A systematic investigation of confirmed autoimmune loci in early-onset psoriasis reveals an association with IL2/IL21

BACKGROUND: Many autoimmune diseases share common susceptibility loci suggesting similar underlying cellular mechanisms involved in disease expression. OBJECTIVES: The purpose of this investigation was to study 21 genetic variants in 14 genes that are confirmed autoimmune loci in a cohort of patients with early-onset psoriasis. METHODS: Patients with early-onset psoriasis (n = 750) and controls (n = 3531) were genotyped using the Sequenom(�) MassArray? iPLEX Gold platform. RESULTS: We found strong evidence of association with two variants in the IL2/IL21 (rs6822844, genotypic P = 3�3 � 10(-4) ; rs2069778, genotypic P = 7�86 � 10(-4)) region. CONCLUSIONS: The findings, although requiring replication, suggest that IL2/IL21 may play a key role in the pathogenesis of psoriasis as well as in other diverse autoimmune diseases.