Age-Related Changes of Transforming Growth Factor β1 in Japanese Children

Transforming growth factor β1 (TGFβ1) is an important factor in immunomodulation. The expression of TGFβ1 has been shown to be influenced by the C-509T polymorphism in the TGFβ1 gene. We investigated age-related changes of plasma TGFβ1 levels in a birth-cohort study. In addition, the genotypes of the C-509T polymorphism were investigated in allergic and non-allergic subjects. Sixty-four neonates who met the following criteria were enrolled in this cohort study: 1) full-term vaginally delivery; 2) underwent DNA polymorphism analysis; and 3) questionnaire forms were filled out by parents at 0, 6 and 14 months of age. The umbilical cord blood at 0 months and peripheral blood at 6, and 14 months were collected. Plasma TGFβ1 levels were measured at 0, 6 and 14 months of age. Genomic DNA was extracted from their umbilical cord blood. The genotype of the subjects was examined for the presence of C- 509T. The plasma TGFβ1 level at 6 months was the highest of the 3 measurements (at 0, 6, and 14 months of age). The TGFβ1 levels at 14 months in allergic subjects were significantly higher than those in non-allergic subjects (p = 0.03). All subjects with bronchial asthma (n = 3) had the TT genotype of the C-509T polymorphism. The plasma TGFβ1 levels change with age. In addition, TGFβ1 may play a role in the pathogenesis of bronchial asthma.