Polymorphisms of PDCD1 and COL9A1 Genes in Plaque, Palmoplantar and Arthropathic Psoriasis in Romanian Patients

In recent years, genetic studies have brought new insights into psoriasis, a chronic inflammatory disease with multiple determining and favoring factors. Recent advances in the technology of genetic analysis have enabled the discovery of many loci with causal or susceptibility roles and the finding of correlations related to different types of treatment responses. In this study, genomic deoxyribonucleic acid (DNA) was extracted from 2 mL peripheral blood for the evaluation of rs10204525 for Programmed Cell Death 1 (PDCD1) gene and rs550675 for Collagen Type IX Alpha 1 Chain (COL9A1) gene in 45 psoriasis patients and 43 healthy subjects without a personal pathological history of dermatological diseases. All patients were diagnosed by clinical and histopathological examination, and the severity of disease and its impact on quality of life were evaluated by Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) scores. Comparisons were made between controls and patients, but also between different clinical types of psoriasis according to disease severity. The rank of C/T alleles for rs550675 (COL9A1 gene) was higher in the patients versus the control group (p = 0.026), while the G/A alleles for rs10204525 (PDCD1 gene) had no differences between the two groups (p = 0.450). Case and control comparisons also showed statistical significance between homozygous CC/TT genotypes (p = 0.039). After subdividing the three types of psoriasis (plaque psoriasis, arthropathic psoriasis and palmoplantar psoriasis) according to disease severity, there were differences between CC/CT genotype (p = 0.0246) and CC/TT (p = 0.007) genotype in patients with plaque psoriasis in favor of severe disease. At the same time, the GA/GG versus AA pattern was significantly higher in patients with plaque psoriasis.