Association of HLA-DRB1 genetic variants with the persistence of atopic dermatitis.

Atopic dermatitis (AD) is a waxing and waning illness of childhood that is likely caused by interactions between an altered skin barrier and immune dysregulation. The goal of our study was to evaluate the association of DRB1 genetic variants and the persistence of AD using whole exome sequencing and high resolution typing. DRB1 was interrogated based on previous reports that utilized high throughput techniques. We evaluated an ongoing nation-wide long-term cohort of children with AD in which patients are asked every 6months about their medication use and their AD symptoms. In total, 87 African-American and 50 European-American children were evaluated. Genetic association analysis was performed using a software tool focusing on amino acid variable positions shared by HLA-DRB1 alleles covering the antigen presenting domain. Amino acid variations at position 9 (pocket 9), position 26, and position 78 (pocket 4) were marginally associated with the prevalence of AD. However, the odds ratio was 0.30 (0.14, 0.68; p=0.003) for residue 78, 0.27 (0.10, 0.69; p=0.006) for residue 26 and not significant for residue 9 with respect to the persistence of AD. In conclusion, amino acid variations at peptide-binding pockets of HLA-DRB1 were associated with the persistence of AD in African-American children.