The Analysis of a Genome-Wide Association Study (GWAS) of Overweight and Obesity in Psoriasis.

There is evidence that the concomitance of psoriasis and obesity may originate from the interplay between multiple genetic pathways and involve gene−gene interactions. The aim of this study was to compare the genetic background related to obesity among psoriatic patients versus healthy controls by means of a Genome-Wide Association Study (GWAS). A total of 972 psoriatic patients and a total of 5878 healthy donors were enrolled in this study. DNA samples were genotyped for over 500,000 single nucleotide polymorphisms (SNPs) using Infinium CoreExome BeadChips (Illumina, San Diego, CA, USA). Statistical analysis identified eleven signals (p < 1 × 10−5) associated with BMI across the study groups and revealed a varying effect size in each sub-cohort. Seven of the alternative alleles (rs1558902 in the FTO gene, rs696574 in the CALCRL gene, as well as rs10968110, rs4551082, rs4609724, rs9320269, and rs2338833,) are associated with increased BMI among all psoriatic patients and four (rs1556519 in the ITLN2 gene, rs12972098 in the AC003006.7 gene, rs12676670 in the PAG1 gene, and rs1321529) are associated with lower BMI. The results of our study may lead to further insights into the understanding of the pathogenesis of obesity among psoriatic patients.

Chronic Plaque Psoriasis in Poland: Disease Severity, Prevalence of Comorbidities, and Quality of Life.

The epidemiology of psoriasis has not been widely assessed in Polish population so far. This study aimed to investigate psoriasis epidemiological situation by evaluating disease course and severity, management, comorbidities, environmental factors, and knowledge about this disorder among psoriatic patients in Poland. A cross-sectional cohort population-based study enrolled 1080 psoriatic patients and 1200 controls. The mean age of psoriasis onset was 27.6 years; 78.24% had type I psoriasis. Positive family history of psoriasis was reported in 44.81% of patients, whereas itch was reported in vast majority of patients (83.33%). Based on PASI score moderate psoriasis was the most common in studied group (mean 12.63 ± 9.33, range 0−67.2). The DLQI score (12.01 ± 7.41, range 0−30.0) indicated a very large effect of psoriasis on the quality of life. Hypertension was the most prevalent comorbidity (33.80%), followed by obesity (16.85%) and dyslipidemia (11.85%). Stress was the foremost cause of disease exacerbation (66.20%); however, infections (44.07%) and seasonal changes (45.09%) had also an impact on the course of psoriasis. Psoriatic patients were more often smokers (37.59%) vs. general population (27.50%; p < 0.0001). In conclusion, epidemiological studies help clinicians in better disease and patient understanding, which may translate into better management and patient compliance.

Pathogenesis of psoriasis in the "omic" era. Part IV. Epidemiology, genetics, immunopathogenesis, clinical manifestation and treatment of psoriatic arthritis.

Psoriatic arthritis (PsA) is a chronic, progressive, inflammatory arthropathy associated with psoriasis as well as a complex pathogenesis. Genetic and environmental factors trigger the development of the immune-mediated auto-inflammatory response in different sites: skin, bone marrow, entheses and synovial tissues. Studies of the last two decades have changed the view of PsA from a mild, non-progressive arthritis to an inflammatory systemic disease with serious health consequences, not only associated with joint dysfunction, but also with an increased risk of cardiovascular disease and socioeconomic consequences with significantly reduced quality of life. The joint damage starts early in the course of the disease, thus early recognition and treatment with modern biological treatments, which may modify the natural history and slow down progression of this debilitating disease, is essential for the patient long-term outcome.

Pathogenesis of psoriasis in the "omic" era. Part III. Metabolic disorders, metabolomics, nutrigenomics in psoriasis.

Psoriasis is a systemic disease that is strictly connected with metabolic disorders (insulin resistance, atherogenic dyslipidemia, arterial hypertension, and cardiovascular diseases). It occurs more often in patients with a more severe course of the disease. Obesity is specially an independent risk factor and it is associated with a worse treatment outcome because of the high inflammatory activity of visceral fatty tissue and the production of inflammatory mediators involved in the development of both psoriasis and metabolic disorders. However, in psoriasis the activation of the Th17/IL-17 and the abnormalities in the Th17/Treg balance axis are observed, but this pathomechanism does not fully explain the frequent occurrence of metabolic disorders. Therefore, there is a need to look for better biomarkers in the diagnosis, prognosis and monitoring of concomitant disorders and therapeutic effects in psoriasis. In addition, the education on the use of a proper diet as a prophylaxis for the development of the above disorders is an important element of holistic care for a patient with psoriasis. Diet may affect gene expression due to epigenetic modification which encompasses interactions of environment, nutrition and diseases. Patients with psoriasis should be advised to adopt proper diet and dietician support.

Pathogenesis of psoriasis in the "omic" era. Part II. Genetic, genomic and epigenetic changes in psoriasis.

Psoriasis is a multifactorial disease in which genetic, environmental and epigenetic factors regulating gene expression play a key role. In the "genomic era", genome-wide association studies together with target genotyping platforms performed in different ethnic populations have found more than 50 genetic susceptible markers associated with the risk of psoriasis which have been identified so far. Up till now, the strongest association with the risk of the disease has been proved for HLA-C*06 gene. The majority of other psoriasis risk SNPs are situated near the genes encoding molecules involved in adaptive and innate immunity, and skin barrier function. Many contemporary studies indicate that the epigenetic changes: histone modification, promoter methylations, long non-coding and micro-RNA hyperexpression are considered as factors contributing to psoriasis pathogenesis as they regulate abnormal keratinocyte differentiation and proliferation, aberrant keratinocytes - inflammatory cells communication, neoangiogenesis and chronic inflammation. The circulating miRNAs detected in the blood may become specific markers in the diagnosis, prognosis and response to the treatment of the disease. The inhibition of expression in selected miRNAs may be a new promising therapy option for patients with psoriasis.

Pathogenesis of psoriasis in the "omic" era. Part I. Epidemiology, clinical manifestation, immunological and neuroendocrine disturbances.

Psoriasis is a common, chronic, inflammatory, immune-mediated skin disease affecting about 2% of the world's population. According to current knowledge, psoriasis is a complex disease that involves various genes and environmental factors, such as stress, injuries, infections and certain medications. The chronic inflammation of psoriasis lesions develops upon epidermal infiltration, activation, and expansion of type 1 and type 17 Th cells. Despite the enormous progress in understanding the mechanisms that cause psoriasis, the target cells and antigens that drive pathogenic T cell responses in psoriatic lesions are still unproven and the autoimmune basis of psoriasis still remains hypothetical. However, since the identification of the Th17 cell subset, the IL-23/Th17 immune axis has been considered a key driver of psoriatic inflammation, which has led to the development of biologic agents that target crucial elements of this pathway. Here we present the current understanding of various aspects in psoriasis pathogenesis.