Association of TRAF1-C5 with risk of uveitis in juvenile idiopathic arthritis

Abstract

Objectives: Numerous single nucleotide polymorphisms (SNPs) have been associated with JIA, but few of these studies were replicated. We conducted a candidate-gene approach study to assess if some SNPs could be related to clinical subtypes or other clinical features of the juvenile idiopathic arthritis (JIA) such as the risk of uveitis, ANA positivity and the age at onset.

Methods: SNPs in six genes were analysed: PTPN22, STAT4, TRAF1-C5, TGFbeta, TNFAIP3, and C12orf30. We retrospectively included 104 JIA patients, fulfilling the ILAR classification criteria. Association between SNPs and JIA clinical subtypes, the presence of ANA, risk of uveitis and age at onset was evaluated using a Chi² test or a Fischer test.

Results: No associations between different clinical subtypes as well as presence of ANA and the 6 SNPs were found. However, the AA genotype of TRAF1-C5 appeared associated in a subgroup of patients with uveitis in oligoarticular and polyarticular forms [OR 3.77 (95% CI: 1.1067, 12.8527); P=0.066]. Furthermore, AA TRAF1-C5 was significantly more frequent in antinuclear antibodies (ANA) positive patients presenting uveitis, compared to patients without uveitis and without ANA (P<0.05).

Conclusion: TRAF1-C5 genotype could identify JIA patients with a risk to develop uveitis especially in oligo and polyarticular forms and among ANA-positive children. Given the moderate size of our cohort, this association has to be confirmed in other studies.

Keywords: Antinuclear antibodies; ILAR classification; Juvenile idiopathic arthritis; Single nucleotide polymorphisms; TRAF1-C5; Uveitis.