Investigation of 36 non-HLA (human leucocyte antigen) psoriasis susceptibility loci in a psoriatic arthritis cohort

Psoriasis and Psoriatic Arthritis-Associated Genes, Cytokines, and Human Leukocyte Antigens

In recent years, research has intensified in exploring the genetic basis of psoriasis (PsO) and psoriatic arthritis (PsA). Genome-wide association studies (GWASs), including tools like ImmunoChip, have significantly deepened our understanding of disease mechanisms by pinpointing risk-associated genetic loci. These efforts have elucidated biological pathways involved in PsO pathogenesis, particularly those related to the innate immune system, antigen presentation, and adaptive immune responses. Specific genetic loci, such as TRAF3IP2, REL, and FBXL19, have been identified as having a significant impact on disease development. Interestingly, different genetic variants at the same locus can predispose individuals to either PsO or PsA (e.g., IL23R and deletion of LCE3B and LCE3C), with some variants being uniquely linked to PsA (like HLA B27 on chromosome 6). This article aims to summarize known and new data on the genetics of PsO and PsA, their associated genes, and the involvement of the HLA system and cytokines.

Psoriatic Arthritis: Development, Detection and Prevention: A Scoping Review

Psoriatic arthritis is a heterogenous chronic inflammatory disease that develops over time in some patients with psoriasis. The course of the disease is variable, with a broad clinical spectrum. The management of PsA has changed tremendously over the last decade, thanks to earlier diagnosis, a multidisciplinary approach and progress in pharmacological therapies. Therefore, screening for risk factors and the early signs of arthritis is highly important and recommended. Currently, research is focused on finding soluble biomarkers and developing imaging techniques that can improve the prediction of psoriatic arthritis. Among imaging modalities, ultrasonography seems to be the most accurate in detecting subclinical inflammation. Early intervention is based on the assumption that it is possible to prevent or delay psoriatic arthritis if systemic treatment for psoriasis can be administered early enough. This review article provides an overview of the current perspectives and evidence regarding the diagnosis, management and prevention of psoriatic arthritis.

Biomarkers in psoriatic arthritis: A meta-analysis and systematic review

Introduction

Psoriatic arthritis (PsA) is a chronic inflammatory disease that frequently develops in patients with psoriasis (PsO) but can also occur spontaneously. As a result, PsA diagnosis and treatment is commonly delayed, or even missed outright due to the manifold of clinical presentations that patients often experience. This inevitably results in progressive articular damage to axial and peripheral joints and entheses. As such, patients with PsA frequently experience reduced expectancy and quality of life due to disability. More recently, research has aimed to improve PsA diagnosis and prognosis by identifying novel disease biomarkers.

Methods

Here, we conducted a systematic review of the published literature on candidate biomarkers for PsA diagnosis and prognosis in MEDLINE(Pubmed), EMBase and the Cochrane library with the goal to identify clinically applicable PsA biomarkers. Meta-analyses were performed when a diagnostic bone and cartilage turnover biomarker was reported in 2 or moredifferent cohorts of PsA and control.

Results

We identified 1444 publications and 124 studies met eligibility criteria. We highlighted bone and cartilage turnover biomarkers, genetic markers, and autoantibodies used for diagnostic purposes of PsA, as well as acute phase reactant markers and bone and cartilage turnover biomarkers for activity or prognostic severity purposes. Serum cartilage oligometrix metalloproteinase levels were significantly increased in the PsA sera compared to Healthy Control (HC) with a standardized mean difference (SMD) of 2.305 (95%CI 0.795-3.816, p=0.003) and compared to osteoarthritis (OA) with a SMD of 0.783 (95%CI 0.015-1.551, p=0.046). The pooled serum MMP-3 levels were significantly higher in PsA patients than in PsO patients with a SMD of 0.419 (95%CI 0.119-0.719; p=0.006), but no significant difference was highlighted when PsA were compared to HC. While we did not identify any new genetic biomarkers that would be useful in the diagnosis of PsA, recent data with autoantibodies appear to be promising in diagnosis, but no replication studies have been published.

Conclusion

In summary, no specific diagnostic biomarkers for PsA were identified and further studies are needed to assess the performance of potential biomarkers that can distinguish PsA from OA and other chronic inflammatory diseases.

Diagnostic Test Accuracy of Genetic Tests in Diagnosing Psoriasis: A Systematic Review

The pathogenesis of psoriasis involves the interaction of several environmental and genetic factors. Predicting the disease risk cannot depend on individual genetic alleles. Consequently, some studies have evaluated the use of genetic risk scores that combine several psoriasis susceptibility loci to increase the accuracy of predicting/diagnosing the disease. This meta-analysis summarizes the evidence regarding using genetic risk scores (GRS) in the diagnosis or prediction of psoriasis. A search of MEDLINE/PubMed, the Latin American Caribbean Health Sciences Literature (LILACS) database, Cochrane Library, Scopus, Web of Science, and ProQuest was conducted in July 2022. The primary objective was to record the area under the curve (AUC) for GRS of psoriasis. Secondary objectives included characteristics of studies and patients. The risk of bias (ROB) was assessed using the PROBAST tool. Five studies fulfilled the eligibility criteria of this review. None of the studies described the clinical criteria (reference standard) that were employed to diagnose psoriasis. The AUCs of the 11 GRS models ranged from 0.6029-0.8583 (median: 0.75). Marked heterogeneity was detected (Cochran Q: 1250.051, p < 0.001, and I² index: 99.2%). So, pooling of the results of the included studies was not performed. The ROB was high for all studies and clinical application was not described. Genetic risk scores are promising tools for the prediction of psoriasis with fair to good accuracy. However, further research is required to identify the most accurate combination of loci and to validate the scores in variable ethnicities.

Cognitive Process of Psoriasis and Its Comorbidities: From Epidemiology to Genetics

Psoriasis (PsO) is a chronic inflammatory skin disease that affects approximately 2% of the population all over the world. Comorbidities of PsO have increasingly garnered more interest in the past decades. Compared with the normal population, the incidences of comorbidities are higher among patients with PsO. In the last 20 years, researchers have focused on studying the genetic components of PsO, and genetic associations between PsO and its comorbidities were elucidated. This review provides an in-depth understanding and summarization of the connection between PsO and its comorbidities from the perspectives of epidemiology and genetics. Further understanding of PsO and its comorbidities will promote research on the pathogenesis, drug development, novel therapy methods, and personalized and precision treatment of PsO and its comorbidities.

Replication study and meta-analysis indicate a suggestive association of RUNX3 locus with primary biliary cholangitis

Susceptibility to primary biliary cholangitis (PBC) is in part genetically determined. In our previous PBC genome-wide association study (GWAS) in 1118 Han Chinese PBC and 4036 controls, we noted that multiple SNPs in the runt-related transcription factor 3 (RUNX3) regions showed a nominally significant association. The tag SNP rs7529070 was genotyped using a TaqMan assay in a separately collected 1435 PBC and 3205 controls. A meta-analysis with a combined 2553 PBC and 7241 controls showed that rs7529070 is still nominally associated with PBC (p = 1.7 × 10^-4, odds ratio (OR) = 1.18, 95% confidence interval (CI) = 1.08-1.28). Further analysis indicated that the risk allele of rs7529070 (G allele) is in complete linkage disequilibrium (LD) (r² = 1) with the G allele of rs4648889, which is known to be associated with increased RUNX3 expression. Bioinformatic analysis with existing expression data showed that the expression of RUNX3 is significantly increased in PBC patients (p = 0.001) and the expression level is correlated with disease severity. Consistently, we also found significantly increased RUNX3 expression (p < 0.01) in the livers of dnTGFβRII mice (a PBC mouse model). This study suggests that the RUNX3 locus may associate with PBC in Han Chinese.

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.

Combining Understanding of Immunological Mechanisms and Genetic Variants Toward Development of Personalized Medicine for Psoriasis Patients

Psoriasis is multifactorial disease with complex genetic predisposition. Recent advances in genetics and genomics analyses have provided many insights into the relationship between specific genetic predisposition and the immunopathological mechanisms driving psoriasis manifestation. Novel approaches which utilize array-based genotyping technologies such as genome-wide association studies and bioinformatics tools for transcriptomics analysis have identified single nucleotide polymorphisms, genes and pathways that are associated with psoriasis. The discovery of these psoriasis-associated susceptibility loci, autoimmune targets and altered signaling pathways have provided opportunities to bridge the gap of knowledge from sequence to consequence, allowing new therapeutic strategies for the treatment of psoriasis to be developed. Here, we discuss recent advances in the field by highlighting how immune functions associated with psoriasis susceptibility loci may contribute to disease pathogenesis in different populations. Understanding the genetic variations in psoriasis and how these may influence the immunological pathways to cause disease will contribute to the efforts in developing novel and targeted personalized therapies for psoriasis patients.

The Protein Tyrosine Phosphatase Nonreceptor 22 (PTPN22) R620W Functional Polymorphism in Psoriasis

Background:

Psoriasis is a complex autoimmune disease caused by the interaction of genetic and environmental factors. PTPN22 gene polymorphism has been reported to affect psoriasis susceptibility; however, no data are available for Middle Eastern populations.

Objective:

The aim of this study was to investigate the association of PTPN22 (1858C/T) R620W polymorphism with psoriasis in a Saudi cohort.

Methods:

Saudi subjects (n = 306) including patients with psoriasis (n = 106) and matched controls (n = 200) were studied for PTPN22 variants using tetra-primer amplification refractory mutation system-polymerase chain reaction method. The frequencies of alleles and genotypes of PTPN22 (1858C/T) polymorphism were compared between patients and controls.

Results:

The frequency of CT genotype of PTPN22 (1858C/T) polymorphism was significantly higher, whereas that of CC genotype was lower in patients with psoriasis than in controls (P < .001, relative risk [RR] = 7.151). The homozygous genotype TT was absent in both the patients and healthy controls. The frequency of allele T encoding tryptophan (W) was significantly increased (P < .001, RR = 5.76), whereas that of allele C encoding arginine (R) decreased in psoriasis cases as compared with controls (P < .001, RR = 0.173) indicating that individuals carrying allele T are more susceptible to psoriasis than noncarriers.

Conclusions:

PTPN22 (1858C/T) polymorphism is positively associated with susceptibility of psoriasis in Saudis and can be developed as biomarker for evaluating psoriasis risk. However, further studies on PTPN22 polymorphism in larger samples from different geographical areas and ethnicity are warranted.