Search

This study was undertaken to investigate the possible genetic association of functional CTLA4 polymorphisms with susceptibility to non-anterior uveitis. Four hundred and seventeen patients with endogenous non-anterior uveitis and 1517 healthy controls of Spanish Caucasian origin were genotyped for the CTLA4 polymorphisms rs733618, rs5742909 and rs231775, using predesigned TaqMan(©) allele discrimination assays. PLINK software was used for the statistical analyses. No significant associations between the CTLA4 polymorphisms and susceptibility to global non-anterior uveitis were found. It was also the case when the potential association of these genetic variants with the anatomical localization of the disease, such as intermediate, posterior or panuveitis, was assessed. Our results do not support a relevant role of these CTLA4 polymorphisms in the non-anterior uveitis genetic predisposition.

BACKGROUND: Large-scale genetic studies have reported several loci associated with specific disorders involving uveitis. Our aim was to identify genetic risk factors that might predispose to uveitis per se, independent of the clinical diagnosis, by performing a dense genotyping of immune-related loci.METHODS: 613 cases and 3693 unaffected controls from three European case/control sets were genotyped using the Immunochip array. Only patients with non-infectious non-anterior uveitis and without systemic features were selected. To perform a more comprehensive analysis of the human leucocyte antigen (HLA) region, SNPs, classical alleles and polymorphic amino acid variants were obtained via imputation. A meta-analysis combining the three case/control sets was conducted by the inverse variance method.RESULTS: The highest peak belonged to the HLA region. A more detailed analysis of this signal evidenced a strong association between the classical allele HLA-A*2902 and birdshot chorioretinopathy (p=3.21E-35, OR=50.95). An omnibus test yielded HLA-A 62 and 63 as relevant amino acid positions for this disease. In patients with intermediate and posterior uveitis, the strongest associations belonged to the rs7197 polymorphism, within HLA-DRA (p=2.07E-11, OR=1.99), and the HLA-DR15 haplotype (DRB1*1501: p=1.16E-10, OR=2.08; DQA1*0102: p=4.37E-09, OR=1.77; DQB1*0602: p=7.26E-10, OR=2.02). Outside the HLA region, the MAP4K4/IL1R2 locus reached statistical significance (rs7608679: p=8.38E-07, OR=1.42). Suggestive associations were found at five other loci.CONCLUSIONS: We have further interrogated the association between the HLA region and non-infectious non-anterior uveitis. In addition, we have identified a new non-HLA susceptibility factor and proposed additional risk loci with putative roles in this complex condition.