gland transcriptional program.

Sebaceous glands (SG) and their oily secretion (sebum) are indispensable for maintaining skin structure and function, and their deregulation causes skin disorders including but not limited to acne. Recent studies also indicate that sebum may have important immunomodulatory activities and may influence whole-body energy metabolism. However, the progressive transcriptional changes of sebocytes that lead to sebum production have never been characterized in detail. Here, we exploited the high cellular resolution provided by sebaceous hyperplasia and integrated spatial transcriptomics, pseudo time analysis, RNA velocity, and functional enrichment to map the landscape of sebaceous differentiation. Our results were validated by comparison with published SG transcriptome data and further corroborated by assessing the protein expression pattern of a subset of the transcripts in the public repository Human Protein Atlas. Departing from four sebocyte differentiation stages generated by unsupervised clustering, we demonstrate consecutive modulation of cellular functions associable with specific gene sets, from cell proliferation and oxidative phosphorylation via lipid synthesis to cell death. Both validation methods confirmed the biological significance of our results. Our report is complemented by a freely available and browsable online tool. Our data provide the first high-resolution spatial portrait of the SG transcriptional landscape and deliver starting points for experimentally assessing novel candidate molecules for regulating SG homeostasis in health and disease.

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

BACKGROUND: Patients with hidradenitis suppurativa have substantial unmet clinical needs and scarce therapeutic options. We aimed to assess the efficacy and safety of bimekizumab, a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F and IL-17A, in patients with moderate-to-severe hidradenitis suppurativa. METHODS: BE HEARD I and II were two identically designed, 48-week randomised, double-blind, placebo-controlled, multicentre phase 3 trials. Patients aged 18 years or older with moderate-to-severe hidradenitis suppurativa were randomly assigned 2:2:2:1 using interactive response technology (stratified by worst Hurley Stage at baseline and baseline systemic antibiotic use) to receive subcutaneous bimekizumab 320 mg every 2 weeks; bimekizumab 320 mg every 2 weeks to week 16, then every 4 weeks to week 48; bimekizumab 320 mg every 4 weeks to week 48; or placebo to week 16, then bimekizumab 320 mg every 2 weeks. The primary outcome was an hidradenitis suppurativa clinical response of at least 50%, defined as a reduction in total abscess and inflammatory nodule count of at least 50% from baseline with no increase from baseline in abscess or draining tunnel count (HiSCR50) at week 16. Efficacy analyses included all randomly assigned study patients (intention-to-treat population). Safety analyses included all patients who received at least one full or partial dose of study treatment in the safety set, and of bimekizumab in the active-medication set. These trials are registered at ClinicalTrials.gov, NCT04242446 and NCT04242498, and both are completed. FINDINGS: Patients for BE HEARD I were recruited from Feb 19, 2020, to Oct 27, 2021, and 505 patients were enrolled and randomly assigned. Patients for BE HEARD II were recruited from March 2, 2020, to July 28, 2021, and 509 patients were enrolled and randomly assigned. The primary outcome at week 16 was met in the group who received bimekizumab every 2 weeks using modified non-responder imputation; higher responder rates were observed with bimekizumab versus placebo in both trials: 138 (48%) of 289 patients versus 21 (29%) of 72 patients in BE HEARD I (odds ratio [OR] 2·23 [97·5% CI 1·16-4·31]; p=0·0060) and 151 (52%) of 291 patients versus 24 (32%) of 74 patients in BE HEARD II (2·29 [1·22-4·29]; p=0·0032). In BE HEARD II, HiSCR50 was also met in the group who were administered bimekizumab every 4 weeks (77 [54%] of 144 vs 24 [32%] of 74 with placebo; 2·42 [1·22-4·80]; p=0·0038). Responses were maintained or increased to week 48. Serious treatment-emergent adverse events were reported in 40 (8%) patients in BE HEARD I and in 24 (5%) patients in BE HEARD II treated with bimekizumab over 48 weeks. The most frequently reported treatment-emergent adverse events to week 48 were hidradenitis in both trials, in addition to coronavirus infection and diarrhoea in BE HEARD I, and oral candidiasis and headache in BE HEARD II. One death was reported across the two trials, and was due to congestive heart failure in a patient with substantial cardiovascular history treated with bimekizumab every 2 weeks in BE HEARD I (considered unrelated to bimekizumab treatment by the investigator). No new safety signals were observed. INTERPRETATION: Bimekizumab was well tolerated by patients with hidradenitis suppurativa and produced rapid and deep clinically meaningful responses that were maintained up to 48 weeks. Data from these two trials support the use of bimekizumab for the treatment of patients with moderate-to-severe hidradenitis suppurativa. FUNDING: UCB Pharma.

Exosomes from adipose-derived stem cells activate sebocytes through the PI3K/AKT/SREBP-1 pathway to accelerate wound healing.

Sebocyte regeneration after injury is considered a key element of functional skin repair. Exosomes from adipose-derived stem cells (ADSCs-EXO) accelerate wound healing by promoting the proliferation of fibroblasts. However, the effects of ADSCs-EXO on sebocytes are largely unknown. In this study, the effects of ADSCs-EXO on sebocyte proliferation and migration were evaluated. The levels of phosphorylated AKT (p-AKT), AKT, sterol regulatory-element binding protein (SREBP), and perilipin-1 (PLIN-1) were detected with immunofluorescence, quantitative PCR, and western blot analysis. RNA-Seq was used to analyze the differential gene expression between the ADSCs-EXO group and the control group under anaerobic conditions. Lipogenesis was assessed with Nile red staining. In animal studies, full-thickness skin wounds in BALB/c mice were treated with gelatin methacrylate (GelMA) hydrogel-loaded sebocytes alone or in combination with ADSCs-EXO. Histopathological assessments of the wound tissues were performed Masson Trichrome staining, Immunohistochemical staining and so on. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway blocker LY294002 inhibited the effects of ADSCs-EXO on p-AKT and sebocytes proliferation. ADSCs-EXO also regulated the expression of SREBP-1 and PLIN-1 through the PI3K/AKT pathway in an oxygen level-dependent manner. In BALB/c mice, ADSCs-EXO accelerated sebocyte-assisted wound healing and regeneration. These in vitro and in vivo results supported that ADSCs-EXO can promote the regeneration of fully functional skin after injury through the PI3K/AKT-dependent activation of sebocytes.

Secukinumab in patients with moderate-to-severe hidradenitis suppurativa based on prior biologic exposure: an efficacy and safety analysis from the SUNSHINE and SUNRISE phase III trials.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with a substantial disease burden. Secukinumab has previously been reported to have sustained efficacy with a favourable safety profile in patients with moderate-to-severe HS. It is unknown whether prior biologic exposure affects the efficacy and safety of secukinumab. OBJECTIVES: To investigate the efficacy and safety of secukinumab in patients with moderate-to-severe HS based on prior exposure to -biologics. METHODS: This was an analysis of the SUNSHINE and SUNRISE phase III trials of secukinumab in patients with moderate-to-severe HS. Patients were randomized at baseline to receive secukinumab every 2 (SECQ2W) or 4 weeks (SECQ4W), or placebo for 16 weeks. After week 16, patients on the SECQ2W and SECQ4W schedules remained on the same treatment regimen, while patients randomized to placebo were switched to either SECQ2W or SECQ4W up to week 52. Assessments based on prior exposure to biologics included Hidradenitis Suppurativa Clinical Response (HiSCR), abscess and inflammatory nodule (AN) count, flare rates, HS-related pain [numerical rating scale 30 (NRS30)], 55% reduction in the International Hidradenitis Suppurativa Severity Score System (IHS4-55), Dermatology Life Quality Index, EuroQol-5D and safety. RESULTS: Overall, 1084 patients were randomized in the SUNSHINE and SUNRISE trials and included in this analysis; 255 (23.5%) were biologic-experienced [SECQ2W (n = 80); SECQ4W (n = 81); placebo (n = 94)] and 829 (76.5%) were biologic-naïve [SECQ2W (n = 281); SECQ4W (n = 279); placebo (n = 269)]. At week 16, responses were more efficacious for secukinumab than for placebo with regard to HiSCR in patients who were biologic-experienced {SECQ2W 37.0% [odds ratio (OR) 1.60, 95% confidence interval (CI) 0.83-3.08]; SECQ4W 38.8% [OR 1.67, 95% CI 0.86-3.22]; placebo 27.3%} and biologic-naïve [SECQ2W 45.6% (OR 1.64, 95% CI 1.15-2.33); SECQ4W 45.4% (OR 1.61, 95% CI 1.13-2.29); placebo 34.2%]. Similar results were observed for AN count, NRS30 and IHS4-55. The higher response seen at week 16 with secukinumab was sustained, with a trend toward improvement over time, through to week 52 in both subgroups. Additional efficacy was observed for quality-of-life assessments, and no differences in safety between subgroups were observed. CONCLUSIONS: Regardless of prior biologic exposure, secukinumab was efficacious in improving the signs and symptoms of HS. This finding positions secukinumab as the first option in patients who are biologic-naïve, as well as in patients who have previously been treated with other biologic therapy, based on individual patient needs.

Hidradenitis suppurativa (HS) is a chronic skin disease that causes painful boils. HS is common and affects about 0.4% of the world's population. Treating the condition is difficult, but drugs called 'biologics' can help to improve the symptoms. For example, secukinumab is a biologic drug that has been shown to be effective and well-tolerated for the treatment of HS. In this analysis, we investigated whether previous treatment with biologics could affect the effectiveness and tolerability of secukinumab. This analysis included data from two identical clinical trials (called SUNSHINE and SUNRISE) that recruited adult patients with HS who had moderate-to-severe disease. In these trials, patients took secukinumab 300 mg every 2 weeks or every 4 weeks for 1 year, or a placebo for 4 months and then switched to secukinumab until 1 year. At regular intervals, the effectiveness and tolerability of secukinumab were examined and the results were compared between patients who had previously used another biologic and patients who had never used a biologic before. After 16 weeks, patients who took secukinumab had better results than the patients who took a placebo, independent of previous biologic use. Secukinumab was still effective and had improved results over 1 year of treatment in both subgroups. Regardless of whether patients had previously been taking another biologic, secukinumab was just as tolerable as placebo and there were no new safety risks. Our analysis shows that secukinumab is effective and tolerable, regardless of whether patients have previously used another biologic drug.

Proof-of-concept study exploring the effect of spesolimab in patients with moderate-to-severe hidradenitis suppurativa: A randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a considerable disease burden. Existing treatment options are limited and often suboptimal; a high unmet need exists for effective targeted therapies. OBJECTIVE: To explore the effects of spesolimab treatment in patients with HS. METHODS: This randomized, double-blind, placebo-controlled, proof-of-clinical-concept study was conducted at 25 centers across 12 countries from May 3, 2021, to April 21, 2022. Patients had moderate-to-severe HS for ≥1 year before enrollment. Patients were randomized (2:1) to receive a loading dose of 3600 mg intravenous spesolimab (1200 mg at Weeks 0, 1, and 2) or matching placebo, followed by maintenance with either 1200 mg subcutaneous spesolimab every 2 weeks from Week 4-10 or matching placebo. The primary endpoint was the percentage change from baseline in total abscess and inflammatory nodule (AN) count at Week 12. Secondary endpoints were the absolute change from baseline in International Hidradenitis Suppurativa Severity Score System (IHS4), percentage change from baseline in draining tunnel (dT) count, the proportion of patients achieving a dT count of zero, absolute change from baseline in revised Hidradenitis Suppurativa Area and Severity Index (HASI-R), the proportion of patients achieving Hidradenitis Suppurativa Clinical Response (HiSCR50), the proportion of patients with ≥1 flare (all at Week 12), and patient-reported outcomes (PROs). RESULTS: In this completed trial, randomized patients (N=52) received spesolimab (n=35) or placebo (n=17). The difference (95% confidence interval) versus placebo in least squares mean are reported. At Week 12, the percentage change in total AN count was similar between treatment arms: -4.1% (-31.7, 23.4). There was greater numerical improvement in the spesolimab arm, as measured by IHS4: -13.9 (-25.6, -2.3); percentage change from baseline in dT count: -96.6% (-154.5, -38.8); and the proportion of patients achieving a dT count of zero: 18.3% (-7.9, 37.5). Spesolimab treatment also improved HASI-R and HiSCR50 versus placebo. Spesolimab demonstrated a favorable safety profile, similar to that observed in trials in other diseases. CONCLUSIONS: This exploratory proof-of-clinical-concept study supports the development of spesolimab as a new therapeutic option in HS. ClinicalTrials.gov identifier: NCT04762277.

Efficacy and safety of the oral Janus kinase 1 inhibitor povorcitinib (INCB054707) in patients with hidradenitis suppurativa in a phase 2, randomized, double-blind, dose-ranging, placebo-controlled study.

BACKGROUND: Janus kinase 1 inhibition may alleviate hidradenitis suppurativa (HS)-associated inflammation and improve symptoms. OBJECTIVE: To assess efficacy and safety of povorcitinib (selective oral Janus kinase 1 inhibitor) in HS. METHODS: This placebo-controlled phase 2 study randomized patients with HS 1:1:1:1 to receive povorcitinib 15, 45, or 75 mg or placebo for 16 weeks. Primary and key secondary end points were mean change from baseline in abscess and inflammatory nodule count and percentage of patients achieving HS Clinical Response at week 16. RESULTS: Of 209 patients randomized (15 mg, n = 52; 45 mg, n = 52; 75 mg, n = 53; placebo, n = 52), 83.3% completed the 16-week treatment. At week 16, povorcitinib significantly reduced abscess and inflammatory nodule count from baseline (least squares mean [SE] change: 15 mg, -5.2 [0.9], P = .0277; 45 mg, -6.9 [0.9], P = .0006; 75 mg, -6.3 [0.9], P = .0021) versus placebo (-2.5 [0.9]). More povorcitinib-treated patients achieved HS Clinical Response at week 16 (15 mg, 48.1%, P = .0445; 45 mg, 44.2%, P = .0998; 75 mg, 45.3%, P = .0829) versus placebo (28.8%). A total of 60.0% and 65.4% of povorcitinib- and placebo-treated patients had adverse events. LIMITATIONS: Baseline lesion counts were mildly imbalanced between groups. CONCLUSION: Povorcitinib demonstrated efficacy in HS, with no evidence of increased incidence of adverse events among doses.

The Global Hidradenitis Suppurativa Atlas Methodology: Combining Global Proportions in a Pooled Analysis.

INTRODUCTION: Data concerning the global burden of hidradenitis suppurativa (HS) are limited. Reported prevalence estimates vary between 0.0003% and 4.1%, and data from various geographical regions are still to be collected. Previously reported prevalences have been limited by the methodological approach and source of data. This has resulted in great heterogeneity as prevalence data from physician-diagnosed cases poorly match those of self-reported apparent HS disease. METHODS: The Global Hidradenitis Suppurativa Atlas (GHiSA) introduces an innovative approach to determine the global prevalence of HS. This approach involves using a previously validated questionnaire to screen apparently healthy adults accompanying a patient to a non-dermatological outpatient clinic visit in a hospital or a private/family medicine clinic. The screening questionnaire (i.e., the index test) is combined with a subsequent physician-based in-person validation (i.e., the reference standard) of the participants who screen positive. Approximately ten percent of the screen-negative participants are also clinically assessed to verify the diagnostic precision of the test. The local prevalence (pi) will be estimated from each country that submits the number of patients who are HS positive according to the index test and clinical examination (n), and the corresponding total number of observations (N). CONCLUSION: The GHiSA Global Prevalence studies are currently running simultaneously in 58 countries across six continents (Africa, Europe, Australia, North America, South America, and Asia). The goal of the combined global proportion is the generation of a single summary (i.e., proportional meta-analysis), which will be done after a logit transformation and synthesized using a random-effects model. The novel standardization of the Global Prevalence Studies conducted through GHiSA enables direct international comparisons, which were previously not possible due to substantial heterogeneity in past HS prevalence studies.

Isotretinoin-associated acne fulminans: A multicentre, retrospective study of the European Academy of Dermatology and Venereology Task Force on Acne, Rosacea and Hidradenitis Suppurativa.

BACKGROUND: Acne fulminans (AF) is a rare severe acne entity. Although occasionally reported, it is unclear whether AF development is associated with oral isotretinoin treatment. OBJECTIVES: To investigate the occurrence of isotretinoin-associated AF, clinical characteristics and prognosis at follow-up. METHODS: An international, multicentre, retrospective study was performed in eight hospitals following the call of the EADV Task Force on Acne, Rosacea and Hidradenitis Suppurativa (ARHS). Characteristics of patients treated with isotretinoin before the development of AF (isotretinoin-associated acne fulminans, IAF) were compared with non-IAF (NAF). RESULTS: Forty-nine patients diagnosed with AF from 2008 to 2022 were included (mean age 16.4 years, SD 2.9, 77.6% male). Αrthralgias/arthritis occurred in 11 patients (22.9%). AF occurred without any previous acne treatment in 26.5% of the patients. Overall, 28 patients (57.1%) developed AF after oral isotretinoin intake (IAF group), while the remaining 21 patients (42.9%) developed AF without previous oral isotretinoin administration (NAF group). IAF occurred after a median duration of isotretinoin treatment of 45 days (IQR: 30, 90). Patients with IAF were more frequently male compared to patients with NAF (89.3% vs. 61.9%, respectively, p = 0.023). There were no differences in patients with IAF versus NAF in patient age, the duration of pre-existing acne, a family history of AF, the distribution of AF lesions or the presence of systemic symptoms or arthralgias. Regarding the management of AF, patients with IAF were treated more frequently with prednisolone (96.2%) compared to those with NAF (70%; p = 0.033) and less frequently with isotretinoin (32.1%) compared to NAF (85.7%; p < 0.001). At a median follow-up of 2.2 years, 76.4% of patients were free of AF and scarring was present in all patients. CONCLUSIONS: No specific clinical or demographic characteristics of IAF compared with NAF could be detected, a fact that does not support IAF as a district clinical entity.

Discrepancies in hidradenitis suppurativa lesion characterization by providers and patients.

BACKGROUND: The hidradenitis suppurativa (HS) clinical response (HiSCR) has come under scrutiny as several HS clinical trials failed to meet primary endpoints with high placebo responses. This may be due to limitations of the tool and raters' ability to accurately characterize and count lesions, rather than lack of efficacy of the studied drug. Due to HS lesion complexity and potential differences in rater training, it was hypothesized that there would be discrepancies in how providers characterize and count lesions for HS clinical trials. OBJECTIVE: To evaluate how HS providers and patients name and count HS lesions and to identify discrepancies among providers to initiate the development of consensus-driven guidance for HS rater training. METHODS: An online survey was distributed to the members of HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC). Respondents were asked to classify lesion images composed of multiple and different morphology types and answer questions regarding inclusion of associated dermatological conditions. RESULTS: Forty-seven HISTORIC members responded (29 providers; 18 patients). There was variability in how respondents classified HS lesions. Of 12 questions containing images, four had ≥50% of respondents choosing the same answer. With an image of a lesion composed of different morphologies, 45% of providers counted it as a single lesion and 45% counted it as multiple distinct lesions. With an image of multiple interconnected draining tunnels, 7% of providers classified it as a single draining tunnel while 79% categorized it as multiple draining tunnels with the number estimated by visual inspection. There was also variability in deciding whether lesions occurring in associated conditions should be considered separately or included in HS lesion counts. Patient responses were also variable. CONCLUSIONS: The result of the current study reaffirms the gap in how providers characterize and count HS lesions for clinical trials and the need to develop consensus-driven rater training related to HS outcome measures.

Sentinel lymph node biopsy is unreliable in predicting melanoma mortality for both younger and older patients.

BACKGROUND: Melanoma disease patterns vary with patient age. AIM: To evaluate sentinel lymph node biopsy (SLNB) in managing melanoma at differing patient ages. METHODS: Online prediction tools were applied to compare SLNB positivity (SLNB+) and survival risk at patient ages 20-80. Tübingen melanoma data were used to determine variations in the hazard ratio of SLNB+ for mortality at different patient ages. RESULTS: Regardless of tumour thickness, predicted SLNB+ rates were markedly higher than mortality rates for 20-year-old patients. For 80-year-old patients, it is the opposite. DISCUSSION: If 1000 20-year-olds with a 0.4 mm thickness non-ulcerated melanoma underwent SLNB, 100 would likely be positive. If all 100 were to be offered adjuvant drug therapy (ADT), fewer than three more melanoma deaths in those 1000 patients would be avoided. In total, 97 patients would have received medication they may never have needed. If 1000 80-year-olds with a 3 mm thickness non-ulcerated melanoma underwent SLNB, only 40 would likely be positive. In total, 274 patients would be predicted to die of melanoma, 245 being SLNB negative and 29 SLNB+. ADT linked to SLNB+ could deny treatment to 89% of these high-risk patients. LIMITATIONS: The authors relied on published risk data. CONCLUSION: SLNB has poor specificity at predicting mortality in young melanoma patients and poor sensitivity in older patients. SLNB is not indicated in managing cutaneous melanoma for patients under 40 or over 60 years of age. Many such patients could be managed with wide local excision alone in their clinician's office-based practice. For all cutaneous melanoma patients at all ages, linking ADT to BAUSSS biomarker, (an algorithm of Breslow thickness, age, ulceration, subtype, sex and Site) rather than SLNB+ is likely more appropriate. BAUSSS provides a more accurate melanoma-specific mortality risk assessment for patients without burdening them with added surgery, hospitalization, costs or morbidity risk.

Interleukins 4 and 13 drive lipid abnormalities in skin cells through regulation of sex steroid hormone synthesis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin dryness, inflammation, and itch. A major hallmark of AD is an elevation of the immune cytokines IL-4 and IL-13. These cytokines lead to skin barrier disruption and lipid abnormalities in AD, yet the underlying mechanisms are unclear. Sebaceous glands are specialized sebum-producing epithelial cells that promote skin barrier function by releasing lipids and antimicrobial proteins to the skin surface. Here, we show that in AD, IL-4 and IL-13 stimulate the expression of 3ß-hydroxysteroid dehydrogenase 1 (HSD3B1), a key rate-limiting enzyme in sex steroid hormone synthesis, predominantly expressed by sebaceous glands in human skin. HSD3B1 enhances androgen production in sebocytes, and IL-4 and IL-13 drive lipid abnormalities in human sebocytes and keratinocytes through HSD3B1. Consistent with our findings in cells, HSD3B1 expression is elevated in the skin of AD patients and can be restored by treatment with the IL-4Rα monoclonal antibody, Dupilumab. Androgens are also elevated in a mouse model of AD, though the mechanism in mice remains unclear. Our findings illuminate a connection between type 2 immunity and sex steroid hormone synthesis in the skin and suggest that abnormalities in sex steroid hormone synthesis may underlie the disrupted skin barrier in AD. Furthermore, targeting sex steroid hormone synthesis pathways may be a therapeutic avenue to restoring normal skin barrier function in AD patients.

S2k guideline for the treatment of hidradenitis suppurativa / acne inversa - Short version.

The S2k guideline on hidradenitis suppurativa/acne inversa (HS/AI) aims to provide an accepted decision aid for the selection/implementation of appropriate/sufficient therapy. HS/AI is a chronic recurrent, inflammatory, potentially mutilating skin disease of the terminal hair follicle-glandular apparatus, with painful, inflammatory lesions in the apocrine gland-rich regions of the body. Its point prevalence in Germany is 0.3%, it is diagnosed with a delay of 10.0 ± 9.6 years. Abnormal differentiation of the keratinocytes of the hair follicle-gland apparatus and accompanying inflammation form the central pathogenetic basis. Primary HS/AI lesions are inflammatory nodules, abscesses and draining tunnels. Recurrences in the last 6 months with at least 2 lesions at the predilection sites point to HS/AI with a 97% accuracy. HS/AI patients suffer from a significant reduction in quality of life. For correct treatment decisions, classification and activity assessment should be done with a validated tool, such as the International Hidradenitis Suppurativa Severity Scoring System (IHS4). HS/AI is classified into two forms according to the degree of detectable inflammation: active, inflammatory (mild, moderate, and severe according to IHS4) and predominantly inactive, non-inflammatory (Hurley grade I, II and III) HS/AI. Oral tetracyclines or 5-day intravenous therapy with clindamycin are equal to the effectiveness of clindamycin/rifampicin. Subcutaneously administered adalimumab, secukinumab and bimekizumab are approved for the therapy of HS/AI. Various surgical procedures are available for the predominantly non-inflammatory disease form. Drug/surgical combinations are considered a holistic therapy method.

12th European Hidradenitis Suppurativa (EHSF) e.V. Conference-Facing HS according to the Renessaince style.

The-first hybrid-12th Conference of the European Hidradenitis Suppurativa Foundation (EHSF) e.V. took place on 8-10 February 2023 in Florence, Italy. With 198 high level scientific contributions and 757 participants from 45 countries, this 12th EHSF e.V. Conference has already been added to the EHSF's most unforgettable scientific activities. Twenty two active contributors were scientists and students under the age of 30 years and concurred for the three Young Investigator Awards. This special issue of Experimental Dermatology includes extended abstracts of the majority of the scientific lectures and posters. The 13th EHSF Conference will take place on February 7-9, 2024, as a physical presence event in Lyon, France. Dr. Philippe Guillem, Prof. Axel Villani and their team are glad to become your hosts.

Desaturation of sebaceous-type saturated fatty acids through the SCD1 and the FADS2 pathways impacts lipid neosynthesis and inflammatory response in sebocytes in culture.

Sebum is a lipid-rich mixture secreted by the sebaceous gland (SG) onto the skin surface. By penetrating through the epidermis, sebum may be involved in the regulation of epidermal and dermal cells in both healthy and diseased skin conditions. Saturated and monounsaturated fatty acids (FAs), found as free FAs (FFAs) and in bound form in neutral lipids, are essential constituents of sebum and key players of the inflammatory processes occurring in the pilosebaceous unit in acne-prone skin. Little is known on the interplay among uptake of saturated FFAs, their biotransformation, and induction of proinflammatory cytokines in sebocytes. In the human SG, palmitate (C16:0) is the precursor of sapienate (C16:1n-10) formed by insertion of a double bond (DB) at the Δ6 position catalysed by the fatty acid desaturase 2 (FADS2) enzyme. Conversely, palmitoleate (C16:1n-7) is formed by insertion of a DB at the Δ9 position catalysed by the stearoyl coenzyme A desaturase 1 (SCD1) enzyme. Other FFAs processed in the SG, also undergo these main desaturation pathways. We investigated lipogenesis and release of IL-6 and IL-8 pro-inflammatory cytokines in SZ95 sebocytes in vitro after treatment with saturated FFAs, that is, C16:0, margarate (C17:0), and stearate (C18:0) with or without specific inhibitors of SCD1 and FADS2 desaturase enzymes, and a drug with mixed inhibitory effects on FADS1 and FADS2 activities. C16:0 underwent extended desaturation through both SCD1 and FADS2 catalysed pathways and displayed the strongest lipoinflammatory effects. Inhibition of desaturation pathways proved to enhance lipoinflammation induced by SFAs in SZ95 sebocytes. Palmitate (C16:0), margarate (C17:0), and stearate (C18:0) are saturated fatty acids that induce different arrays of neutral lipids (triglycerides) and dissimilar grades of inflammation in sebocytes.

Preservation of epidermal melanocyte integrity in an ex vivo co-culture skin model with sebocytes.

A direct contact co-culture of skin explants to SZ95 sebocytes (3D-SeboSkin) has been shown to preserve the integrity of epidermal keratinocytes and dermis. In this study, the properties of epidermal melanocytes were evaluated in the same 3D SeboSkin ex vivo model. Skin explants (n = 6) were maintained in the 3D-SeboSkin model, in direct contact to fibroblasts and alone in serum-free medium (SFM). Histopathological, immunohistochemical, apoptosis and oil red staining evaluations were performed at Days 0 and 6 of incubation. Results revealed preservation and prominent proliferation of basal keratinocytes of the skin explants in addition to preservation of dermal collagen and vasculature at Day 6 in the 3D-SeboSkin culture model and to a lesser extent in co-culture with fibroblasts but not in SFM alone. Melan-A+/Ki67- epidermal melanocytes remained attached to the dermis even at sites of epidermal detachment in the three skin explant models tested. However, the number of epidermal melanocytes was significantly conserved in 3D-SeboSkin cultures in comparison with skin explants in SFM (p < 0.05), whereas no difference was found in comparison with the co-culture with fibroblasts. Few DAPI/TUNEL+ apoptotic melanocytes could mostly be observed in SFM-incubated skin explants. Furthermore, only SZ95 sebocytes in contact to skin explants in 3D-SeboSkin exhibited increased lipogenesis with accumulation of abundant lipid droplets. These results denote that the 3D-SeboSkin model yielded significant preservation of epidermal melanocytes and hence it is optimal for ex vivo studies of abnormalities of skin pigmentation, melanocyte neoplasms and effects of different hormones, cytokines, carcinogens and various therapeutics in a pattern that recapitulates the in vivo environment.

Chronic Inflammatory Intestinal Disorders in Hidradenitis Suppurativa.

BACKGROUND: Intestinal symptoms are common in patients with hidradenitis suppurativa (HS). HS patients may experience a broad spectrum of chronic inflammatory intestinal disorders (CIID), not exclusive to inflammatory bowel diseases, which are diagnosed by colonoscopy and intestinal biopsies. The frequency of CIID in patients with HS has not been investigated. OBJECTIVE: The objectives of this study were to determine the occurrence of CIID in HS and characterize this clinical population. Furthermore, the feasibility of using faecal calprotectin (FC) test or anti-Saccharomyces cerevisiae antibody (ASCA) levels to assess the colonic inflammation of CIID in HS patients was investigated. METHODS: All newly diagnosed and untreated HS patients (n = 74) were referred to a gastroenterologist for FC followed by colonoscopy after informed consent. C-reactive protein (CRP), white blood cell count, nucleotide-binding oligomerization-domain-containing protein 2 (NOD2) polymorphism, and ASCA levels were measured. Patients were divided into HS-only and HS with CIID (HS + CIID) groups, based on the absence or presence of CIID. Laboratory and clinical parameters (age, gender, HS onset, clinical stage, family history, body mass index (BMI), smoking) were compared between the groups. RESULTS: Thirteen patients complained gastrointestinal symptoms prior to any examination, including 11 in the HS + CIID group. The CIID frequency in HS was 28.4% (n = 21/74), based on colonoscopy and histology. Significantly more patients had severe disease state in the HS + CIID group compared with the HS-only group, and BMI was significantly lower in the HS + CIID group (28.20 ± 5.58 vs. 32.74 ± 6.45, p = 0.006). FC positivity occurred significantly more in HS + CIID patients compared with HS-only patients (90.48% vs. 3.77%, p < 0.001), and ASCA IgG levels were significantly elevated in HS + CIID patients (22.08 ± 23.07 vs. 8.41 ± 10.94 U/mL, p = 0.001). The FC test identified HS + CIID patients with 96.23% specificity and 91.3% sensitivity, while ASCA displayed 77.8% sensitivity and 76.3% specificity. Blood count, CRP, and the presence of NOD2 polymorphisms were indifferent between the two groups. CONCLUSION: A high frequency of CIID was detected in the examined HS population. The noninvasive FC test has high sensitivity and specificity for diagnosing CIID in HS patients. Concomitant CIID and HS may indicate the need for an early-start for biological treatment.

Which Health-Related Quality of Life Items Most Affect Acne Patients?

BACKGROUND: Health-related quality of life (HRQoL) assessment in patients with acne is recommended by several national guidelines. There are several acne-specific HRQoL instruments. OBJECTIVES: Participants of the European Academy of Dermatology and Venereology (EADV) Task Forces (TFs) on QoL and Patient Oriented Outcomes (PO) and Acne, Rosacea, and Hidradenitis Suppurativa (ARHS) agreed to scrutinize aspects of existing acne-specific HRQoL instruments for their relevance in international study. METHODS: Consensus agreement on items related to QoL was reached after an independent assessment by seven experts from the EADV TFs on QoL and PO, and a list of 97 items was prepared and proposed to a group of acne patients. In order to have data from patients to check if any important topics were overseen, another group of acne patients from participating countries was asked to list how acne influenced different aspects of their lives. RESULTS: Based on results obtained from 601 acne patients from nine countries, most of the items and topics showed low relevance for acne patients especially during the previous month or shorter time periods. Based on percentage of relevance and factor analysis, short (6 items) and long (45 items) lists of the most relevant topics were formed. CONCLUSION: Most of the items and topics from the initial list showed low relevance for acne patients. None of the identified acne-specific HRQoL instruments contain all the items that were deemed most relevant to acne patients. For this reason, participating members of the EADV TFs on QoL and PO, and ARHs are in the process of developing a new acne-specific HRQoL instrument.

External Validation of the IHS4-55 in a European Antibiotic-Treated Hidradenitis Suppurativa Cohort.

BACKGROUND: Previously, a new dichotomous outcome was developed, calculated as 55% reduction in the International Hidradenitis Suppurativa 4 (IHS4-55) score. It was validated in datasets of adalimumab and placebo-treated HS patients. External validation is an important aspect of clinical outcomes. OBJECTIVES: We aimed to externally validate the novel dichotomous IHS4-55 in a non-biologic treated dataset of HS patients. METHODS: Data from a previously published European-wide prospective clinical study of antibiotic treatment of HS patients were used to assess the association of IHS4-55 achievement with individual reduction in inflammatory nodules, abscesses, and draining tunnels. Moreover, the associations between IHS4-55 positivity and achievement of the minimal clinically important differences (MCIDs) for Dermatology Life Quality Index (DLQI), Numerical Rating Scale (NRS) Pain, and NRS Pruritus were analyzed. RESULTS: Data were obtained from 283 individual patients, of which 36.4% (103/283) were treated with clindamycin and rifampicin and 63.6% (180/283) with tetracyclines for 12 weeks. Achievers of the IHS4-55 demonstrated a significant reduction the counts of inflammatory nodules, abscesses, and draining tunnels (all p < 0.001). Additionally, IHS4-55 achievers had an odds ratio for achieving the MCID of DLQI, NRS Pain, and NRS Pruritus of 2.16 (95% CI 1.28-3.65, p < 0.01), 1.79 (95% CI 1.10-2.91, p < 0.05), and 1.95 (95% CI 1.18-3.22, p < 0.01), respectively. CONCLUSIONS: This study shows the external validity of the novel IHS4-55 by demonstrating a significant association between IHS4-55 achievement and a reduction in inflammatory lesion counts as well as achievement of MCIDs for DLQI, NRS Pain, and NRS Pruritus in an antibiotic-treated cohort. These findings support the use of the IHS4-55 as a novel primary outcome measure in clinical trials.

Measuring Quality of Life in Hidradenitis Suppurativa: Development and Validation of a Disease-specific Patient-reported Outcome Measure for Practice and Research.

Hidradenitis suppurativa is a chronic disease that disrupts patients' physical and psychological well-being. A disease-specific measure was developed and validated for assessing health-related quality of life in hidradenitis suppurativa. After qualitative item development, the quality of life in hidradenitis suppurativa instrument was tested in 101 patients, applying convergent measures and a usability questionnaire. Descriptive and validation-specific analyses were conducted. There was no ceiling, but moderate floor effects (scores between 0 and 3.13 on a scale of 0-4). Few missing values were observed (21 of 23 items < 5%). Internal consistency was satisfying: 2 subscales with 6 and 16 items were identified (Cronbach's alpha=0.95 and 0.88). The quality of life in hidradenitis suppurativa instrument correlated significantly with all convergent criteria (including change in convergent patient-reported outcomes; p < 0.05) except for Hurley stage (p = 0.490). In conclusion, the quality of life in hidradenitis suppurativa questionnaire is an internally consistent, valid, responsive, and usable instrument to assess quality of life in patients with hidradenitis suppurativa.

Dendrimer-conjugated isotretinoin for controlled transdermal drug delivery.

BACKGROUND: In the present study, we aimed to develop a novel isotretinoin delivery model for treating skin diseases, revealing its potential advantages in drug delivery and targeted therapy. Using a self-assembly strategy, we grafted a dendrimer, based on a well-defined branched structure for nanomedical devices, with a well-defined nanoarchitecture, yielding spherical, highly homogeneous molecules with multiple surface functionalities. Accordingly, a self-assembled dendrimer-conjugated system was developed to achieve the transdermal delivery of isotretinoin (13cRA-D). RESULTS: Herein, 13cRA-D showed remarkable controlled release, characterized by slow release in normal tissues but accelerated release in tissues with low pH, such as sites of inflammation. These release characteristics could abrogate the nonteratogenic side effects of isotretinoin and allow efficient skin permeation. Moreover, 13cRA-D exhibited high therapeutic efficacy in acne models. Based on in vitro and in vivo experimental results, 13cRA-D afforded better skin penetration than isotretinoin and allowed lesion targeting. Additionally, 13cRA-D induced minimal skin irritation. CONCLUSION: Our findings suggest that 13cRA-D is a safe and effective isotretinoin formulation for treating patients with skin disorders.