Association of CYP3A5 (6986A>G) gene polymorphism with the effectiveness of anti-inflammatory therapy in children with bronchial asthma

Inhaled glucocorticosteroids are the main drugs used to control bronchial asthma in children. P450-cytochrome of  3A (CYP3A) family is involved in  their metabolism. CYP3A5-isoenzyme plays the leading role in  the respiratory tract. We described 6986A>G polymorphism in the CYP3A5 gene encoding this isoenzyme.Aim of the study. To evaluate the association of CYP3A5 (6986A> G) gene polymorphism with the effectiveness of drugs in children with bronchial asthma.Materials and methods. We examined 108 children from 6 to 17 years with bronchial asthma. The allergist carried out the dynamic outpatient polyclinic follow-up of patients, assessed the symptoms of the disease and corrected the corresponding basic therapy. All children underwent genotyping for the 6986A> G polymorphic marker of the CYP3A5 gene.Results. Ten (9.26%) children were heterozygous for the 6986A> G polymorphic marker of  the CYP3A5 gene (AG genotype). The authors obtained statistically significant differences in the frequency of the AG genotype between the patients receiving control therapy for bronchial asthma of the 1st – 2nd stage and the patients with control therapy of the 3rd and higher stages in accordance with GINA criteria (p=0.031). In the group with severe bronchial asthma, the number of heterozygotes for the 6986A> G polymorphic marker of the CYP3A5 gene was significantly higher than among children with a mild course of the disease (p=0.029).Conclusion. The AG genotype and A-allele (CYP3A5 gene, A6986A> G polymorphism) are associated with the need for greater volume of control therapy for bronchial asthma and they are risk factors of a more severe course of the disease.