RESUMEN
Alopeeia areata (AA) has been well recognized with familial tendencies, but the genetic basis of this clinical observation remains unknown. The cytokine interleukin-1 receptor antagonist (ILlra) is a potent anti-inflammatory protein that can prevent immune-mediated inflammatory response in the skin. We characterized a polymorphism within the gene for this cytokine ILlra in this study and tested the gene as a possible marker in patients with alopecia areata. We have determined allele frequencies of the polymorphic cytokine genes in a control population and a group of 72 patients with alopecia areata. The frequency of allele 2 of interleukin-1 receptor antagonist in patients with AA was significantly higher than that of control group. It suggests that interleukin-1 receptor antagonist gene may be a candidate gene or severity factor for alopecia areata.