| Background:Psoriasis(PS), caused by excessive proliferation of inflammatory skin, is a chronic autoimmune system adjustment disorder disease which has the crowd of morbidity about 2%. The rate of overall prevalence was 0.123% according to the psoriasis epidemiological investigation in China, 1984. The current psoriasis patients should be over three million based on the investigation. Severe psoriasis not only degrades the quality of patients' life but also increases the cost of medicine. Every year in the United States, $1.6 billion were spent on psoriasis related medicines. Nevertheless, psoriasis' root cause and pathogenesis are unclear to us and the presents are still not effectively cured. Recent epidemiological studies suggest that genetic factors play an important role in psoriasis' etiology.Objectives:Based on the gene background of PS,IL-8 and IL-8R, comparing the genotype and alle frequency of some important SNP loci between healthy control and PS population, we try to find the relationship between PS and the polymorphisms of IL-8,IL-8R gene and to provide the theory foundation and laboratory dates for the diagnose, theraphy and precaution of PS.Methods:(1) The special primers were designed according to the public gene information. (2) A case-control research was done on 105 psoriasis patients as a disease group and 105 healthy individuals as a control group. DNA was extracted from peripheral blood leukocytes. (3)The gene polymorphisms were detected and analyzed by polymerase chain reaction(PCR)and restriction fragment length polymorphisms(RFLP) techniques.(4)Statistical evaluation was carried out by SPSS 13.0 statistical analysis software. Genotypes distribution underwent the Hardy-Weinberg-Equilibrium(HWE) calculation, and the control group is representative of the overall population.Results:The frequencies of the GT genotype and the G allele of IL-8R(Met31Arg) locus were 4.4% and 8.7% respectively in PS patients which are significantly increased compared with the healthy control, The P values are 0.032 and 0.003 respectively obtained by analyzing the dates with SPSS13.0. The frequency of TT genetype of IL-8R(Arg335Cys) locus in PS patients was significantly higher than that in health control group (p<0. 05). The genotypes and allele frequencies of IL-8(-251), IL-8R (Ser276)Thr were not significantly different in PS group and normal group.Conclusion:(1) The IL-8R(Met31Arg) locus may be connected with the susceptibility of PS. It can be used as a diagnose index for the susceptibility of PS.(2) The TT genetype of IL-8R(Arg335Cys)locus perhaps regulates the expression and the function of IL-8R. Then it may be connected with the development of PS.(3) The genotype and allele frequencies of IL-8(-251),IL-8R(Ser276Thr) were related to the susceptibility of PS. |
