Interleukin-4 (C-589T) and Interleukin-17 (-197 G>A) Gene Polymorphisms in Psoriasis patients in Thi-Qar province south of Iraq

Abstract

Psoriasis is the common immune-mediated skin diseases which caused by the interaction between genetic and environmental risk factors. The present study aimed to determine the relationship between IL-17 (-197G>A) and IL-4 (C-589T) polymorphisms and susceptibility to psoriasis. This study included 100 patients and 50 healthy. 2-3 ml of Blood samples were collected in EDTA tube and preserved at -20 temperature for DNA extraction. IL-4 and IL-17 were amplified by Polymerase Chain Reaction (PCR) technique. In this study, 45% of psoriasis patients and 50% of healthy possessed GG genotype of IL-17 (-197 G>A) (wild genotype). 35% of patients and 30% of healthy have GA genotypes with non-significant differences compared to wild genotype (OR=0.77, 95% CI= 0.35-1.67). The same ratio of patients and healthy (20%) have homozygous AA genotype with nonsignificant differences compared to GG genotype (OR=0.90, 95% CI= 0.36-2.22). As for the IL-4, the CT and TT genotypes showed a higher frequency in the healthy group (36% and 20%, respectively) (OR=2.38, 95% CI= 1.08-5.24) compared to patients' group (22% and 14% for CT and TT, respectively (OR = 2.07, 95% CI= 0.80-5.34). The T allele frequency was 25% in psoriasis patients and 38% in the healthy group with significant differences (OR = 1.83, 95% CI= 1.09-3.07).