High throughput screening identifies repurposable drugs for modulation of innate and acquired immune responses.

A balanced immune system is essential to maintain adequate host defense and effective self-tolerance. While an immune system that fails to generate appropriate response will permit infections to develop, uncontrolled activation may lead to autoinflammatory or autoimmune diseases. To identify drug candidates capable of modulating immune cell functions, we screened 1200 small molecules from the Prestwick Chemical Library for their property to inhibit innate or adaptive immune responses. Our studies focused specifically on drug interactions with T cells, B cells, and polymorphonuclear leukocytes (PMNs). Candidate drugs that were validated in vitro were examined in preclinical models to determine their immunomodulatory impact in chronic inflammatory diseases, here investigated in chronic inflammatory skin diseases. Using this approach, we identified several candidate drugs that were highly effective in preclinical models of chronic inflammatory disease. For example, we found that administration of pyrvinium pamoate, an FDA-approved over-the-counter anthelmintic drug, suppressed B cell activation in vitro and halted the progression of B cell-dependent experimental pemphigoid by reducing numbers of autoantigen-specific B cell responses. In addition, in studies performed in gene-deleted mouse strains provided additional insight into the mechanisms underlying these effects, for example, the receptor-dependent actions of tamoxifen that inhibit immune-complex-mediated activation of PMNs. Collectively, our methods and findings provide a vast resource that can be used to identify drugs that may be repurposed and used to promote or inhibit cellular immune responses.

Differential risks of psoriatic arthritis development in patients with varied psoriasis manifestations: a sex- and ethnicity-specific analysis.

Objectives: This study investigated psoriatic arthritis (PsA) risk across varied psoriasis manifestations, considering sex and ethnicity. Methods: Using TriNetX, a federated database encompassing over 120 million electronic health records (EHRs), we performed global retrospective cohort studies. Psoriasis vulgaris (Pso), pustulosis palmoplantaris (PPP), and generalized pustular psoriasis (GPP) cohorts were retrieved using ICD-10 codes. Propensity score matching, incorporating age, sex, and ethnicity, was employed. An alternative propensity matching model additionally included established PsA risk factors. Results: We retrieved data from 486 (Black or African American-stratified, GPP) to 35,281 (Pso) EHRs from the US Collaborative Network. Significant PsA risk variations emerged: Pso carried the highest risk [hazard ratio (HR) 87.7, confidence interval (CI) 63.4-121.1, p < 0.001], followed by GPP (HR 26.8, CI 6.5-110.1, p < 0.0001), and PPP (HR 15.3, CI 7.9-29.5, p < 0.0001). Moreover, we identified significant sex- and ethnicity-specific disparities in PsA development. For instance, compared to male Pso patients, female Pso patients had an elevated PsA risk (HR 1.1, CI 1.1-1.2, p = 0.002). Furthermore, White Pso patients had a higher likelihood of developing PsA compared to their Black or African American counterparts (HR 1.3, CI 1.04-1.7, p = 0.0244). We validated key findings using alternative propensity matching strategies and independent databases. Conclusion: This study delineates nuanced PsA risk profiles across psoriasis forms, highlighting the pivotal roles of sex and ethnicity. Integrating these factors into PsA risk assessments enables tailored monitoring and interventions, potentially impacting psoriasis patient care quality.

State-of-the-art diagnosis of autoimmune blistering diseases.

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin ß4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Risk of death, major adverse cardiac events and relapse in patients with bullous pemphigoid treated with systemic or topical corticosteroids.

BACKGROUND: According to current guidelines, systemic or topical corticosteroids are both recommended as first-line treatments for bullous pemphigoid (BP). There is evidence to suggest that topical application may be associated with a lower risk of mortality. However, there is a lack of comprehensive large-scale data comparing mortality rates, as well as the risk of major adverse cardiac events (MACE), infections and relapse, between systemic and topical corticosteroid treatments. OBJECTIVES: To evaluate the risk of death, MACE, infections and relapse in patients with BP treated with systemic or topical corticosteroids. METHODS: A population-based retrospective cohort study was performed using the TriNetX US Collaborative Network. As a measure against bias, propensity score matching for age, sex, 10 diseases and 6 medications was done, and 3 sensitivity analyses were conducted. RESULTS: All-time risk of death was increased in US patients with BP exposed to any dose of systemic corticosteroids (n = 2917) vs. patients treated with topical clobetasol propionate [n = 2932; hazard ratio (HR) 1.43, 95% confidence interval (CI) 1.28-1.58 (P < 0.001)]. This was consistent in time-stratified analysis (1- and 3-year mortality rates) and in analysis contrasting prednisone (equivalent) doses of 1-10 mg (low) or 30-100 mg (medium-high) systemic corticosteroid to topical treatment. The increased risk of death in US patients with BP exposed to any dose of systemic corticosteroids vs. topical treatment was accompanied by increased risks for MACE (HR 1.33, 95% CI 1.08-1.64; P = 0.008) and infections (HR 1.33, 95% CI 1.15-1.54; P < 0.001). The risk of continued disease or relapse was decreased in patients treated with systemic vs. topical corticosteroids (HR 0.85, 95% CI 0.77-0.94; P = 0.002). Results regarding mortality and continued disease or relapse persisted in three sensitivity analyses. Potential limitations included the retrospective data collection, bias for treatment selection and miscoding. CONCLUSIONS: Pending validation in prospective studies, where feasible - and despite the heightened risk of relapse - topical corticosteroid treatment may be advantageous over systemic corticosteroid treatment owing to its significantly lower risk of death.

Bullous pemphigoid (BP) is an autoimmune skin disease that commonly affects older people. The recommended treatment is medication called corticosteroids, either taken as a tablet or injection ('systemic') or applied to the skin ('topical'). Some evidence suggests that topical corticosteroids might be safer in terms of the risk of dying. We looked at whether there was a difference between the risk of dying, having heart problems, getting sick or the condition coming back in people with BP who use the different medications. To do this, we used people's past health information and compared people of similar ages and genders, 10 diseases and 6 medications. We found that people with BP who used systemic corticosteroids had a higher chance of dying. This also meant that people taking this form of the medication had a greater chance of having heart problems and getting infections. However, the risk of BP coming back was lower for people who used systemic corticosteroids. Our findings suggest that although there is a higher risk of BP coming back, there may be fewer risks from topical corticosteroids than systemic corticosteroids.

Prominent in vivo influence of single interneurons in the developing barrel cortex.

Spontaneous synchronous activity is a hallmark of developing brain circuits and promotes their formation. Ex vivo, synchronous activity was shown to be orchestrated by a sparse population of highly connected GABAergic 'hub' neurons. The recent development of all-optical methods to record and manipulate neuronal activity in vivo now offers the unprecedented opportunity to probe the existence and function of hub cells in vivo. Using calcium imaging, connectivity analysis and holographic optical stimulation, we show that single GABAergic, but not glutamatergic, neurons influence population dynamics in the barrel cortex of non-anaesthetized mouse pups. Single GABAergic cells mainly exert an inhibitory influence on both spontaneous and sensory-evoked population bursts. Their network influence scales with their functional connectivity, with highly connected hub neurons displaying the strongest impact. We propose that hub neurons function in tailoring intrinsic cortical dynamics to external sensory inputs.

Forward genetics and functional analysis highlight Itga11 as a modulator of murine psoriasiform dermatitis.

Psoriasis is a chronic inflammatory skin condition. Repeated epicutaneous application of Aldara® (imiquimod) cream results in psoriasiform dermatitis in mice. The Aldara®-induced psoriasiform dermatitis (AIPD) mouse model has been used to examine the pathogenesis of psoriasis. Here, we used a forward genetics approach in which we compared AIPD that developed in 13 different inbred mouse strains to identify genes and pathways that modulated disease severity. Among our primary results, we found that the severity of AIPD differed substantially between different strains of inbred mice and that these variations were associated with polymorphisms in Itga11. The Itga11 gene encodes the integrin α11 subunit that heterodimerizes with the integrin ß1 subunit to form integrin α11ß1. Less information is available about the function of ITGA11 in skin inflammation; however, a role in the regulation of cutaneous wound healing, specifically the development of dermal fibrosis, has been described. Experiments performed with Itga11 gene-deleted (Itga11-/- ) mice revealed that the integrin α11 subunit contributes substantially to the clinical phenotype as well as the histopathological and molecular findings associated with skin inflammation characteristic of AIPD. Although the skin transcriptomes of Itga11-/- and WT mice do not differ from one another under physiological conditions, distinct transcriptomes emerge in these strains in response to the induction of AIPD. Most of the differentially expressed genes contributed to extracellular matrix organization, immune system, and metabolism of lipids pathways. Consistent with these findings, we detected a reduced number of fibroblasts and inflammatory cells, including macrophages, T cells, and tissue-resident memory T cells in skin samples from Itga11-/- mice in response to AIPD induction. Collectively, our results reveal that Itga11 plays a critical role in promoting skin inflammation in AIPD and thus might be targeted for the development of novel therapeutics for psoriasiform skin conditions. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Research in practice: Diet and microbiome in autoimmune diseases.

The incidence of autoimmune diseases in industrialized countries is constantly increasing over past decades. These diseases lead to increased mortality and persistent reduction in quality of life of the patients, posing a severe medical burden. Treatment of autoimmune diseases is often based on unspecific immune suppression, increasing the risk of infectious diseases as well as cancer manifestation. Pathogenesis of autoimmune conditions is complex and includes not only genetic factors, but also environmental influence, which is considered to be the reason for the rise of incidence of autoimmune diseases. Environmental factors comprise numerous elements, such as infections, smoking, medication, diet etc., which can either promote or prevent the onset of autoimmunity. However, the mechanisms of environmental influence are complex and for this moment not clearly understood. Deciphering of these interactions could enhance our comprehension of autoimmunity and provide some novel treatment options for the patients.

Lichen sclerosus: The 2023 update.

Lichen sclerosus (LS) is an underdiagnosed inflammatory mucocutaneous condition affecting the anogenital areas. Postmenopausal women are predominantly affected and, to a lesser extent, men, prepubertal children, and adolescents. The etiology of LS is still unknown. Hormonal status, frequent trauma and autoimmune diseases are well-known associations for LS, yet infections do not seem to be clear risk factors. LS pathogenesis involves factors such as a genetic predisposition and an immune-mediated Th1-specific IFNγ-induced phenotype. Furthermore, there is a distinct expression of tissue remodeling associated genes as well as microRNAs. Oxidative stress with lipid and DNA peroxidation provides an enabling microenvironment to autoimmunity and carcinogenesis. Circulating IgG autoantibodies against the extracellular matrix protein 1 and hemidesmosome may contribute to the progression of LS or simply represent an epiphenomenon. The typical clinical picture includes chronic whitish atrophic patches along with itching and soreness in the vulvar, perianal and penile regions. In addition to genital scarring, and sexual and urinary dysfunction, LS may also lead to squamous cell carcinoma. Disseminated extragenital LS and oral LS are also reported. The diagnosis is usually clinical; however, a skin biopsy should be performed in case of an unclear clinical picture, treatment failure or suspicion of a neoplasm. The gold-standard therapy is the long-term application of ultrapotent or potent topical corticosteroids and, alternatively, topical calcineurin inhibitors such as pimecrolimus or tacrolimus. Collectively, LS is a common dermatological disease with a so far incompletely understood pathogenesis and only limited treatment options. To foster translational research in LS, we provide here an update on its clinical features, pathogenesis, diagnosis and (emerging) treatment options.

Morphea: The 2023 update.

Morphea, also known as localized scleroderma, is a chronic inflammatory connective tissue disorder with variable clinical presentations, that affects both adults and children. It is characterized by inflammation and fibrosis of the skin and underlying soft tissue, in certain cases even of the surrounding structures such as fascia, muscle, bone and central nervous system. While the etiology is still unknown, many factors may contribute to disease development, including genetic predisposition, vascular dysregulation, TH1/TH2 imbalance with chemokines and cytokines associated with interferon-γ and profibrotic pathways as well as certain environmental factors. Since the disease may progress to permanent cosmetic and functional sequelae, it is crucial to properly assess the disease activity and to initiate promptly the adequate treatment, thus preventing subsequent damage. The mainstay of treatment is based on corticosteroids and methotrexate. These, however, are limited by their toxicity, especially if applied long-term. Furthermore, corticosteroids and methotrexate often do not sufficiently control the disease and/or the frequent relapses of morphea. This review presents the current understanding of morphea by discussing its epidemiology, diagnosis, management and prognosis. In addition, it will describe recent pathogenetic findings, thus proposing potential novel targets for therapeutic development in morphea.

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV).

BACKGROUND: Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans. OBJECTIVES: These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included. RESULTS: Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients. CONCLUSIONS: These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

Impact of diet and host genetics on the murine intestinal mycobiome.

The mammalian gut is home to a diverse microbial ecosystem, whose composition affects various physiological traits of the host. Next-generation sequencing-based metagenomic approaches demonstrated how the interplay of host genetics, bacteria, and environmental factors shape complex traits and clinical outcomes. However, the role of fungi in these complex interactions remains understudied. Here, using 228 males and 363 females from an advanced-intercross mouse line, we provide evidence that fungi are regulated by host genetics. In addition, we map quantitative trait loci associated with various fungal species to single genes in mice using whole genome sequencing and genotyping. Moreover, we show that diet and its' interaction with host genetics alter the composition of fungi in outbred mice, and identify fungal indicator species associated with different dietary regimes. Collectively, in this work, we uncover an association of the intestinal fungal community with host genetics and a regulatory role of diet in this ecological niche.

Transparent Exploration of Machine Learning for Biomarker Discovery from Proteomics and Omics Data.

Biomarkers are of central importance for assessing the health state and to guide medical interventions and their efficacy; still, they are lacking for most diseases. Mass spectrometry (MS)-based proteomics is a powerful technology for biomarker discovery but requires sophisticated bioinformatics to identify robust patterns. Machine learning (ML) has become a promising tool for this purpose. However, it is sometimes applied in an opaque manner and generally requires specialized knowledge. To enable easy access to ML for biomarker discovery without any programming or bioinformatics skills, we developed "OmicLearn" (http://OmicLearn.org), an open-source browser-based ML tool using the latest advances in the Python ML ecosystem. Data matrices from omics experiments are easily uploaded to an online or a locally installed web server. OmicLearn enables rapid exploration of the suitability of various ML algorithms for the experimental data sets. It fosters open science via transparent assessment of state-of-the-art algorithms in a standardized format for proteomics and other omics sciences.

Management and treatment outcome of DRESS patients in Europe: An international multicentre retrospective study of 141 cases.

BACKGROUND: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but potentially fatal drug hypersensitivity reaction. OBJECTIVE: To explore treatment approaches across Europe and their impact on the disease course, as well as prognostic factors and culprit drugs. METHODS: In this retrospective European multicentric study, we included patients with probable or certain DRESS (RegiSCAR score ≥ 4) between January 2016 and December 2020. Independent associations between clinical parameters and the risk of intensive care unit admission and mortality at three months were assessed using a multivariable-adjusted logistic regression model. RESULTS: A total of 141 patients from 8 tertiary centres were included. Morbilliform exanthem was the most frequent cutaneous manifestation (78.0%). The mean affected body surface area (BSA) was 67%, 42% of the patients presented with erythroderma, and 24.8% had mucosal involvement. Based on systemic involvement, 31.9% of the patients had a severe DRESS. Anticonvulsants (24.1%) and sulphonamides (22.0%) were the most frequent causative agents. In all, 73% of the patients were treated with systemic glucocorticoids, and 25.5% received topical corticosteroids as monotherapy. Few patients received antiviral drugs or anti-IL5. No patients received intravenous immunoglobulins. The overall mortality was 7.1%. Independent predictors of mortality were older age (≥57.0 years; fully adjusted OR, 9.80; 95% CI, 1.20-79.93; p = 0.033), kidney involvement (fully adjusted OR, 4.70; 95% CI, 1.00-24.12; p = 0.049), and admission in intensive care unit (fully adjusted OR, 8.12; 95% CI, 1.90-34.67; p = 0.005). Relapse of DRESS and delayed autoimmune sequelae occurred in 8.5% and 12.1% of patients, respectively. CONCLUSIONS: This study underlines the need for diagnostic and prognostic scores/markers as well as for prospective clinical trials of drugs with the potential to reduce mortality and complications of DRESS.