Association Analysis Of IL2RA Gene With Alopecia Areata In Chinese Population

BackgroundAlopecia areata (AA) is a chronic inflammatory disorder presents with the nonscarring, circumscribed hair loss and characterized by a sudden onset and a recurrent AA is thought to be an organ-specific autoimmune disease mediated by either CD4+or CD8+T cells in which the inflammation primarily targets on immune-privileged anagen-stage hair follicles. IL2RA, also known as CD25, is highly expressed on CD4+CD25+regulatory T cells (Tregs) and is important for immune homeostasis and the suppression of autoimmune responses. The association of the IL2RA region (chromosome1Op15.1) with AA was detected with the advent of genome-wide association study (GWAS). It has been suggested that the single-nucleotide polymorphisms in IL2RA may affect the aetiopathogenesis of alopecia areata (AA).ObjectiveThe aim of the study was to investigate the link between IL2RA polymorphism and alopecia areata in the genetic homogeneous population of Han Chinese.MethodsWe examined427AA patients with AA, as well as430healthy controls in this study. DNA was purified from peripheral blood, and the rs3118470polymorphism was evaluated using high-resolution melting (HRM) analysis and direct sequencing. Demographic and clinical data obtained from the patients and controls among the genotype groups were analyzed. C/C, T/C and T/T genotypes were unambiguously distinguished with HRM technology.ResultsAmong the427patients, the prevalence of the C/C, T/C and T/T genotypes was16.2%,48.2%and35.6%, respectively. Genotyping based on HRM was fully concordant with sequencing. The genotype distribution and allele frequencies were significantly different between AA and control subjects (p<0.0001). The C allele frequency was significantly higher in the AA patients group (p<0.0001), and the frequencies of C allele and C/C genotype were higher in the patients with family history (p=0.034; p<0.0001). Differences in the distribution of both genotype (p=0.042) and alleles (p=0.049) between severe AA patients and mild AA patients reached statistical significance. According to the gender and ages of onset, there are no notable difference in the distribution of both genotype (p=0.336; p=0.854) and alleles (p=0.557; p=0.937).ConclusionsRapid and accurate genotyping analysis of IL2RA can be done with HRM. The rs3118470SNP of IL2RA may be a genetic marker to assess risk of alopecia areata in Chinese population.