IL18 and adult-onset Still disease: However, a potential genetic etiology for AOSD is proposed.[57] HLA DQ B1* 0602 (DQ1) is commonly identified in Japanese patients with AOSD.[58] In addition, the IL-18 S01 haplotype is more prevalent in patients with AOSD than in healthy individuals.[59] Therefore, these genetic factors may contribute to the high incidence of elderly AOSD in Asians, particularly in those of Japanese descent.