Improved clinical effectiveness of adalimumab when initiated with clindamycin and rifampicin in hidradenitis suppurativa

BACKGROUND

Adalimumab monotherapy for hidradenitis suppurativa (HS) is often insufficient with a maximum clinical efficacy of 60% in Hidradenitis Suppurativa Clinical Response (HiSCR) and limited effect on draining tunnels. Data suggest that adalimumab therapy could be improved by concomitant antibiotics.

OBJECTIVE

To compare the clinical effectiveness of adalimumab with clindamycin and rifampicin versus adalimumab monotherapy after 12 weeks.

METHODS

This retrospective study included patients who started adalimumab with additional clindamycin and rifampicin and patients treated with adalimumab monotherapy, matched on sex and refined Hurley score. The primary outcome measure was the difference in change in the International Hidradenitis Suppurativa Severity Score System (IHS4) at 12 weeks.

RESULTS

In total, 62 patients were included in the combination therapy group (n = 31) and adalimumab monotherapy group (n = 31), showing comparable IHS4 scores; 32.5 versus 29, p = 0.87 at baseline respectively. The combination therapy demonstrated greater clinical effectiveness expressed in median IHS4 improvement (-20 vs. -9, p < 0.001), IHS4-55 (74% vs. 36%, p = 0.002), median draining tunnel reduction (-4 vs. -2, p < 0.001) and pain response (47% vs. 27%, p = 0.02).

CONCLUSION

Adalimumab initiated with clindamycin and rifampicin shows greater clinical effectiveness than adalimumab monotherapy. An important difference in effect was observed in the decrease of draining tunnels, addressing a serious limitation of adalimumab monotherapy.

Complement activation in Hidradenitis suppurativa: Covert low-grade inflammation or innocent bystander?

Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin disease with a complex and multifactorial pathogenesis involving both the innate and adaptive immune system. Despite limited evidence for local complement activation, conflicting results have been published on the role of systemic complement activation in HS. It was hypothesized that complement was consumed in highly inflamed HS skin, trapping complement from the circulation. Therefore, the aim of this study was to evaluate this local complement deposition in HS skin lesions using routine and commonly used complement antibodies.Direct immunofluorescence for C1q, C3c, C4d, C5b-9, and properdin was performed on frozen tissue sections of 19 HS patients and 6 controls. C5a receptor 1 (C5aR1) was visualized using immunohistochemistry.

Overall, we found no significant local complement deposition in HS patients versus controls regarding C1q, C3c, C4d, C5b-9, or properdin on either vessels or immune cells. C5aR1 expression was exclusively found on immune cells, predominantly neutrophilic granulocytes, but not significantly different relatively to the total infiltrate in HS lesions compared with controls. In conclusion, despite not being able to confirm local complement depositions of C1q, C3c, C4d, or properdin using highly sensitive and widely accepted techniques, the increased presence of C5aR1 positive immune cells in HS suggests the importance of complement in the pathogenesis of HS and supports emerging therapies targeting this pathway.

Contribution of Genetics to the Susceptibility to Hidradenitis Suppurativa in a Large, Cross-sectional Dutch Twin Cohort

Importance

Hidradenitis suppurativa is a chronic, inflammatory skin disease in which genetic factors are considered to play a role, with up to 38% of patients reporting a family history. Variations in the γ-secretase genes are found mainly in familial cases with an autosomal dominant pattern of inheritance. These variations are rare in the general population with hidradenitis suppurativa, even in patients who report a family history of the disease.

Objective

To assess the heritability of hidradenitis suppurativa in a nationwide Dutch twin cohort.

Design, Setting, and Participants

In this cross-sectional study on self-reported hidradenitis suppurativa conducted from 2011 to 2016, data were collected from twins participating in the surveys of the nationwide Netherlands Twin Register. All complete twin pairs answering the question on hidradenitis suppurativa in the survey were included: 978 female monozygotic twin pairs and 344 male monozygotic twin pairs and 426 female dizygotic twin pairs, 167 male dizygotic twin pairs, and 428 dizygotic twin pairs of the opposite sex. Statistical analysis was performed from July to November 2019.

Main Outcomes and Measures

The main outcome is the proportion of susceptibility to hidradenitis suppurativa due to additive genetic factors (narrow-sense heritability), dominant genetic factors, common or shared environmental factors, or unshared or unique environmental factors. The main outcome was evaluated prior to data collection.

Results

The prevalence of hidradenitis suppurativa among twin pairs was 1.2% (58 of 4686); the mean (SD) age was 32.7 (15.4) years. The narrow-sense heritability of hidradenitis suppurativa was 77% (95% CI, 54%-90%), with the remainder of the variance due to unshared or unique environmental factors based on an age-adjusted model combining additive genetic factors and unshared or unique environmental factors.

Conclusions and Relevance

The high heritability found in this study suggests a stronger than previously assumed genetic basis of hidradenitis suppurativa. Environmental factors were also shown to contribute to the susceptibility to hidradenitis suppurativa, supporting a multifactorial cause of the disease. Moreover, the results of this study strongly support the need for a global genome-wide association study in the general population of patients with hidradenitis suppurativa.

Contribution of plasma cells and B cells to hidradenitis suppurativa pathogenesis

Hidradenitis suppurativa (HS) is a debilitating chronic inflammatory skin disease characterized by chronic abscess formation and development of multiple draining sinus tracts in the groin, axillae, and perineum. Using proteomic and transcriptomic approaches, we characterized the inflammatory responses in HS in depth, revealing immune responses centered on IFN-γ, IL-36, and TNF, with lesser contribution from IL-17A. We further identified B cells and plasma cells, with associated increases in immunoglobulin production and complement activation, as pivotal players in HS pathogenesis, with Bruton’s tyrosine kinase (BTK) and spleen tyrosine kinase (SYK) pathway activation as a central signal transduction network in HS. These data provide preclinical evidence to accelerate the path toward clinical trials targeting BTK and SYK signaling in moderate-to-severe HS.

B-cells and plasma cells are critical pathogenic cell populations in chronic Hidradenitis Suppurativa and are potential therapeutic targets.

A novel nicastrin mutation in a three-generation Dutch family with hidradenitis suppurativa: a search for functional significance

Background

Mutations in the γ‐secretase enzyme subunits have been described in multiple kindreds with familial hidradenitis suppurativa (HS).

Objective

In this study, we report a novel nicastrin (NCSTN) mutation causing HS in a Dutch family. We sought to explore the immunobiological function of NCSTN mutations using data of the Immunological Genome Project.

Methods

Blood samples of three affected and two unaffected family members were collected. Whole‐genome sequencing was performed using genomic DNA isolated from peripheral blood leucocytes. Sanger sequencing was done to confirm the causative NCSTN variant and the familial segregation. The microarray data set of the Immunological Genome Project was used for thorough dissection of the expression and function of wildtype NCSTN in the immune system.

Results

In a family consisting of 23 members, we found an autosomal dominant inheritance pattern of HS and detected a novel splice site mutation (c.1912_1915delCAGT) in the NCSTN gene resulting in a frameshift and subsequent premature stop. All affected individuals had HS lesions on non‐flexural and atypical locations. Wildtype NCSTN appears to be upregulated in myeloid cells like monocytes and macrophages, and in mesenchymal cells such as fibroblastic reticular cells and fibroblasts. In addition, within the 25 highest co‐expressed genes with NCSTN we identified CAPNS1,ARNT and PPARD.

Conclusion

This study reports the identification a novel NCSTN gene splice site mutation which causes familial HS. The associated immunobiological functions of NCSTN and its co‐expressed genes ARNT and PPARD link genetics to the most common environmental and metabolic HS risk factors which are smoking and obesity.

Quality of life measurement in hidradenitis suppurativa: position statement of the European Academy of Dermatology and Venereology task forces on Quality of Life and Patient-Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa

This paper is organized jointly by the European Academy of Dermatology and Venereology (EADV) Task Force (TF) on Quality of Life (QoL) and Patient-Oriented Outcomes and the EADV TF on acne, rosacea and hidradenitis suppurativa (ARHS). The purpose of this paper was to present current knowledge about QoL assessment in HS, including data on HS-specific health-related (HR) QoL instruments and HRQoL changes in clinical trials, and to make practical recommendations concerning the assessment of QoL in people with HS. HS results in significant quimp that is higher than in most other chronic skin diseases. HS impact in published studies was assessed predominantly (84% of studies) by the Dermatology Life Quality Index (DLQI). There is a lack of high-quality clinical trials in HS patients where HRQoL instruments have been used as outcome measures. One double-blind randomized placebo-controlled trial on infliximab with low number of participants reported significantly better HRQoL improvement in the treatment group than in the placebo group. Well-designed clinical studies in HS patients to compare different treatment methods, including surgical methods and assessing long-term effects, are needed. Because of lack of sufficient validation, the Task Forces are not at present able to recommend existing HS-specific HRQoL instruments for use in clinical studies. The EADV TFs recommend the dermatology-specific DLQI questionnaire for use in HS patients. The EADV TFs encourage the further development, validation and use of other HS-specific, dermatology-specific and generic instruments but such use should be based on the principles presented in the previous publications of the EADV TF on QoL and Patient-Oriented Outcomes.

The anti-inflammatory potency of biologics targeting tumour necrosis factor-α, interleukin (IL)-17A, IL-12/23 and CD20 in hidradenitis suppurativa: an ex vivo study

Background

Biologics targeting inflammatory mediators can achieve clinical improvements in hidradenitis suppurativa (HS). However, their clinical efficacy shows great interpatient variability in daily practice.

Objectives

To investigate the anti‐inflammatory potency of a selection of currently available biologics and prednisolone for the treatment of HS in an ex vivo skin culture system using lesional HS biopsies.

Methods

Lesional skin samples from 10 patients with HS and skin samples from five healthy controls were cultured ex vivo and exposed to prednisolone or biologics targeting tumour necrosis factor (TNF)‐α, interleukin (IL)‐17A, IL‐12/23p40 or CD20 (adalimumab, infliximab, secukinumab, ustekinumab and rituximab, respectively). Real‐time quantitative polymerase chain reaction and cytokine bead arrays were used to measure the inhibitory effect of the biologics on cytokines and antimicrobial peptides (AMPs).

Results

The relative mRNA expression of all tested cytokines and AMPs was significantly downregulated by all anti‐inflammatory agents (P < 0·001). The protein production of the proinflammatory cytokines TNF‐α, interferon γ, IL‐1β, IL‐6 and IL‐17A was significantly inhibited by adalimumab, infliximab, ustekinumab, prednisolone (all P < 0·001) and rituximab (P = 0·0071), but not by secukinumab (P = 0·0663). On both mRNA and protein levels, adalimumab, infliximab and prednisolone reduced the levels of a broader mix of individual cytokines than secukinumab, ustekinumab and rituximab. Moreover, a significant inhibitory effect on mRNA expression levels of inflammatory markers in healthy control skin was observed only for TNF‐α inhibitors (P < 0·001) and prednisolone (P = 0·0015).

Conclusions

This ex vivo study suggests that TNF‐α inhibitors and prednisolone are the most powerful inhibitors of proinflammatory cytokines and AMPs in HS lesional skin, which concurs with our clinical experience in patients with HS.

What's already known about this topic?

A key element of hidradenitis suppurativa (HS) is an aberrant immune response characterized by the overexpression of several proinflammatory cytokines and antimicrobial peptides in lesional skin.

Biologics targeting inflammatory cytokines have the potential to improve HS disease activity.

There is still need for efficacious drugs in the treatment of HS.

What does this study add?

We sought to quantify the anti‐inflammatory effects of currently available biologics in an ex vivo disease model.

Adalimumab, infliximab, secukinumab, ustekinumab and rituximab in addition to prednisolone significantly inhibited a selected panel of proinflammatory cytokines and antimicrobial peptides in ex vivo HS lesional skin.

Adalimumab, infliximab and prednisolone reduced the levels of a broader mix of individual cytokines than secukinumab, ustekinumab and rituximab.

What is the translational message?

The significant inhibition of important proinflammatory cytokines by tumour necrosis factor‐α inhibitors in HS correlates with their clinical efficacy.

Our ex vivo skin culture system represents an adequate model for studies in search of novel candidate drugs for the treatment of HS and to personalize the treatment in specific patients.

Linked Comment: https://doi.org/10.1111/bjd.18173.

https://www.bjdonline.com/article/

Correlation of the refined Hurley classification for hidradenitis suppurativa with patient-reported quality of life and objective disease severity assessment

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, debilitating, heterogeneous disease requiring different treatment approaches. Recently, we refined the classic Hurley classification into a seven-stage classification in order to guide these treatment choices. This new classification subdivides Hurley stage I and II into three substages, namely mild (A), moderate (B) and severe (C) HS disease. Hurley stage III is not subcategorized and is always severe.

OBJECTIVES

To investigate the correlation between the given severity grades of Hurley I and Hurley II in the refined Hurley classification, and the patient-reported quality of life and physician-assessed objective severity score.

MATERIALS AND METHODS

In this cross-sectional study, patients with HS participating in the observational cohorts of two Dutch tertiary referral centres were included before June 2017. The patient-reported Dermatology Life Quality Index (DLQI) and physician-assessed International HS Severity Score System (IHS4) scores were compared between the refined Hurley stages.

RESULTS

In total, 433 patients were analysed. DLQI and IHS4 scores increased within Hurley stage I and II from A through C. There was a significant positive correlation of DLQI and IHS4 with increasing refined Hurley substages [refined Hurley stage I (A, B and C) to DLQI: r_s = 0·259, P < 0·001 and refined Hurley stage II (A, B and C) to DLQI: r_s = 0·185, P = 0·010; refined Hurley stage I (A, B and C) to IHS4: r_s = 0·603, P < 0·001 and refined Hurley stage II (A, B and C) to IHS4: r_s = 0·532, P < 0·001].

CONCLUSIONS

The refined Hurley classification accurately correlates with HS severity assessed by both patients and clinicians. Therefore, the refined Hurley classification is a useful tool for the quick assessment of severity in HS.

Apremilast for moderate hidradenitis suppurativa: no significant change in lesional skin inflammatory biomarkers

Background

Treatment with apremilast has recently demonstrated clinically meaningful improvement in moderate hidradenitis suppurativa (HS).

Objective

To evaluate the change in expression of inflammatory markers in lesional skin of HS patients receiving apremilast 30 mg twice daily (n = 15) for 16 weeks compared with placebo (n = 5).

Methods

At baseline, 5‐mm punch biopsies were obtained from an index lesion (HSL) and non‐lesional (HSN) skin in the same anatomical area. Subsequent HSL samples were taken as close as possible to the previously biopsied site at week 4 and week 16. After sampling, biopsies were split; one half was processed for in vivo mRNA analysis using real‐time quantitative PCR; the other half was cultured for ex vivo protein analysis using a proximity extension assay (Olink). Linear mixed effects models were calculated to compare the levels of inflammatory markers in HSL skin between apremilast and placebo over time.

Results

At baseline, 17 proteins with a fold change >2 in HSL vs. HSN skin were identified in 20 patients. The top five were IL‐17A (5), S100A12, CST5, IL‐12/23p40, CD6 (1) with fold changes ranging from 6.6 to 1638, respectively (FDR <0.044). Linear mixed effects models for 75 assays were calculated. Protein levels of S100A12 decreased during treatment in the apremilast group compared with the placebo group (p = 0.014, FDR = 0.186). None of the 14 genes exhibited significant changes in expression over time. However, an evident downward trend in relative mRNA expression of IL‐17A and IL‐17F was demonstrated in patients receiving apremilast.

Conclusion

We did not detect statistically significant changes in inflammatory markers in HSL skin of HS patients receiving apremilast compared with placebo, despite clinical improvement in the apremilast group. Nonetheless, S100A12 and IL‐17A were significantly elevated in HSL skin and showed a decrease in response to apremilast. The translational model in clinical trials involving HS clearly needs further improvement.

Hidradenitis suppurativa/acne inversa: a practical framework for treatment optimization - systematic review and recommendations from the HS ALLIANCE working group

Hidradenitis suppurativa (HS)/acne inversa is a debilitating chronic disease that remains poorly understood and difficult to manage. Clinical practice is variable, and there is a need for international, evidence‐based and easily applicable consensus on HS management. We report here the findings of a systematic literature review, which were subsequently used as a basis for the development of international consensus recommendations for the management of patients with HS. A systematic literature review was performed for each of nine clinical questions in HS (defined by an expert steering committee), covering comorbidity assessment, therapy (medical, surgical and combinations) and response to treatment. Included articles underwent data extraction and were graded according to the Oxford Centre for Evidence‐based Medicine criteria. Evidence‐based recommendations were then drafted, refined and voted upon, using a modified Delphi process. Overall, 5310 articles were screened, 171 articles were analysed, and 65 were used to derive recommendations. These articles included six randomized controlled trials plus cohort studies and case series. The highest level of evidence concerned dosing recommendations for topical clindamycin in mild disease (with systemic tetracyclines for more frequent/widespread lesions) and biologic therapy (especially adalimumab) as second‐line agents (following conventional therapy failure). Good‐quality evidence was available for the hidradenitis suppurativa clinical response (HiSCR) as a dichotomous outcome measure in inflammatory areas under treatment. Lower‐level evidence supported recommendations for topical triclosan and oral zinc in mild‐to‐moderate HS, systemic clindamycin and rifampicin in moderate HS and intravenous ertapenem in selected patients with more severe disease. Intralesional or systemic steroids may also be considered. Local surgical excision is suggested for mild‐to‐moderate HS, with wide excision for more extensive disease. Despite a paucity of good‐quality data on management decisions in HS, this systematic review has enabled the development of robust and easily applicable clinical recommendations for international physicians based on graded evidence.

Towards global consensus on core outcomes for hidradenitis suppurativa research: an update from the HISTORIC consensus meetings I and II

BACKGROUND

A core outcomes set (COS) is an agreed minimum set of outcomes that should be measured and reported in all clinical trials for a specific condition. Hidradenitis suppurativa (HS) has no agreed-upon COS. A central aspect in the COS development process is to identify a set of candidate outcome domains from a long list of items. Our long list had been developed from patient interviews, a systematic review of the literature and a healthcare professional survey, and initial votes had been cast in two e-Delphi surveys. In this manuscript, we describe two in-person consensus meetings of Delphi participants designed to ensure an inclusive approach to generation of domains from related items.

OBJECTIVES

To consider which items from a long list of candidate items to exclude and which to cluster into outcome domains.

METHODS

The study used an international and multistakeholder approach, involving patients, dermatologists, surgeons, the pharmaceutical industry and medical regulators. The study format was a combination of formal presentations, small group work based on nominal group theory and a subsequent online confirmation survey.

RESULTS

Forty-one individuals from 13 countries and four continents participated. Nine items were excluded and there was consensus to propose seven domains: disease course, physical signs, HS-specific quality of life, satisfaction, symptoms, pain and global assessments.

CONCLUSIONS

The HISTORIC consensus meetings I and II will be followed by further e-Delphi rounds to finalize the core domain set, building on the work of the in-person consensus meetings.

Development and validation of the International Hidradenitis Suppurativa Severity Score System (IHS4), a novel dynamic scoring system to assess HS severity

BACKGROUND

A validated tool for the dynamic severity assessment of hidradenitis suppurativa/acne inversa (HS) is lacking.

OBJECTIVES

To develop and validate a novel dynamic scoring system to assess the severity of HS.

METHODS

A Delphi voting procedure was conducted among the members of the European Hidradenitis Suppurativa Foundation (EHSF) to achieve consensus towards an initial HS Severity Score System (HS4). Strengths and weaknesses of HS4 were examined by a multicentre prospective study. Multivariate logistic regression, discriminant analysis and receiver operating characteristic curves, as well as examination for correlation (Spearman's rho) and agreement (Cohen's kappa) with existing scores, were engaged to recognize the variables for a new International HS4 (IHS4) that was established by a second Delphi round.

RESULTS

Consensus HS4 was based on number of skin lesions, number of skin areas involved and Dermatology Life Quality Index (DLQI), and was evaluated by a sample of 236 patients from 11 centres. Subsequently, a multivariate regression model calculated adjusted odds ratios for several clinical signs. Nodules, abscesses and draining tunnels resulted as the scoring variables. Three candidate scores were presented to the second Delphi round. The resulting IHS4 score is arrived at by the number of nodules (multiplied by 1) plus the number of abscesses (multiplied by 2) plus the number of draining tunnels (multiplied by 4). A total score of 3 or less signifies mild, 4-10 signifies moderate and 11 or higher signifies severe disease. Cohen's kappa was fair (κ = 0·32) compared with Hurley classification, and moderate (κ = 0·49) compared with Expert Opinion. Correlation was good (ρ > 0·6) with Hurley classification, Expert Opinion, Physician's Global Assessment and Modified Sartorius score, and moderate for DLQI (ρ = 0·36).

CONCLUSIONS

The novel IHS4 is a validated tool to dynamically assess HS severity and can be used both in real-life and the clinical trials setting.

Sexual health and quality of life are impaired in hidradenitis suppurativa: a multicentre cross-sectional study

BACKGROUND

Hidradenitis suppurativa (HS) has a major impact on patients' quality of life (QoL). Although it has commonly been assumed that HS impairs sexual health, only a single case-control study has been performed on sexual functioning in a small group of patients with HS.

OBJECTIVES

To investigate the QoL with a particular focus on sexual health in a substantial population of patients with HS.

METHODS

In total 916 patients with HS received an invitation to participate in this multicentre cross-sectional survey.

RESULTS

Three hundred patients completed the questionnaires. This study showed a diminished QoL and sexual health in patients with HS (Female Sexual Function Index: 21·6 ± 9·6, International Index of Erectile Function: 49·7 ± 20·7, Arizona Sexual Experience Scale: 16·7 ± 5·3, Dermatology Life Quality Index: 12·5 ± 7·5). Sexual health was associated with QoL in women but not in men. Female sex and late onset of HS were associated with poor sexual function. Impairment of QoL was associated with anogenital involvement, early onset of HS, disease severity and disease activity.

CONCLUSIONS

HS is associated with impaired sexual health and QoL. Physicians should not hesitate to ask patients with HS about their sexual function and, when needed, offer them psychological support.

European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa

Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating skin disease of the hair follicle that usually presents after puberty with painful, deep-seated, inflamed lesions in the apocrine gland-bearing areas of the body, most commonly the axillae, inguinal and anogenital regions. A mean disease incidence of 6.0 per 100,000 person-years and an average prevalence of 1% has been reported in Europe. HS has the highest impact on patients' quality of life among all assessed dermatological diseases. HS is associated with a variety of concomitant and secondary diseases, such as obesity, metabolic syndrome, inflammatory bowel disease, e.g. Crohn's disease, spondyloarthropathy, follicular occlusion syndrome and other hyperergic diseases. The central pathogenic event in HS is believed to be the occlusion of the upper part of the hair follicle leading to a perifollicular lympho-histiocytic inflammation. A highly significant association between the prevalence of HS and current smoking (Odds ratio 12.55) and overweight (Odds ratio 1.1 for each body mass index unit) has been documented. The European S1 HS guideline suggests that the disease should be treated based on its individual subjective impact and objective severity. Locally recurring lesions can be treated by classical surgery or LASER techniques, whereas medical treatment either as monotherapy or in combination with radical surgery is more appropriate for widely spread lesions. Medical therapy may include antibiotics (clindamycin plus rifampicine, tetracyclines), acitretin and biologics (adalimumab, infliximab). A Hurley severity grade-relevant treatment of HS is recommended by the expert group following a treatment algorithm. Adjuvant measurements, such as pain management, treatment of superinfections, weight loss and tobacco abstinence have to be considered.

Failure of anti-interleukin-1 therapy in severe hidradenitis suppurativa: a case report

Hidradenitis suppurativa (HS) is an inflammatory, debilitating skin disease of follicular origin, characterized by painful deep-seated, inflamed lesions in mainly the inverse areas of the body. HS is notoriously difficult to treat and especially severe disease is often resistant to therapy. New therapeutic options are therefore highly needed. Elevated levels of IL-1 have been demonstrated in HS lesions. Here we report for the first time on the sequential treatment with anakinra (an IL-1 receptor antagonist) and golimumab (a TNF-α-neutralizing antibody) of a patient with severe HS and with comorbid psoriatic arthritis. Although adalimumab and golimumab were efficacious in improving arthritis complaints, both failed in improving the severe HS of our patient. Eventually the patient underwent radical excision of the inflammatory lesions and fistulas.

Can animal skin diseases or current transgenic mice serve as a model for hidradenitis suppurativa?

The pathogenesis of hidradenitis suppurativa (HS) is still enigmatic, and a valid animal model for HS is currently not available. The recent discovery of γ-secretase mutations in a subpopulation of patients with HS suggested γ-secretase transgenic mice as a model for HS pathogenesis. However, the discrepancies between human HS and these mice are daunting. We critically review cases of animal HS and transgenic γ-secretase mouse models for HS and discuss the criteria which should be met for a representative pathogenic model.

Adalimumab (antitumour necrosis factor-α) treatment of hidradenitis suppurativa ameliorates skin inflammation: an in situ and ex vivo study

BACKGROUND

Hidradenitis suppurativa (HS) is a difficult-to-manage disease. Randomized controlled trials with antitumour necrosis factor (TNF)-α biologics have been conducted and in most studies disease activity was reduced. However, the mechanism of action in HS skin is so far unknown.

OBJECTIVES

To assess whether anti-TNF-α treatment affects in situ cytokine production and frequency of inflammatory cell populations in HS lesional skin.

METHODS

Nine patients with HS, participating in a larger placebo-controlled, double-blind phase IIb clinical trial on the efficacy and safety of adalimumab in patients with moderate to severe HS (M10-467), were randomized and treated for 16weeks. In a mechanism-of-action substudy, biopsies were obtained at fixed time points pre- and post-treatment. One part of the biopsy was cultured for 24h for cytokine release in the culture medium, while another part was used for in situ analysis.

RESULTS

Secretion of cytokines, including interleukin (IL)-1β, CXCL9 [monokine induced by interferon-γ (MIG)], IL-10, IL-11, B-lymphocyte chemoattractant (BLC) and IL-17A, was significantly elevated in HS. Adalimumab treatment was associated with decreased production of cytokines in HS skin, especially IL-1β, CXCL9 (MIG) and BLC. Treatment significantly reduced the number of CD11c+,CD14+ and CD68+ cells in HS lesional skin. The numbers of CD3+ and CD4+ T cells, and CD20+ and CD138+ B cells were also reduced by adalimumab treatment.

CONCLUSIONS

Adalimumab treatment inhibits important cytokines and inflammatory cell numbers in lesional HS skin, especially levels of IL-1β and numbers of inflammatory CD11c+ dendritic cells.

Depression in patients with hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic recurrent inflammatory skin disease with abscess formation and scarring predominantly in the inverse areas. The disease is often difficult to treat and patients experience a decreased quality of life (QoL). It is hypothesized that depression is more common in HS patients than among other dermatological patients.

OBJECTIVES

To evaluate the prevalence of depression in patients with HS.

METHODS

In total 211 HS patients were included in the study and 233 were dermatological control patients. Their QoL and depression scores were assessed using the Dermatology Life Quality Index (DLQI) and the Major Depression Inventory (MDI) questionnaires. HS severity was recorded with a questionnaire and Hurley stages were extracted from the case records.

RESULTS

The DLQI was significantly higher for HS patients than for the control patients, 8.4 ± 7.5 vs. 4.3 ± 5.6 (P < 0.0001) and correlated with Hurley stage severity scores. Mean MDI scores were significantly higher for HS patients, 11.0 vs. 7.2 (P < 0.0001). However, clinically defined depression rates according to the International Classification of Diseases, 10th edition (ICD-10) criteria were not significantly higher in HS patients compared to controls (9% vs. 6%).

CONCLUSIONS

HS is a chronic skin disease with major impact on QoL even when compared to other dermatological diseases. MDI scores in HS patients correlate with disease severity. This correlation could indicate that the MDI represents a valid measure of disease related morbidity that may serve as an outcome measure in future studies and a relevant point of intervention for individual patients.

Alterations in leucocyte subsets and histomorphology in normal-appearing perilesional skin and early and chronic hidradenitis suppurativa lesions

BACKGROUND

Current insight into the histopathological course of events during disease progression in hidradenitis suppurativa (HS) is fragmentary.

OBJECTIVES

To identify histological alterations and leucocyte subsets in normal-appearing perilesional skin, and early and chronic HS lesions.

METHODS

In this observational study we examined eight perilesional skin samples, and six early and 10 chronic prototypic HS lesions, as well as skin samples from four healthy donors using in situ immunostaining.

RESULTS

Perilesional skin showed mild psoriasiform hyperplasia and follicular plugging as well as a low-grade influx of tryptase-positive mast cells, CD3+ T cells, CD138+ plasma cells and factor XIIIa+ dendritic cells. In early HS lesions, neutrophilic abscess formation and influx of mainly macrophages, monocytes and dendritic cells predominated. In chronic disease, the infiltrate expanded with markedly increased frequencies of CD20+ and CD79a+ B cells and CD138+ plasma cells. As in early lesions, free keratin fibres were detected in the dermis and within giant cells. Single detached keratinocytes and strands of follicular epithelium were observed in the dermis, the latter frequently expressing Ki67, indicative of active proliferation.

CONCLUSIONS

Psoriasiform hyperplasia, follicular plugging and low-grade leucocytic infiltration are already present in normal-appearing perilesional skin. Keratin fibres in the dermis are associated with clinical disease. Early lesions are characterized by neutrophilic abscess formation and influx of mainly histiocytes, and chronic lesions mainly by expansion of B cells and plasma cells in 'pseudo' follicles. Proliferating strands of follicular epithelium may initiate fistula formation. Mast cells are increased in all stages of HS including perilesional skin.

The anti-inflammatory drug colchicine lacks efficacy in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease. Since current treatments are unsatisfactory for many patients, there is a high need for effective drugs for this debilitating disease. Recent pathogenic insights suggest inflammasome activation and IL-1β production are important in HS. Colchicine is efficacious in the IL-1β- and inflammasome-mediated diseases gout, familial Mediterranean fever and Behçet's disease, and therefore a potentially effective drug in HS.

OBJECTIVE

To investigate the efficacy of colchicine in HS.

METHODS

In an open prospective pilot study, 8 HS patients were treated with the accepted gout maintenance regimen of 0.5 mg colchicine b.i.d. orally up to 4 months. Efficacy was assessed by a physician global assessment.

RESULTS

Colchicine treatment did not result in a clinically relevant improvement of disease severity. Three patients experienced nausea and diarrhea as known side effects.

CONCLUSION

Colchicine in the used dose regimen does not ameliorate HS severity.

Pathogenesis and pharmacotherapy of Hidradenitis suppurativa

The focus of this review is to discuss the pathogenesis and the pharmacotherapy of Hidradenitis suppurativa (HS). HS is a distressing chronic skin disorder characterized by abscesses, boils, fistulas and scarring, generally affecting the groins, anogenital area and axillae. It is a common disease with an estimated prevalence of 1%. The etiology is unknown. HS was thought to be a disease of the apocrine sweat glands, but histological findings indicate that HS is a disease arising from the hair follicles. Several pathogenic factors seem important including genetic predisposition, smoking, obesity and an aberrant immune response to commensal flora. The management of HS is tremendously challenging because effective therapies are lacking. Nevertheless, HS has been treated with topical and systemic antibiotics, retinoids and immunosuppressive drugs such as anti-TNF-α biologics with partial success. In this review we will also discuss a potential new therapy for HS with the anti-psoriases agent acitretin.

Elevated levels of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-10 in hidradenitis suppurativa skin: a rationale for targeting TNF-α and IL-1β

BACKGROUND

The pathogenesis of hidradenitis suppurativa (HS) is largely unknown and the disease is difficult to treat. Patients are in high need of an effective treatment. Although it is not known whether the levels of tumour necrosis factor (TNF)-α are aberrant in HS skin, anti-TNF-α biologics are used, with variable clinical efficacy.

OBJECTIVES

To determine the cytokine profile in lesional and perilesional HS skin.

METHODS

We cultured 20 lesional and 10 normal-appearing perilesional HS skin samples, seven psoriasis and six healthy control skin samples in a transwell culture system. Two distinct cytokine bead arrays were used to measure the spectrum of inflammatory cytokines in the culture supernatant. Results from HS skin samples were compared with those of healthy and psoriasis skin.

RESULTS

The proinflammatory cytokines interleukin (IL)-1β and TNF-α as well as the anti-inflammatory cytokine IL-10 were significantly elevated in HS skin. Elevated levels of these cytokines were also found in perilesional HS skin. Fold increases relative to control skin of IL-1β, TNF-α and IL-10 in HS were 31, 5 and 34, compared with psoriasis: 4, 1 and 2, respectively. Levels of all three cytokines showed a trend towards a positive correlation with disease severity. IL-2, IL-4, IL-5 and interferon-γ were hardly detectable in HS or healthy control skin.

CONCLUSIONS

This study shows for the first time that IL-1β, TNF-α and IL-10 levels are elevated in HS skin. These data provide a rationale for therapies with biologics targeting cytokines such as TNF-α and IL-1.

Hidradenitis suppurativa and inflammatory bowel disease: are they associated? Results of a pilot study

Background The co-occurrence of hidradenitis suppurativa (HS) and Crohn disease (CD) published in a few case reports resulted in the wide acceptance of an association between these two diseases. However, the combined prevalence of these diseases is currently unknown; furthermore, it is unknown whether this co-occurrence also applies for ulcerative colitis (UC). Objectives To estimate the prevalence of HS in patients with inflammatory bowel disease (IBD) living in the Southwest of the Netherlands. Methods During an IBD patient information meeting, randomly, 158 patients with IBD were interviewed about recurrent painful boils in the axillae and/or groin and were shown illustrative clinical pictures of the appearance of HS. Results Of the 158 patients interviewed, 102 (65%) had CD and 56 (35%) had UC. Twenty-five people (16%) responded that they had had or still experienced painful boils in the axillae and/or groin, of whom 17 were patients with CD (17%) and eight had UC (14%). Conclusions This pilot study shows for the first time that HS occurs in patients with CD or UC. More prospective studies are warranted to establish the association between HS and IBD and its underlying pathogenesis.

[Diagnostic image (319). A man with multiple yellow nodules]

A 57-year-old man with liver function disturbances, probably due to alcohol abuse, presented with multiple yellow skin nodules: eruptive xanthomas. He used to consume pork excessively and had strongly elevated plasma triglyceride and cholesterol levels.