Background: Asthma is a chronic respiratory disease caused by a combination of genetic and environmental factors. Transforming growth factor beta 1 (TGFB1) is a multifunctional cytokine that plays an important role in airway remodeling in asthma.
Objectives: The aim of this study was to analyze common TGFB1 gene promoter polymorphisms C-509T and G-800A in Serbian asthmatics and to investigate their association with exacerbations.
Material and methods: The study involved 102 asthmatics and 58 healthy individuals from Serbia, age and gender matched. An analysis of the TGFB1 promoter was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results: For polymorphism C-509T a significant difference in the allele frequency was observed between the patients and the controls (p = 0.011), while the genotype distribution was similar in the analyzed groups, with statistical significance near the borderline (p = 0.061). For the polymorphism G-800A no difference was observed between the groups. The frequency of the -509TT genotype was higher in patients with exacerbations compared to patients without exacerbations (36.4% vs. 17.0%), with statistical significance near the borderline (p = 0.080).
Conclusions: The results suggest that polymorphism C-509T may be associated with asthma and disease exacerbations, while G-800A is not significant for the etiology and clinical course of the disease. These findings should be confirmed in a larger study group, and since the TGFB1 promoter is highly complex and very responsive to environmental factors, future studies should also take other genetic and non-genetic factors into consideration.
Keywords: asthma; gene polymorphism; transforming growth factor beta 1.