Interleukin-1 gene polymorphisms in axial spondyloarthritis Tunisian patients.

Axial spondyloarthritis (SpA) is a common inflammatory arthritis characterized by axial skeletal inflammation, enthesitis, and association with HLA-B27. Pro-inflammatory cytokines play important roles in the regulation of inflammatory response and seem to be good candidates involved in the development of this pathology. To assess the influence of the functional polymorphisms of single nucleotide polymorphims (SNPs) of IL-1 and IL-1 Ra in SpA susceptibility Tunisian patients. One hundred and one patients and 100 ethnic-matched healthy controls were genotyped. Susceptibility to SpA was showed with SNP's: C/T of IL-1α (-889) (p=0.0001) and 1/1 of IL-1Ra (p<10-3). Analysis of SpA patients according to clinical behavior of the disease reveled the influence of these polymorphisms in SpA course. Indeed, individuals carrying the allele T (+3954) of IL-1β and allele 1 of IL-1Ra had an increased risk of peripheral arthritis (p=0.047, p=0.05, respectively). Also the 1/1 genotype of IL-1Ra was significantly decreased in SpA patients having an active disease (BASDAI>4) (p=0.033). Genetic polymorphisms of pro-inflammatory IL-1/IL-1Ra cytokines seem to be involved in susceptibility and clinical course of SpA in Tunisian patients.