Association of interleukin 1beta and receptor antagonist gene polymorphisms with primary open-angle glaucoma

Purpose: Genetic factors are known to play a role in the etiology of glaucoma. More specifically, the role of the immune system is highly suspected. We evaluated the association between 2 polymorphisms in the interleukin (IL) 1beta gene (IL-1 promoter 511, IL-1 exon 5) and 1 polymorphism in the IL-1 gene receptor antagonist (IL-1Ra) intron 2 with primary open-angle glaucoma (POAG).

Patients and methods: Fifty-eight POAG patients and 105 healthy volunteers were enrolled in this study. Analysis based on polymerase chain reaction was used to resolve the 2 IL-1beta polymorphisms and the IL-1Ra intron 2 polymorphism.

Results: There were significant differences in the distribution of the IL-1beta exon 5 polymorphism between the POAG patients and the control subjects (p < 0.05). The E2 allele of IL-1beta exon 5 was more frequently found in POAG patients than in healthy patients (odds ratio: 4.224, 95% confidence interval = 1.135-15.717). The distributions of the other 2 polymorphisms, IL-1beta promoter 511 and IL-1Ra intron 2, were not significantly different between the POAG patients and the healthy control group.

Conclusions: The frequency of the E2 allele of the IL-1beta exon 5 polymorphism was high in POAG patients. Therefore the E2 allele can be used as a marker to predict or search for the genetic causes of glaucoma in Chinese POAG patients. Furthermore, we have concluded that the other 2 polymorphisms (IL-1 promoter 511 and IL-1Ra) are not helpful in predicting Chinese POAG.