IL2RA gene polymorphism rs2104286 A>G seen in multiple sclerosis is associated with intermediate uveitis: possible parallel pathways?

PURPOSE: Uveitis is a major cause for visual impairment. Inflammation-related gene polymorphisms have previously been shown to confer susceptibility to different types of uveitis. Recently, IL-2 receptor alpha (IL2RA, also called CD25) and IL-7 receptor alpha (IL7RA) gene variants (rs2104286, rs12722489, and rs6897932) have been identified to play an essential role in the pathogenesis of immune-mediated diseases. Their role in uveitis, however, has not yet been studied. The present study was set to investigate a hypothesized association of these gene polymorphisms and the presence of either intermediate or HLA-B27-associated acute anterior uveitis.

METHODS: One hundred forty-five patients with HLA-B27-associated acute anterior uveitis (AAU), 84 patients with intermediate uveitis, 132 HLA-B27-negative controls, and 61 HLA-B27-positive controls were enrolled. Determination of genotypes was done by polymerase chain reaction.

RESULTS: The frequency of carriers of the minor allele for rs2104286 was significantly lower in patients with intermediate uveitis compared with HLA-B27 positive and negative controls combined (P = 0.006). Frequencies of the minor allele for rs2104286 did not differ significantly in patients with HLA-B27-associated uveitis (28.3%) when compared with HLA-B27-negative controls (24.2%; P = 0.29) and HLA-B27-positive controls (30.3%; P = 0.72). The rs12722489 and rs6897932 polymorphisms were not significantly associated with either investigated uveitis entity (P > 0.005).

CONCLUSIONS: These findings suggest an association of the rs2104286 polymorphism with intermediate uveitis, but not with HLA-B27-associated acute anterior uveitis. Because this polymorphism was associated with multiple sclerosis in previous studies, the authors suggest possible parallel pathways between multiple sclerosis and intermediate uveitis but not HLA-B27-associated uveitis.