Objective: To investigate the association between the promoter polymorphism -509C/T of the transforming growth factor-β1 gene (TGFB1) and the disease severity of allergic rhinitis (AR) in childhood.
Methods: A total of 96 Chinese patients with persistent AR aged 3 - 17 (9.4 ± 3.8) years old were enrolled in the study. Among these patients 53.1% were mild cases (n = 51) and 46.9% were 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 (χ(2) = 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: The results suggest that the TGFB1 gene polymorphism -509C/T may play a potential role in the severity of persistent AR in childhood.