The association between interleukin 1 beta promoter polymorphisms and keratoconus incidence and severity in an Egyptian population

Abstract

Purpose: In the present study, we investigated whether interleukin 1 beta (IL1B) promoter polymorphisms are associated with keratoconus in an Egyptian population and their association with disease severity. Methods: A total of 95 Egyptian keratoconus patients and 126 Egyptian healthy controls were enrolled in the study. Two IL1B single nucleotide polymorphisms (SNPs) (rs1143627 and rs16944) were genotyped using Taqman real-time PCR to compare haplotype, genotype, and allele frequencies between cases and controls (primary outcome) and their association with disease severity (secondary outcome). Results: Statistically significant association was observed for rs1143627 and rs16944; the T allele of rs1143627 and the G allele of rs16944 were associated with an increased risk of keratoconus (p < 0.001, odds ratio = 3.313, 4.770, respectively). The TT genotype of rs1143627 and the GG genotype of rs16944 were strongly associated with an increased risk of keratoconus (p < 0.001, odds ratio = 5.631, 11.478, respectively). The G allele of rs16944 was associated with an increased curvature of the flattest corneal meridian Kf in keratoconus (p = 0.041). The GG genotype of rs16944 was associated with an increased curvature of the flattest corneal meridian Kf, steepest corneal meridian Ks and average corneal curvature Kavg in keratoconus (p = 0.01, 0.046, 0.023, respectively). Conclusion: IL1B is suspected to play a crucial role, both in development and severity of keratoconus in Egyptian population.