Association Study Of IL1RL1 Gene Polymorphism And Clinical Features Of Psoriasis In Chinese Han Population

Background Psoriasis is a chronic inflammatory disease of skin characterized by well-demarcated, erythematous,and(or)thickened plaques with overlying scale. Now, the etiology and pathogenesis of the disease remains unclear. It is a multifactorial disorder, influenced by genetic, immune and environmental factors. For the family as the basis for the genetics of psoriasis, genetic prominent role in the epidemiological investigation of psoriasis, it has significant familial aggregation, many psoriasis susceptibility loci have been identified successfully through a genome-wide association study(GWAS). It is currently believed that both the adaptive and innate immune systems play important roles in pathogenesis of psoriasis.The various cell types observed within psoriatic lesions include keratinocytes(KC), dendritic cells(DC), monocytes, macrophages, and T and B lymphocytes. Known environmental triggers, such as infection, stress, excess body weight, medications, cigarette smoking, excessive alcohol intake, and even weather and climate, can induce or exacerbate psoriasis in many patients. According to World Psoriasis Day consortium, psoriasis affects 3% of the world’s population, approximately 125 million people. In recent years, we identified rs1420101 at L1RL1 was significantly associated with psoriasis in the Chinese Han population by whole exome chip(P=1.71 ×10-10, OR=0.88,95%CI=0.84~0.91). The study aims to investigate the correlation between IL1RL1 single-nucleotide polymorphism rs1420101 and subphenotypes of PV.Objective According to the stratifying analysis of the age of onset, severity, family history and clinical types, to explore the relationship between IL1RL1 gene polymorphism rs1420101 and PV clinical phenotype, and to provide the mechanism andthe foundation for further elucidate the genetic pathogenesis of PV.Methods In this study, we used 9,390 cases and 10,800 controls from our previous exome-wide chip to explore the association of rs1420101 with subphenotypes of psoriasis. Data were analyzed with the SPSS software(Version 20.0).Results The case only analysis according to family history, age of onset, disease type, severity of disease, analysis of frequency and genotype distribution of IL1RL1 gene rs1420101 in groups, Significant associations were observed with guttate psoriasis(P=3.09×10-3,OR=1.11,95%CI=1.04~1.19) in the stratified analyses. Another significant difference was observed in the late-onset psoriasis(P=3.93×10-2, OR=1.10, 95%CI=1.01~ 1.19).No statistical significance between the two groups compared with positive family history of PV patients and negative family history of PV patients(P = 5.94×10-1,OR=1.02, 95%CI=0.94~1.11).No statistical significance between mild and moderate(P=7.38× 10-2,OR=1.12,95%CI=0.99~1.26).No statistical significance between severe and moderate(P=8.04×10-2,OR=0.89,95%CI= 0.78 ~ 1.01).Conclusions The study suggested that rs1420101 might not only play an important role in the development of psoriasis, but also contribute to the disease types of psoriasis.These results indicated that the risk allele G of rs1420101(IL1RL1) imparted significant risk towards the guttate psoriasis in the Chinese Han population.and associated with age of onset and skin lesion type.