Association of IL1R polymorphism with HLA-B27 positive in Iranian patients with ankylosing spondylitis

作者：Mahmoudi M; Amirzargar A A; Jamshidi A R; Farhadi E; Noori S; Avraee M; Nazari B; Nicknam M H^*

来源：European Cytokine Network, 2011, 22(4): 175-180.

DOI：10.1684/ecn.2011.0293

• ankylosing spondylitis
• gene polymorphism
• IL1 gene cluster
• HLA-B27 subtypes

Objective. Ankylosing spondylitis (AS) is one of the most common causes of inflammatory arthritis, with an estimated prevalence of 0.1-0.9%. Genetic factors have been strongly implicated in its aetiology, and heritability as assessed by twin studies has been estimated to be >90%. HLA-B27 is almost essential for inheritance of AS; it is not merely sufficient for explaining the pattern of familial recurrence of the disease. This study's purpose is to investigate the association of ankylosing spondylitis with single-nucleotide polymorphisms (SNPs) in the IL-1 family: IL-1a (-889C/T) rs1800587, IL-1b (-511C/T) rs16944, IL-1b (+3962C/T) rs1143634, IL-1R (Pst-1 1970C/T) rs2234650 and IL-1RA (Mspa-1 11100C/T) rs315952. Methods. 99 unrelated Iranian AS patients and 217 healthy control subjects were selected. Cytokine typing was performed by the polymerase chain reaction with sequence-specific primers assay. The allele and genotype frequencies of the polymorphisms were determined: Results. The IL1 alpha rs1800587, IL1 beta rs16944 and IL1 beta rs1143634 were not significantly associated with AS. Genotype frequencies at IL1R rs2234650 differed between cases and controls (chi(2)=8.85; p=0.01); the IL1R rs2234650 C/T and T/T genotypes were less common in AS patients than controls. The IL1R rs2234650 C/T genotype was inversely associated with AS comparing with the IL1R rs2234650 C/C genotype (OR=0.48; p=0.005). IL1R rs2234650 C/T genotype was less common in patients than controls (OR=0.37; p=0.02). Furthermore IL1R rs2234650 T allele was strongly associated with HLA-B2702 patients rather than HLA-B2705 but was not associated with HLA-B27 negative patients (OR=0.33; p=0.01). Conclusion. Polymorphisms of IL1 alpha rs1800587, IL1 beta rs16944 and IL1 beta rs1143634 were not significantly associated with ankylosing spondylitis but inversely in this study IL1R rs2234650 was significantly associated and carriage of T allele in IL1R rs2234650 seems to be protective, while carriage of C allele result in two fold higher risk of developing AS.

• 出版日期2011-12