Protein network and pathway analysis in a pharmacogenetic study of cyclosporine treatment response in Greek patients with psoriasis.

Although cyclosporine comprises a well-established systemic therapy for psoriasis, patients show important heterogeneity in their treatment response. The aim of our study was the pharmacogenetic analysis of 200 Greek patients with psoriasis based on the cyclosporine pathway related protein-protein interaction (PPI) network, reconstructed through the PICKLE meta-database. We genotyped 27 single nucleotide polymorphisms, mapped to 22 key protein nodes of the cyclosporine pathway, via the utilization of the iPLEX®GOLD panel of the MassARRAY® System. Single-SNP analyses showed statistically significant associations between CALM1 rs12885713 (P = 0.0108) and MALT1 rs2874116 (P = 0.0006) polymorphisms with positive response to cyclosporine therapy after correction for multiple comparisons, with the haplotype analyses further enhancing the predictive value of rs12885713 as a pharmacogenetic biomarker for cyclosporine therapy (P = 0.0173). Our findings have the potential to improve our prediction of cyclosporine efficacy and safety in psoriasis patients, as well as provide the framework for the pharmacogenetics of biological therapies in complex diseases.

Characteristics of psoriasis in Greece: an epidemiological study of a population in a sunny Mediterranean climate.

Psoriasis is a chronic inflammatory skin disease with important socioeconomic consequences. Data on psoriasis prevalence in Greece is scarce and circumstantially reported. The aim of this study was the recording of psoriatic patients' demographic data, clinical characteristics of the disease, and exacerbating factors. Seven hundred and eighty four patients were enrolled in 6 centres (4 in Athens and 2 in Thessaloniki) in a multicenter epidemiologic prospective study. The mean age of patients was 43.2 (standard deviation, SD 17.44) years (median 42 years), while the men: women ratio was 1.8:1. Additionally, 35% of patients reported a positive family history of psoriasis. The mean age of patients at the first episode of psoriasis was 31.3 (SD 16.39) years (median 28 years). Psoriasis vulgaris was the most common form of psoriasis in the population participating in this study. Flares of psoriasis occurred 2.6 times per year on average. The patients considered stress as the main cause for psoriasis exacerbation. Most frequent target points of psoriasis included elbows, legs, scalp and knees. The most common symptoms reported were scaling, and itching. On average, patients visited dermatologists 2.4 times per year for issues related to psoriasis. This study provides epidemiological information regarding psoriasis in Greece. Results of this survey could assist in delineation of patient profiles, and improve communication between doctors and patients.

Pharmacogenetic analysis of TNF, TNFRSF1A, and TNFRSF1B gene polymorphisms and prediction of response to anti-TNF therapy in psoriasis patients in the Greek population.

BACKGROUND: Although biologic therapies have revolutionized the treatment of psoriasis, patients exhibit a substantial heterogeneous response that could be due to complex genetic heterogeneity. OBJECTIVE: The aim of this study was to investigate the possible influence of tumor necrosis factor-α (TNF), TNF receptor I (TNFRSF1A), and TNF receptor II (TNFRSF1B) gene polymorphisms on anti-TNF treatment responsiveness in psoriasis patients. METHODS: A Greek multicenter collaboration was established to recruit a cohort of patients (n = 80) with psoriasis treated with anti-TNF drugs. Single nucleotide polymorphisms (SNPs) in TNF (-238G>A, -308G>A, -857C>T), TNFRSF1A (36A>G), and TNFRSF1B (676T>G) were genotyped by PCR-restriction fragment length polymorphism assays. SNPs and haplotypes, including stratification by comorbidity status, were analyzed for association with treatment response after 6 months of therapy, defined as a reduction in the Psoriasis Area and Severity Index (PASI) score by >75% (responders) or ≤50% (nonresponders). RESULTS: Sixty-three patients (78.8%) were defined as responders (PASI score reduction >75%) and 17 patients (21.2%) were defined as nonresponders (PASI score reduction ≤50%). Carriage of TNF -857C or TNFRSF1B 676T alleles was associated with positive response to drug treatment in patients treated with etanercept (p = 0.002 and p = 0.001, respectively). None of the genotyped SNPs were associated with responsiveness to treatment with infliximab or adalimumab. Additionally, when patients were stratified by comorbidity status, none of the genotyped SNPs were alone associated with responsiveness to drug treatment. CONCLUSION: This study is the first in the field of psoriasis demonstrating a strong association between genetic markers and positive response to drug treatment. Validation of this result in larger studies, as well as analysis of other drug treatments, could provide the basis for individually tailored treatment, along with increased cost effectiveness and reduced unnecessary exposure to toxicity.