Objective: Multiple studies indicate the role of the IL-17/IL-23 axis in autoimmune diseases including systemic sclerosis (SSc). The aim of the current study was to investigate the possible implication of the IL23R gene in SSc susceptibility and/or clinical phenotype.
Methods: An initial case-control study in 143 Dutch SSc patients and geographically matched healthy individuals (n = 246) was carried out and followed by a replication study in a cohort of 365 Spanish SSc patients and 515 healthy individuals. Seven single nucleotide polymorphisms (SNPs) spanning the IL23R gene were selected and genotyped using a Taqman assay.
Results: Using a Dutch cohort of SSc patients and controls we observed an association between two (rs11209032, rs1495965) of the seven tested SNPs and disease susceptibility (allelic p values: P=0.02 and P=0.01 respectively). However, a replication study in an independent Spanish cohort did not confirm these findings and reveal no association of any of the IL23R tested SNP with disease susceptibility or clinical phenotype. Similarly, a meta-analysis considering both populations did not reveal any significant association. In addition, no association was observed between IL23R genetic variants and SSc clinical phenotypes.
Conclusions: Our results suggest that the IL23R gene is not associated with SSc susceptibility or clinical phenotype.