Category Archives: Experimental Dermatology

Vulvar‐vaginal‐gingival‐otic syndrome

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Abstract

In order to retrospectively analyse the multi-site involvement pattern of erosive lichen planus patients, we retrospectively reported the clinical and medical data of three patients with erosive lichen planus which involving their vulva, vagina, gingiva, and ear canal. We confirmed the existence of otic lichen planus, and found that it is more common in patients with vulvovaginal-gingival syndrome of erosive lichen planus. Therefore, we propose ‘vulvovaginal-gingival-otic syndrome’ to further describe this rare compound pattern of lichen planus.

Requisite instruments for the establishment of three‐dimensional epidermal human skin equivalents—A methods review

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Abstract

Human skin equivalents (HSEs) are three-dimensional skin organ culture models raised in vitro. This review gives an overview of common techniques for setting up HSEs. The HSE consists of an artificial dermis and epidermis. 3T3-J2 murine fibroblasts, purchased human fibroblasts or freshly isolated and cultured fibroblasts, together with other components, for example, collagen type I, are used to build the scaffold. Freshly isolated and cultured keratinocytes are seeded on top. It is possible to add other cell types, for example, melanocytes, to the HSE—depending on the research question. After several days and further steps, the 3D skin can be harvested. Additionally, we show possible markers and techniques for evaluation of artificial skin. Furthermore, we provide a comparison of HSEs to human skin organ culture, a model which employs human donor skin. We outline advantages and limitations of both models and discuss future perspectives in using HSEs.

Neutrophil extracellular traps formation in the lesional skin of various types of pyoderma gangrenosum

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Abstract

Pyoderma gangrenosum (PG) is a chronic neutrophilic disorder characterized by recurrent painful ulcers. Aseptic inflammation by neutrophils plays an essential role, and neutrophil extracellular traps (NETs) formation can contribute to the pathogenesis of PG. Seventy-five patients were diagnosed as having PG in our department, among which 58 ulcerative, 4 bullous, 3 pustular and 10 vegetative type. We examined the 20 skin biopsy specimens (11 ulcerative, 3 bullous, 2 pustular and 4 vegetative type), and local NETs formation in various types of PG was compared among each type. The biopsied specimens were double labelled for myeloperoxidase, citrullinated histone H3. Immunofluorescent images indicated that the histopathologic location and depth of NETs formation in PG varied by the clinical subtypes. In ulcerative PG, NETs formation was observed in the upper to deep dermis. In bullous PG, NETs formation was mainly observed in the epidermis. Pustular type showed NETs formation in the epidermis near the pustules, and in vegetative type, showed NETs formation mainly in the upper dermis. These results indicate that NETting neutrophils play an important role in the pathogenesis of various forms of PG, although the location and depth of NETs formation in the skin lesion of PG differ depending on each type. Further studies are necessary to examine what factors identify different clinical features of PG.

Clinical and patient‐reported outcomes from the first 4 years of a Psoriasis Biologics Registry in Singapore

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Abstract

Interim analysis of the National Skin Centre Singapore Psoriasis Biologics Registry (SINGPSOR) from August 2017 to May 2021, in which 58 patients were analysed, showing that those receiving biologic treatment had significantly more severe psoriasis based on PASI (Psoriasis Area and Severity Index), BSA (body surface area) and PGA (Physician Global Assessment) measures at baseline, demonstrated a statistically non-significant trend towards greater improvement with treatment, and had a lower percentage of adverse events compared to those receiving conventional systemic therapy. Future analyses of SINGPSOR, with larger sample size and longer follow-up, will be invaluable to further characterize these patients and their treatment outcomes.

Increased formation of neutrophil extracellular traps induced by autophagy and identification of autophagy‐related biomarkers in systemic lupus erythematosus

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Abstract

Abnormal death of neutrophils and the subsequent ineffective clearance of cell fragments result in production of autoantigens that can lead to systemic lupus erythematosus (SLE). Excessive formation of neutrophil extracellular traps (NETs) can trigger the synthesis of pro-inflammatory cytokines such as type I interferons, leading to tissue damage and immune dysfunction in SLE patients. In this study, we found that a decrease in neutrophil counts in the peripheral blood was correlated with clinical parameters in SLE patients. Patients with low neutrophil counts had high renal activity index and chronicity index scores. NET formation and neutrophil autophagy in SLE patients were increased. The autophagy inhibitor hydroxychloroquine was shown to restrict NET formation. Using comprehensive bioinformatics analysis, we found that the expression of the autophagy-related gene, hypoxia-inducible factor 1A (HIF1A), was enhanced in peripheral neutrophils and in the renal glomeruli in SLE patients. Targeting HIF1A could be a potential therapeutic approach for SLE.

Mast cells are upregulated in hidradenitis suppurativa tissue, associated with epithelialized tunnels and normalized by spleen tyrosine kinase antagonism

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Abstract

Mast cells have traditionally been associated with allergic inflammatory responses; however, they play important roles in cutaneous innate immunity and wound healing. The Hidradenitis Suppurativa tissue transcriptome is associated with alterations in innate immunity and wound healing-associated pathways; however, the role of mast cells in the disease is unexplored. We demonstrate that mast cell-associated gene expression (using whole tissue RNAseq) is upregulated, and in-silico cellular deconvolution identifies activated mast cells upregulated and resting mast cells downregulated in lesional tissue. Tryptase/Chymase positive mast cells (identified using IHC) localize adjacent to epithelialized tunnels, fibrotic regions of the dermis and at perivascular sites associated with Neutrophil Extracellular Trap formation and TNF-alpha production. Treatment with Spleen Tyrosine Kinase antagonist (Fostamatinib) reduces the expression of mast cell-associated gene transcripts, associated biochemical pathways and the number of tryptase/chymase positive mast cells in lesional hidradenitis suppurativa tissue. This data indicates that although mast cells are not the most abundant cell type in Hidradenitis Suppurativa tissue, the dysregulation of mast cells is paralleled with B cell/plasma cell inflammation, inflammatory epithelialized tunnels and epithelial budding. This provides an explanation as to the mixed inflammatory activation signature seen in HS, the correlation with dysregulated wound healing and potential pathways involved in the development of epithelialized tunnels.

Clinical characteristics and heterogeneity of generalized pustular psoriasis: A comparative study in a large retrospective cohort

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Abstract

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening skin disease and the clinical heterogeneity of which is largely unknown. Retrospective cohort analysis was conducted on hospitalized GPP patients between January 2010 and November 2022. A total of 416 patients with GPP and psoriasis vulgaris (PV) respectively were included, matched 1:1 by sex and age. The heterogeneity of GPP was stratified by PV history and age. Compared with PV, GPP was significantly associated with prolonged hospitalization (11.7 vs. 10.3 day, p < 0.001), elevated neutrophil lymphocyte ratio (NLR) (5.93 vs. 2.44, p < 0.001) and anemia (13.9% vs. 1.2%, p < 0.001). Moreover, GPP alone (without PV history) was a relatively severer subtype with higher temperature (37.6°C vs. 38.0°C, p = 0.002) and skin infections (5.2% vs. 11.4%, p = 0.019) than GPP with PV. For patients across different age, compared with juvenile patients, clinical features support a severer phenotype in middle-aged, including higher incidence of anaemia (7.5% vs. 16.0%, p = 0.023) and NLR score (3.83 vs. 6.88, p < 0.001). Interleukin-6 (r = 0.59), high density lipoprotein cholesterol (r = −0.56), albumin (r = −0.53) and C-reactive protein-to-albumin ratio (r = 0.49) were the most relevant markers of severity in GPP alone, GPP with PV, juvenile and middle-aged GPP, respectively. This retrospective cohort suggests that GPP is highly heterogeneous and GPP alone and middle-aged GPP exhibit severe disease phenotypes. More attention on the heterogeneity of this severe disease is warranted to meet the unmet needs and promote the individualized management of GPP.

Effectiveness and safety of secukinumab in Chinese patients with moderate to severe plaque psoriasis in real‐world practice

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Abstract

A number of randomized controlled trials and real-world studies have demonstrated the effectiveness and safety of secukinumab in the treatment of moderate to severe psoriasis, whereas data on a large cohort of Chinese patients in long-term real-world practice are limited. This was a single-centre, uncontrolled, single-arm, prospective, observational cohort study that included 254 psoriatic patients treated with secukinumab between September 2019 and December 2022. Demographic and clinical characteristics of patients, clinical response and adverse events were evaluated. The 75% improvement in Psoriasis Area and Severity Index score (PASI 75), PASI 90, and PASI 100 in the 300 mg secukinumab group at 12 weeks were 91.7%, 74.0% and 39.7% respectively, increasing to 94.5%, 74.5% and 47.6% at 52 weeks. High body mass index (BMI), previous exposure to biologic therapies and history of previous conventional systemic therapies were associated with lower rates of PASI response. During the study period, 68 patients reported 83 adverse events (AEs) and the most frequent AEs were eczematous lesions. Up to 14.5% patients withdrew treatment due to disease remission combined with inconvenient transportation during the COVID-19 pandemic at 52 weeks. The rate of psoriasis exacerbation after COVID-19 infection in patients treated with secukinumab was 24.3% (17/70). This real-world study confirmed the high effectiveness of secukinumab in Chinese patients with moderate to severe plaque psoriasis, with an acceptable safety profile.

Generalized pustular psoriasis‐like widespread eruption following COVID‐19 infection in a patient with spondyloarthropathy on adalimumab

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Abstract

Generalized pustular psoriasis (GPP) is a form of pustular psoriasis that is distinguished by recurring or persistent outbreaks of non-acral primary sterile pustules. These eruptions can occur with or without systemic inflammation. Various factors, such as medications, stress and viral infection, have been identified as potential triggers for GPP flares. While several cases have detailed GPP-like eruptions in the setting of coronavirus disease 2019 (COVID-19) infection, few have explored the interplay between infection and biologic use in the development of GPP. In this case, we detail the history and management of a 45-year-old male patient with a prior history of spondyloarthropathy managed on a tumour necrosis factor-α inhibitor and recent COVID-19 infection presenting with a new, spreading pustular rash.