B-cell and complement signature in severe hidradenitis suppurativa that does not respond to adalimumab.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder with significant morbidity. The pathogenesis remains incompletely understood although immune dysregulation plays an important role. It is challenging to treat and approximately 50% of patients respond clinically to adalimumab, the only licensed treatment. OBJECTIVES: To examine differences between lesional and nonlesional HS skin at baseline using bulk RNA sequencing, and to compare the transcriptome in the skin before and after 12 weeks of treatment with adalimumab. To examine transcriptomic differences between adalimumab responders and nonresponders using Hidradenitis Suppurativa Clinical Response and the International Hidradenitis Suppurativa Severity Score System (IHS4); and to compare transcriptomic differences based on disease severity (Hurley stage and IHS4). METHODS: We completed bulk RNA sequencing on lesional and nonlesional skin samples of patients before and after 12 weeks of treatment with adalimumab. RESULTS: Baseline differentially expressed genes and pathways between lesional and nonlesional skin highlighted chemokines and antimicrobial peptides produced by keratinocytes; B-cell function; T-cell-receptor, interleukin-17 and nuclear factor-κB signalling; and T-helper-cell differentiation. Transcriptomic differences were identified in lesional skin at baseline, between subsequent responders and nonresponders. Patients with severe HS who did not respond to adalimumab had enriched complement and B-cell activation pathways at baseline. In addition, logistic regression identified CCL28 in baseline lesional HS skin as a potential biomarker of treatment response. CONCLUSIONS: This highlights the potential for targeting B-cell and complement pathways in HS treatment and the potential of stratifying patients at baseline to the most suitable treatment based on the skin transcriptome. CCL28 has not previously been identified in HS skin and has potential clinical relevance due to its antimicrobial function and homing of B and T cells at epithelial surfaces. Our results provide data to inform future translational and clinical studies on therapeutics in HS.

Metformin has anti-inflammatory effects and induces immunometabolic reprogramming via multiple mechanisms in hidradenitis suppurativa.

BACKGROUND: Targeting immunometabolism has shown promise in treating autoimmune and inflammatory conditions. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease involving painful lesions in apocrine gland-bearing skin. Therapeutic options for HS are limited and often ineffective; thus, there is a pressing need for improved treatments. To date, metabolic dysregulation has not been investigated in HS. As HS is highly inflammatory, we hypothesized that energy metabolism is dysregulated in these patients. Metformin, an antidiabetic drug, which is known to impact on cellular metabolic and signalling pathways, has been shown to have anti-inflammatory effects in cancer and arthritis. While metformin is not licensed for use in HS, patients with HS taking metformin show improved clinical symptoms. OBJECTIVE: To assess the effect and mechanism of action of metformin in HS. METHODS: To assess the effect of metformin in vivo, we compared the immune and metabolic profiles of peripheral blood mononuclear cells (PBMCs) of patients with HS taking metformin vs. those not taking metformin. To examine the effect of metformin treatment ex vivo, we employed a skin explant model on skin biopsies from patients with HS not taking metformin, which we cultured with metformin overnight. We used enzyme-linked immunosorbent assays, multiplex cytokine assays and quantitative real-time polymerase chain reaction (RT-PCR) to measure inflammatory markers, and Seahorse flux technology and quantitative RT-PCR to assess glucose metabolism. RESULTS: We showed that metabolic pathways are dysregulated in the PBMCs of patients with HS vs. healthy individuals. In metformin-treated patients, these metabolic pathways were restored and their PBMCs had reduced inflammatory markers following long-term metformin treatment. In the skin explant model, we found that overnight culture with metformin reduced inflammatory cytokines and chemokines and glycolytic genes in lesions and tracts of patients with HS. Using in vitro assays, we found that metformin may induce these changes via the NLR family pyrin domain containing 3 (NLRP3) inflammasome and the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway, which is linked to glycolysis and protein synthesis. CONCLUSIONS: Our study provides insight into the mechanisms of action of metformin in HS. The anti-inflammatory effects of metformin support its use as a therapeutic agent in HS, while its effects on immunometabolism suggest that targeting metabolism is a promising therapeutic option in inflammatory diseases, including HS.

Targeting the NLRP3 inflammasome reduces inflammation in hidradenitis suppurativa skin.

BACKGROUND: Treatment for the debilitating disease hidradenitis suppurativa (HS) is inadequate in many patients. Despite an incidence of approximately 1%, HS is often under-recognized and underdiagnosed, and is associated with a high morbidity and poor quality of life. OBJECTIVES: To gain a better understanding of the pathogenesis of HS, in order to design new therapeutic strategies. METHODS: We employed single-cell RNA sequencing to analyse gene expression in immune cells isolated from involved HS skin vs. healthy skin. Flow cytometry was used to quantify the absolute numbers of the main immune populations. The secretion of inflammatory mediators from skin explant cultures was measured using multiplex and enzyme-linked immunosorbent assays. RESULTS: Single-cell RNA sequencing analysis identified a significant enrichment in the frequency of plasma cells, T helper (Th) 17 cells and dendritic cell subsets in HS skin, and the immune transcriptome was distinct and more heterogeneous than healthy skin. Flow cytometry revealed significantly increased numbers of T cells, B cells, neutrophils, dermal macrophages and dendritic cells in HS skin. Genes and pathways associated with Th17 cells, interleukin (IL)-17, IL-1ß and the NLRP3 inflammasome were enhanced in HS skin, particularly in samples with a high inflammatory load. Inflammasome constituent genes principally mapped to Langerhans cells and a subpopulation of dendritic cells. The secretome of HS skin explants contained significantly increased concentrations of inflammatory mediators, including IL-1ß and IL-17A, and culture with an NLRP3 inflammasome inhibitor significantly reduced the secretion of these, as well as other, key mediators of inflammation. CONCLUSIONS: These data provide a rationale for targeting the NLRP3 inflammasome in HS using small-molecule inhibitors that are currently being tested for other indications.

Metformin Treatment of Hidradenitis Suppurativa: Effect on Metabolic Parameters, Inflammation, Cardiovascular Risk Biomarkers, and Immune Mediators.

Hidradenitis suppurativa (HS) is a common cutaneous and systemic inflammatory disease with a significant impact on mental health and quality of life. It is associated with obesity, insulin resistance, metabolic syndrome, cardiovascular (CV) disease, and increased all-cause mortality. Metformin is used frequently in HS treatment and is effective for some patients. The mechanism of action of metformin in HS is unknown. A case-control study of 40 patients with HS (20 on metformin and 20 controls) was conducted to assess differences in metabolic markers, inflammation (C-reactive protein [CRP], serum adipokines, and CV risk biomarkers), and serum immune mediators. Body mass index (BMI), insulin resistance (77%), and metabolic syndrome (44%) were high overall, but not significantly different between the groups. This highlights the need for co-morbidity screening and management. A significant reduction in fasting insulin and a trend towards a reduction in insulin resistance were identified in the metformin group compared with pre-treatment levels. CV risk biomarkers were significantly favourable in the metformin group (lymphocytes, monocyte-lymphocyte ratio, neutrophil-lymphocyte ratio, and platelet-lymphocyte ratio). CRP was lower in the metformin group but was not statistically significant. Adipokines were dysregulated overall but were not different between the two groups. Serum IFN-γ, IL-8, TNF-α, and CXCL1 trended lower in the metformin group but did not reach significance. These results suggest that metformin improves CV risk biomarkers and insulin resistance in patients with HS. When the results of this study are considered alongside other studies in HS and related conditions, it is likely that metformin also has beneficial effects on metabolic markers and systemic inflammation in HS (CRP, serum adipokines, and immune mediators), warranting further research.

Sitagliptin and Narrow-Band Ultraviolet-B for Moderate Psoriasis (DINUP): A Randomised Controlled Clinical Trial.

BACKGROUND: Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor licensed for the treatment of type 2 diabetes mellitus (T2DM), has been reported to improve psoriasis. OBJECTIVE: We compared the effects of sitagliptin treatment, a DPP-4 inhibitor, in combination with narrow-band ultraviolet-B (NB-UVB) phototherapy compared to NB-UVB alone on psoriasis severity, quality of life, cardiovascular disease risk factors and immune parameters in people with moderate psoriasis without T2DM. METHODS: In this 39-week, single-centre, randomised controlled trial, people were allocated randomly to receive sitagliptin for 24 weeks with NB-UVB or NB-UVB alone. The primary endpoint was the change in Psoriasis Area and Severity Index (PASI) from baseline to 24 weeks. We estimated that 120 participants would be needed to have 80% power to find a significant difference between the groups. RESULTS: A total of 118 patients were randomised. The median (IQR) baseline PASI was 8.8 (7.5-11.6). At 24 weeks, the mean difference from baseline in PASI (-1.0 [95% CI -2.0 to 0.0]) was significantly larger in the sitagliptin/NB-UVB arm than in the NB-UVB-alone arm (p = 0.044). There were significant differences in the change in Hospital Anxiety and Depression Scale (-2.5 [95% CI -4.0 to -1.0]; p = 0.002) and EuroQol 5-item questionnaire (0.1 [95% CI 0.0-0.1]; p = 0.036) values from baseline to 24 weeks between the sitagliptin/NB-UVB and the NB-UVB-alone arm. There were no treatment-related serious adverse events. CONCLUSION: Sitagliptin therapy combined with NB-UVB phototherapy significantly improved psoriasis severity, albeit modestly, compared to NB-UVB phototherapy alone in patients with moderate psoriasis without T2DM.

Innate lymphoid cell (ILC) subsets are enriched in the skin of patients with hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic relapsing inflammatory skin disease manifested as painful inflamed lesions including deep-seated nodules, abscesses and sinus tracts. The exact aetiology of HS is unclear. Recent evidence suggests that immune dysregulation plays a crucial role in pathogenesis and disease progression. Innate lymphoid cells (ILC) are a recently identified immune cell subset involved in mediating immunity, however their role in HS has not yet been investigated. Three distinct subsets of ILC- ILC1, ILC2 and ILC3 have been described, and these are involved in skin tissue homeostasis and pathologic inflammation associated with autoimmunity and allergic diseases. In this study, we analysed by multiparameter flow cytometry the frequencies of ILC subsets in skin and peripheral blood mononuclear cells (PBMC) of HS patients and compared these to healthy control subjects and psoriasis patients. The absolute numbers of total ILC and subsets thereof were significantly reduced in the blood of HS patients relative to healthy controls. However, when patients were stratified according to treatment, this reduction was no longer observed in patients undergoing anti-TNF treatment. In HS lesional skin the absolute numbers of ILC were significantly increased relative to control skin. Furthermore, the frequencies of total ILC as well as ILC2 and ILC3 were significantly higher in non-lesional than lesional HS skin. This study analysed for the first time the presence of ILC subsets in the blood and skin of HS patients. Our findings suggest that ILC may participate in HS pathogenesis.

High Levels of Psychological Distress, Sleep Disturbance, and Alcohol Use Disorder in Adults With Atopic Dermatitis.

BACKGROUND: The burden of illness associated with atopic dermatitis (AD) is significant and multidimensional, especially in those with moderate to severe disease. OBJECTIVE: Our objective was to evaluate the disease burden of patients with AD in relation to psychological distress, sleep disturbance, and alcohol misuse. METHODS: Patients with AD, attending 2 tertiary referral centers in Dublin, Ireland, were recruited. A series of validated questionnaires were used including the Patient-Oriented Eczema Measure, Dermatology Life Quality Index (DLQI), Center for Epidemiologic Studies-Depression Scale, Quality of Life in Atopic Dermatitis Questionnaire, Alcohol Use Disorders Identification Test, and Pittsburgh Sleep Quality Index. The Eczema Area and Severity Index was calculated contemporaneously with the questionnaire completion. RESULTS: One hundred patients completed the questionnaire, of whom 52% were female. Sixty-three percent of patients experienced impaired quality of life as measured by the DLQI. Higher DLQI scores correlated with decreasing age (r = 0.3277, P < 0.0009). Thirty percent were found to be at risk of clinical depression, and higher Center for Epidemiologic Studies-Depression Scale scores correlated with a younger age and eczema severity. Sleep disturbance was greater in those at risk of depression (mean = 10.40 vs 5.79, P < 0.0001). Patients with moderate to severe AD were more likely to score higher on the Alcohol Use Disorders Identification Test, and 25% met the criteria for alcohol use disorder. In relation to sleep, 73% of patients scored higher than 5 on the Pittsburgh Sleep Quality Index, which signifies poor sleep quality. CONCLUSIONS: Patients with AD endure a significant burden on health with regard to mental well-being, alcohol use, and sleep quality. Clinicians should consider screening patients for these comorbidities.

Metformin use in hidradenitis suppurativa.

Background: Hidradenitis suppurativa (HS) is a chronic debilitating inflammatory disease, associated with metabolic syndrome, obesity and insulin resistance. Metformin, an oral hypoglycaemic agent, may play an important role in delaying or preventing the onset of diabetes and metabolic syndrome. Metformin has been reported as having efficacy in HS. It may have a role in the treatment of HS and its associated co-morbidities.Objective: To evaluate metformin use, response and tolerability in a HS population.Methods: A retrospective chart review of patients attending a specialist Dermatology HS clinic over 12 months. All patients treated with metformin were included.Results: Fifty-three HS patients received metformin; 85% female; mean age was 37 years and mean weight was 102 kg. The mean duration of metformin was 11.3 months and mean dose was 1.5 g/days. The 6- and 12-month drug survival were 61% and 39%, respectively. Metformin was well tolerated. Gastrointestinal side effects were experienced by 11%. Subjective clinical response was seen in 68% (n = 36) with 19% (7/36) of these having quiescent disease with metformin monotherapy. 25% had no improvement. Insulin resistance was seen in 75%. Its presence did not predict clinical response to metformin.Conclusion: Metformin is an effective, well tolerated and inexpensive treatment that represents a viable treatment option for HS.Key message: Metformin is an effective; well tolerated and inexpensive treatment in the management of HS.

Association of Biologic Treatment in Hidradenitis Suppurativa With Reduced Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio.

This cohort study assesses whether an association exists between biologic treatment for hidradenitis suppurativa and neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and monocyte-lymphocyte ratio.

Naturally derived Heme-Oxygenase 1 inducers attenuate inflammatory responses in human dendritic cells and T cells: relevance for psoriasis treatment.

Psoriasis is a chronic autoimmune disease mediated by dysregulated immune responses in dendritic cells (DC) and T cells. The stress-response enzyme heme oxygenase-1 (HO-1) has been described as protective in animal models of psoriasis, however, implementation of HO-1-based therapies is hindered by the lack of clinically-suitable HO-1 inducers. The plant-derived polyphenols, carnosol and curcumin, have been identified as candidate HO-1 inducers however there has been little investigation into their effects on human immune cells. We demonstrate that treatment of human DC with these polyphenols limits DC maturation, reduces pro-inflammatory cytokine production, and prevents induction of allospecific T cell responses, in a manner partially dependent on carbon monoxide (CO). We also characterised their effects in ex-vivo psoriasis PBMC and report that curcumin, but not carnosol, strongly reduces T cell proliferation and cytokine poly-functionality, with reduced expression of psoriatic cytokines IFNγ, IL-17, GM-CSF and IL-22. This study therefore supports reports highlighting the therapeutic potential of curcumin in psoriasis by providing insight into its immunological effects on healthy human DC and psoriasis PBMC. We also demonstrate, for the first time, the anti-inflammatory effects of carnosol in human immune cells.

Methadone-maintained patients in primary care have higher rates of chronic disease and multimorbidity, and use health services more intensively than matched controls.

BACKGROUND: Methadone maintenance treatment in primary care is cost-effective and improves outcomes for opiate-dependent patients. A more developed understanding of the evolving needs of this important cohort will facilitate further improvements in their integrated care within the community. OBJECTIVES: The aim of this study was to compare the burden of chronic disease, multi-morbidity and intensity of health-service use between methadone-maintained patients (MMPs) and matched controls in primary care. METHODS: This is a retrospective matched case-control design. Data on chronic disease and health service use was collected in 13 computerized GP surgeries on 414 patients (207 MMPs and 207 controls). Twelve months of records were examined. MMPs were compared with controls matched by gender, age, socio-economic status (SES) and GP surgery. RESULTS: MMPs suffered more chronic disease (OR = 9.1, 95% CI: 5.4-15.1, P < 0.001) and multi-morbidity (OR = 6.6, 95% CI: 4.3-10.2, P < 0.001). They had higher rates of respiratory, psychiatric and infectious disease. MMPs of lower SES had more chronic disease than their peers (OR = 7.2, 95% CI: 2.4-22.0, P < 0.001). MMPs attended the doctor more often with medical problems (OR = 15.4, 95% CI: 8.2-28.7, P < 0.001), with a frequent requirement to have medical issues addressed during methadone-management visits. Their care generated more telephone calls (OR = 4.4, 95% CI: 2.8-6.8, P < 0.001), investigations (OR = 1.8, 95% CI: 1.2-2.7, P = 0.003), referrals (2.6, 95% CI: 1.7-4.0, P < 0.001), emergency department visits (2.1, 95% CI: 1.3-3.6, P = 0.004), outpatient attendances (2.3, 95% CI: 1.51-1.43, P < 0.001) and hospital admissions (3.6, 95% CI: 1.6-8.1, P = 0.001). CONCLUSION: Correcting for routine methadone care and drug-related illnesses, MMPs had a higher burden of chronic disease and used both primary and secondary health services more intensively than matched controls.