Increased prevalence of interleukin-1 receptor antagonist gene polymorphism in patients with chronic rhinosinusitis

Objective: To assess the association of the interleukin (IL)-1 beta and the IL-1 receptor antagonist (IL-1Ra) gene polymorphisms with chronic rhinosinusitis (CRS). Design: Genotyping of the 2 IL-1 beta-gene (IL1B) polymorphisms (promoter and exon) and the IL-1Ra gene (IL1RN) polymorphism (intron 2) was performed using polymerase chain reaction and restriction length fragment polymorphism analyses. Setting: Prospective study, tertiary medical center. Patients: The study population comprised 88 consecutive adult Taiwan-Chinese patients who met stringent criteria for CRS and received endoscopic sinus surgery and 103 healthy volunteers of the same ethnicity and similar age range. Of the 88 patients, 61 had CRS with nasal polyps, while the other 27 had CRS without nasal polyps. Results: There were significant differences in the distribution of the IL1RN polymorphism between the control subjects and patients with CRS (P < .05). The II allele of IL1RN occurred more frequently in the CRS patient group, and the odds ratio for subjects with I/II genotype was 3.39 (95% confidence interval, 1.25-9.18). In the case of CRS without nasal polyps, the odds ratio for subjects with I/II genotype was further increased to 4.75 (1.39-16.25). There was no association between the other 2 polymorphisms of IL1B and CRS. Conclusion: Increased prevalence of IL1RN polymorphism in patients with CRS suggests that this polymorphism, or a polymorphism in linkage disequilibrium with it, may be involved in the development of CRS.