TGFB1 promoter polymorphism C-509T and pathophysiology of asthma

In addition to increased serum TGF-β1 levels, the T allele of the C-509T polymorphism is related to increased airflow obstruction but attenuated eosinophilic inflammation. The former relation is not attributed to thickening of the central airway walls. The latter relation might reflect the anti-inflammatory effect of TGF-β1. The C-509T polymorphism has a complex role in asthma pathophysiology, presumably because of the diverse functions of TGF-β1 and its various interactions with cells and humoral factors in vivo.