Association of KIR2DL5, KIR2DS5, and KIR2DS1 allelic variation and atopic dermatitis.

Natural killer cells (NK) have been associated with the pathophysiology of atopic dermatitis (AD). NK function is regulated by killer cell Ig-like receptor family (KIR) receptors that interact with HLA ligands. The study goal was to focus on allelic variation in genes KIR2DL5, KIR2DS5, and KIR2DS1 with respect to AD. This was a case-control study of individuals with (n = 313) and without (n = 176) AD. Associations were estimated using logistic regression. The prevalence of KIR2DL5 was 52.5% (95% CI 48.0,57.0), KIR2DS5 was 33.0% (28.8,37.3), and KIR2DS1 was 33.6% (29.4,38.0). The presence of the KIR2DL5001:01 increased the odds of having AD by about 86% (odds ratio (OR): 1.86(1.23,2.82) p = 0.003). The risk for individuals homozygous for KIR2DL5001:01 was even greater (OR: 2.16 (95% CI 1.31,3.53) p = 0.0023). The odds of having AD with KIR2DL5001:01 was similar in Whites and Blacks. Allelic variation in KIR2DS5 and KIR2DS1 was not associated with AD. There is no known HLA binding ligand for KIR2DL5. The effect of KIR2DL5001:01 increased in the presence of HLA-B*-21TT leader sequence (2.46(1.37,4.41) p = 0.0025) and the HLA-C2 ligand (2.07 (1.37,4.41, p = 0.000002). Our study shows an independent association of the KIR2DL5*001:01 with AD and is the first study to associate AD with KIR allelic variation.