Infections and the risk of psoriatic arthritis among psoriasis patients: a systematic review

3D chromatin-based variant-to-gene maps across 57 human cell types reveal the cellular and genetic architecture of autoimmune disease susceptibility

A portion of the genetic basis for many common autoimmune disorders has been uncovered by genome-wide association studies (GWAS), but GWAS do not reveal causal variants, effector genes, or the cell types impacted by disease-associated variation. We have generated 3D genomic datasets consisting of promoter-focused Capture-C, Hi-C, ATAC-seq, and RNA-seq and integrated these data with GWAS of 16 autoimmune traits to physically map disease-associated variants to the effector genes they likely regulate in 57 human cell types. These 3D maps of gene cis-regulatory architecture are highly powered to identify the cell types most likely impacted by disease-associated genetic variation compared to 1D genomic features, and tend to implicate different effector genes than eQTL approaches in the same cell types. Most of the variants implicated by these cis-regulatory architectures are highly trait-specific, but nearly half of the target genes connected to these variants are shared across multiple autoimmune disorders in multiple cell types, suggesting a high level of genetic diversity and complexity among autoimmune diseases that nonetheless converge at the level of target gene and cell type. Substantial effector gene sharing led to the common enrichment of similar biological networks across disease and cell types. However, trait-specific pathways representing potential areas for disease-specific intervention were identified. To test this, we pharmacologically validated squalene synthase, a cholesterol biosynthetic enzyme encoded by the FDFT1 gene implicated by our approach in MS and SLE, as a novel immunomodulatory drug target controlling inflammatory cytokine production by human T cells. These data represent a comprehensive resource for basic discovery of gene cis-regulatory mechanisms, and the analyses reported reveal mechanisms by which autoimmune-associated variants act to regulate gene expression, function, and pathology across multiple, distinct tissues and cell types.

The Role of Epigenetic Factors in the Pathogenesis of Psoriasis

Psoriasis is a chronic inflammatory skin disease, the prevalence of which is increasing. Genetic, genomic, and epigenetic changes play a significant role in the pathogenesis of psoriasis. This review summarizes the impact of epigenetics on the development of psoriasis and highlights challenges for the future. The development of epigenetics provides a basis for the search for genetic markers associated with the major histocompatibility complex. Genome-wide association studies have made it possible to link psoriasis to genes and therefore to epigenetics. The acquired knowledge may in the future serve as a solid foundation for developing newer, increasingly effective methods of treating psoriasis. In this narrative review, we discuss the role of epigenetic factors in the pathogenesis of psoriasis.

Multiple environmental antigens may trigger autoimmunity in psoriasis through T-cell receptor polyspecificity

Introduction

Psoriasis is a T-cell mediated autoimmune skin disease. HLA-C*06:02 is the main psoriasis-specific risk gene. Using a Vα3S1/Vβ13S1 T-cell receptor (TCR) from a lesional psoriatic CD8+ T-cell clone we had discovered that, as an underlying pathomechanism, HLA-C*06:02 mediates an autoimmune response against melanocytes in psoriasis, and we had identified an epitope from ADAMTS-like protein 5 (ADAMTSL5) as a melanocyte autoantigen. The conditions activating the psoriatic autoimmune response in genetically predisposed individuals throughout life remain incompletely understood. Here, we aimed to identify environmental antigens that might trigger autoimmunity in psoriasis because of TCR polyspecificity.

Methods

We screened databases with the peptide recognition motif of the Vα3S1/Vβ13S1 TCR for environmental proteins containing peptides activating this TCR. We investigated the immunogenicity of these peptides for psoriasis patients and healthy controls by lymphocyte stimulation experiments and peptide-loaded HLA-C*06:02 tetramers.

Results

We identified peptides from wheat, Saccharomyces cerevisiae, microbiota, tobacco, and pathogens that activated both the Vα3S1/Vβ13S1 TCR and CD8+ T cells from psoriasis patients. Using fluorescent HLA-C*06:02 tetramers loaded with ADAMTSL5 or wheat peptides, we find that the same CD8+ T cells may recognize both autoantigen and environmental antigens. A wheat-free diet could alleviate psoriasis in several patients.

Discussion

Our results show that due to TCR polyspecificity, several environmental antigens corresponding to previously suspected psoriasis risk conditions converge in the reactivity of a pathogenic psoriatic TCR and might thus be able to stimulate the psoriatic autoimmune response against melanocytes. Avoiding the corresponding environmental risk factors could contribute to the management of psoriasis.

The Saudi consensus recommendations for the management of psoriatic arthritis (2023)

Psoriatic arthritis (PsA) is a complex inflammatory disease characterized by musculoskeletal and non-musculoskeletal manifestations. It is a distinct disease entity at the interface between rheumatology and dermatology, making it challenging to manage. The diverse clinical presentation and severity of PsA require a multidisciplinary approach for optimal care. Early diagnosis and management are necessary to improving quality of life for patients. In Saudi Arabia, there is currently no unified national consensus on the best practices for managing PsA. This lack of consensus leads to debate and uncertainty in the treatment of the disease, resulting in over or under prescribing of biological agents. To address this issue, a multidisciplinary work group was formed by the Saudi Ministry of Health. This group, consisting of dermatologists, rheumatologists, and pharmacists, aimed to develop evidence-based consensus recommendations for he use and monitoring of biological therapy in PsA management. The work group conducted five consensus workshops between December 2021 to March 2022. Using the nominal group technique, they discussed various aspects of PsA management, including eligibility criteria for biological treatment, monitoring of disease activity, treatment goals, screening, precautions, and management of PsA with biologic therapies. The group also considered special considerations for patients with comorbidities, pregnant and lactating women, as well as pediatric and adolescent populations. The resulting consensus document provides recommendations that are applicable to the Saudi setting, taking into account international guidelines and the specific needs of PsA patients in the country. The consensus document will be regularly updated to incorporate new data and therapeutic agents as they become available. Key Points • In Saudi Arabia, there is a lack of unified national consensus on the optimal management of PsA, therefore, this article aims to provide up-to-date evidence-based consensus recommendations for the optimal use and monitoring of biologic therapy in the management of PsA in Saudi Arabia. • The consensus development process was undertaken by a multidisciplinary work group of 13 experts, including two dermatologists, six rheumatologists, and five pharmacists. • There is more than one disease activity tool used in PsA disease, depending on the disease domain - peripheral arthritis Disease Activity Index in Psoriatic Arthritis (DAPSA) or Minimal Disease Activity (MDA), axial PsA Ankylosing Spondylitis Disease Activity Score (ASDAS), and dactylitis and enthesitis MDA. • The main goal of therapy in all patients with PsA is to achieve the target of remission, or alternatively, low disease activity in all disease domains and improve quality of life (QoL).

Strong site-specific association of pharyngeal cultures with the onset of psoriatic arthritis and psoriasis, regardless of pathogen

OBJECTIVES

The objective of this study was to evaluate any association between culture site / culture result / pathogen and incident PsA or psoriasis.

METHODS

Records of all samples sent for culture from a large population during a 3-year period were linked with nationwide registry data on diagnoses and death over a 15-year period. The main outcomes of interest were incident diagnoses of PsA and psoriasis, defined by International Classification of Diseases (ICD) codes. The effect of culture site, culture result (positive vs negative), and pathogen (Streptococcus vs negative culture) on the risk of developing PsA and psoriasis was calculated using Cox proportional hazards models adjusted for age and gender.

RESULTS

A total of 313 235 bacterial cultures from 128 982 individuals were analysed. Comparing individuals with pharyngeal cultures to those with urine cultures, the hazard ratio for incident PsA was 8.78 [95% confidence interval (CI) 3.23, 23.91] and for incident psoriasis it was 8.00 (95% CI 5.28, 12.12). Most of the risk was concentrated in the first 50 days after the culture date. Increased risk was also found when comparing individuals with cultures from the pharynx with those with cultures from the nasopharynx and blood. An association with streptococci was not found, neither in the pharynx nor at any other site. A positive bacterial culture from any site was associated with reduced risk for both PsA and psoriasis.

CONCLUSION

There is a strong site-specific association between pharyngeal culture samples and an increased risk of PsA and psoriasis, regardless of the pathogen. This may indicate that the site of infection, rather than the pathogen, is associated with increased risk.

Do genetics contribute to TNF inhibitor response prediction in Psoriatic Arthritis?

Psoriatic arthritis (PsA) is a heterogeneous chronic musculoskeletal disease, affecting up to 30% of people with psoriasis. Research into PsA pathogenesis has led to the development of targeted therapies, including Tumor Necrosis Factor inhibitors (TNF-i). Good response is only achieved by ~60% of patients leading to 'trial and error' drug management approaches, adverse reactions and increasing healthcare costs. Robust and well-validated biomarker identification, and subsequent development of sensitive and specific assays, would facilitate the implementation of a stratified approach into clinical care. This review will summarise potential genetic biomarkers for TNF-i (adalimumab, etanercept and infliximab) response that have been reported to date. It will also comment upon the importance of managing clinical confounders when understanding drug response prediction. Variants in multiple gene regions including TNF-A, FCGR2A, TNFAIP3, TNFR1/TNFR1A/TNFRSF1A, TRAIL-R1/TNFRSF10A, FCGR3A have been reported to correlate with TNF-i response at various levels of statistical significance in patients with PsA. However, results were often from heterogenous and underpowered cohorts and none are currently implemented into clinical practice. External validation of genetic biomarkers in large, well-documented cohorts is required, and assessment of the predictive value of combining multiple genetic biomarkers with clinical measures is essential to clinically embed pharmacogenomics into PsA drug management.

Natural Hemp-Ginger Extract and Its Biological and Therapeutic Efficacy

The prevention and treatment of skin diseases remains a major challenge in medicine. The search for natural active ingredients that can be used to prevent the development of the disease and complement treatment is on the rise. Natural extracts of ginger and hemp offer a wide range of bioactive compounds with potential health benefits. This study evaluates the effectiveness of hemp and ginger extract as a supportive treatment for skin diseases. It reports a synergistic effect of hemp and ginger extract. The contents of cannabinoids and components of ginger are determined, with the highest being CBD (587.17 ± 8.32 µg/g) and 6-gingerol (60.07 ± 0.40 µg/g). The minimum inhibitory concentration for Staphylococcus aureus (156.5 µg/mL), Escherichia coli (625.2 µg/mL) and Candida albicans (78.3 µg/mL) was also analyzed. Analysis of WM-266-4 cells revealed the greatest decrease in metabolic activity in cells exposed to the extract at a concentration of 1.00 µg/mL. Regarding the expression of genes associated with cellular processes, melanoma aggressiveness, resistance and cell survival, a significant difference was found in the expression of ABCB5, CAV1 and S100A9 compared with the control (cells not exposed to the extract).

A case report of monoarthritis in a COVID-19 patient and literature review: Simple actions for complex times

RATIONALE

COVID-19 presentation is multifaceted and up to 44% of patients affected by COVID-19 experience musculoskeletal complaints, mostly in the form of diffuse aspecific arthromyalgias. Nevertheless, only a few cases of arthritis following SARS-CoV2 infection are reported.

PATIENT CONCERNS

A 27-year-old man affected by nail psoriasis presented with monoarthritis 2 weeks after being diagnosed with COVID-19.

DIAGNOSES

Diagnostic work-up and differential diagnosis were made difficult by patient isolation, absence of lab tests, and his visit via telemedicine, even though signs of first metacarpophalangeal joint involvement were clear.

INTERVENTIONS

Due to the inefficacy of acetaminophen and nonsteroidal anti-inflammatory drugs, the patient was prescribed oral steroids with a rapid benefit.

OUTCOMES

The patient's response to oral steroid was prompt and maintained even after therapy tapering. Even so, a formal diagnosis was not possible due to a difficult diagnostic work-up and lack of a long-term follow-up.

LESSONS

Like many other viral diseases, SARS-CoV2 can play as a causative agent or as a trigger for inflammatory arthritis development in predisposed individuals.

Psoriatic arthritis: A systematic review of non-HLA genetic studies and important signaling pathways

Psoriatic arthritis (PsA) is a common, chronic inflammatory disease with complex pathogenesis. In recent years, a number of susceptibility non-human leukocyte antigen (HLA) genes of PsA have been revealed, which also act as important factors in the pathogenesis of PsA as well as HLA genes. By searching the databases National Center for Biotechnology Information, Google and PubMed, 37 articles are included and 50 susceptibility non-HLA genes for PsA are presented, such as IL23A, TNIP1, TYK2, STAT4, IL12B, RUNX3 and TRAF3IP2. In these non-HLA genes, some are common genes shared with other diseases, whereas most of these susceptibility genes are related to the pathogenesis of PsA by activation or inhibition of the signaling pathways. Several signaling pathways possibly implicated in the pathogenesis of PsA are introduced in this paper, including the 2 mainly signaling pathways, IL23/Th17 signaling pathway and NF-κB signaling pathway, and the other involved signaling pathways, such as JAK-STAT signaling pathway and MAPK signaling pathway.

Gut microbiota and nutrient interactions with skin in psoriasis: A comprehensive review of animal and human studies

The intestinal tract (i.e., the gut), is where the body’s nutrients are absorbed, and is simultaneously inhabited by numerous microbes. An increasing body of literature suggests a crucial role for the gut microbiome in modulating systemic inflammatory disease. Psoriasis is a chronic systemic inflammatory disease and its pathogenesis is related to the interaction between genetic susceptibility, immune response and environmental triggers. The omics era has allowed physicians to assess different aspects of psoriasis pathogenesis such as the microbiome, infectome, and autoinfectome. Furthermore, diet appears to play an important role in modulating disease activity, perhaps by influencing gut microbes. Given these observations, we aimed to summarize the current knowledge regarding skin-microbiome-gut-nutrients and psoriasis.

Acute onset of psoriatic spondyloarthritis as a new manifestation of post-streptococcal reactive arthritis: a case series

Streptococcus is well associated with a myriad of inflammatory diseases. Among others, this bacterium is linked to the triggering of psoriasis and to post-streptococcal reactive arthritis (PSRA), an arthritis which is typically confined to peripheral joints. Three patients who developed acute psoriatic spondyloarthritis (SpA) following a recent streptococcal infection are described in this article. We searched the existing literature for cases of axial involvement in PSRA and reviewed the association between streptococcal infection and psoriasis or psoriatic arthritis )PsA). In all patients, psoriatic SpA occurred within 7-10 days of a confirmed streptococcal infection. The main presenting syndrome was inflammatory back pain with evidence of acute axial spondyloarthritis on magnetic resonance imaging. One patient had guttate psoriasis, the second patient developed pustular psoriasis, and the third patient had exacerbation of pustular palmoplantar psoriasis. Two patients required treatment with tumor necrosis factor alpha (TNF-α) blockers. Axial involvement in PSRA is very rare. A potential association of streptococcal infection and development of PsA has been explored in several articles. However, to the best of our knowledge, acute psoriatic SpA as a manifestation of PSRA has yet to be described. Acute psoriatic SpA should be considered in the differential diagnosis of new-onset inflammatory back pain followed by psoriasis in young adults who had a recent throat infection. KEY POINTS: • Our case series describes three cases of acute psoriatic spondyloarthritis that occurred within 7--10 days of a confirmed streptococcal infection and progressed to full blown chronic disease. • Acute psoriatic spondyloarthritis as a manifestation of post streptococcal reactive arthritis should be considered in the differential diagnosis of new onset inflammatory back pain followed by psoriasis in young adults who had a recent throat infection.