Association Of Tgfb1 Gene Polymorphism －509C/T With Disease Severity In Childhood Allergic Rhinitis

Background: Transforming growth factorβ1 (TGF-β1) is an important fibrogenic and immunomodulatory factor considered to have pivotal roles in the pathogenesis of airway remodeling. Increasing evidence has demonstrated that the promoter polymorphism -509C/T of the TGF-β1 gene (TGFB1) may modulate asthma occurrence in childhood. Allergic rhinitis (AR) is a symptomatic disorder of the nose induced after allergen exposure by an IgE-mediated inflammation of the membranes lining the nose. Pediatric AR represents a global health problem with increasing prevalence over the last decades. AR and asthma are conditions of airway inflammation that often coexist. They have closely related phenotypes and may share the common genetic background. However, few attention was focus on the association between the TGFB1 promoter polymorphism -509C/T and AR in childhood.Objective: To investigate the association between the TGFB1 promoter polymorphism -509C/T and the disease severity of AR in childhood.Methods: A total of 96 Chinese patients with persistent AR aged 3-17 (9.4±3.8) years were enrolled in the study. The patients included 53.1% of mild cases (n=51) and 46.9% of moderate-to-severe cases (n=45). Genotyping was performed on peripheral blood genomic DNA by using PCR-RFLP. Serum levels of TGF-β1 was measured by ELISA, and serum total IgE, specific IgE and eosinophil cationic protein (ECP) levels were determined using an ImmunoCAP100E system. Statistical analysis was conducted with SPSS11.0 software. Results: Significant differences were found in genotype frequencies for the TGFB1-509C/T polymorphism between mild and moderate-to-severe AR patients (χ2=8.361, P=0.015). Children with persistent AR bearing the TT genotype of the-509C/T polymorphism had significantly increased risk for moderate-to-severe AR (Fisher's exact test, P=0.007) compared to children with the CC/CT genotypes. There was no significant association between the-509C/T polymorphism and serum TGF-β1 levels (F=0.389, P=0.679); however, serum total IgE (F=4.210, P=0.018) and ECP (H=6.297, P=0.043) levels were found to be significantly associated with the polymorphism.Conclusion: Our results suggest that the TGFB1 gene polymorphism-509C/T may play a potential role in the severity of persistent AR in childhood.