The effect of IL-10 genetic variation and interleukin 10 serum levels on Crohn's disease susceptibility in a New Zealand population

Interleukin (IL)-10 has important effects in immunoregulation and inflammation, and previous studies have provided evidence for the involvement of IL-10 in the pathogenesis of Crohn's disease (CD). In this study, we investigated whether genetic variants of the IL-10 gene were associated with CD in a New Zealand population. Three single nucleotide polymorphisms (SNPs) in the promoter region of IL-10 (rs1800871, rs1800872, and rs1800896) and a flanking SNP, rs3024505, were genotyped in a well-characterized New Zealand dataset consisting of 342 CD cases and 610 controls. Furthermore, we measured serum IL-10 levels in a number of the CD patients and controls and examined whether a relationship existed between these polymorphisms and serum IL-10 levels. We demonstrated an association with CD for SNPs rs3024505 and rs1800896, and phenotypic analysis indicated an association of rs3024505 with an early age at first diagnosis, stricturing CD behavior, and requirement for bowel resection. We also observed that IL-10 concentration was significantly higher in CD patients than in the controls and that the T allele of rs1800896, the A allele of rsl 800871, and the T allele of rs1800872 were associated with increased serum IL-10 levels. (C) 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.