Polymorphism –509C/T in TGFB1 Promoter Is Associated With Increased Risk and Severity of Persistent Allergic Rhinitis in a Chinese Population

Abstract

Background Polymorphism –509C/T in the promoter of transforming growth factor beta1 ( TGFB1) gene is implicated in the pathogenesis of asthma. This polymorphism might also act to regulate the development of allergic rhinitis (AR). Objectives To investigate whether –509C/T is associated with AR susceptibility and severity in a Han Chinese population. Methods The study enrolled 263 patients with persistent AR and 249 healthy controls. AR patients were classified as mild or moderate/severe AR groups according to the Allergic Rhinitis and its Impact on Asthma classification. TGFB1 gene polymorphism –509C/T was genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum total Immunoglobulin E (IgE) and specific IgE levels were determined using an ImmunoCAP. Results Significant difference was found in the allele frequency of TGFB1 –509C/T between AR patients and healthy controls ( P = .027) but not in the genotype frequency ( P =.051). However, the genotype frequency of TGFB1 –509C/T showed significant difference between the mild AR group, the moderate/severe AR group, and the control group ( P = .012); between the moderate/severe AR group and the control group ( P =.036); between the mild AR group and the moderate/severe AR group ( P = .038); but not between the mild AR group and the control group ( P =.075). Conclusion TGFB1 promoter polymorphism –509C/T may be associated with the susceptibility and the severity of persistent AR of Han Chinese, but the functional relationship still needs clarification.