Clustering of patients with bronchial asthma with regard to the genotypes for Bcl1 polymorphism in the glucocorticoid receptor gene

Abstract

The aim of study was to perform a cluster analysis in patients with adult-onset bronchial asthma (BA) with regard to ВсІ1 polymorphism in the glucocorticoid receptor gene. Materials and Methods: We examined 187 patients with persistent BA, diagnose in accordance with GINA recommendations, anthropometric, genetic and statistical methods of investigation were used. Results: The 1st cluster (n=69) consisted of women (71%), having partial or poor BA control, with normal weight, burdened allergological history; high blood levels of eosinophiles and IgE; decreased FEV1 (within 60 to 80%); long-term use of systemic glucocorticosteroids (SCS) and medium - high doses of ICS and LABA and with C/G genotype of ВсІ1 polymorphism in 68.1 % of patients. The 2nd cluster (n=31) included 67.7 % of women, 74.2% of subjects had obesity, normal level of eosinophiles; decreased FEV1 (within up to 60%); uncontrolled course, background therapy with ICS, LABA, SCS; frequent exacerbations and with G/G genotype of ВсІ1 polymorphism in 74.2% of patients. The 3rd cluster (n=87) predominantly contained men, having well-controlled or partially controlled BA; with no genetic factor; healthy weight; normal FEV1 and normal laboratory parameters; 36.8% of subjects having C/G and 40.3% – С/С genotype of ВсІ1 polymorphism. Conclusions: Cluster analysis of BA patients with regard to the genotypes of ВсІ1 polymorphism demonstrated 3 different BA subphenotypes that differed from each other in sex, BA course and control, values of respiratory function, BMI and inflammatory markers. These can contribute to individual approach to diagnostics and treatment of BA in the future.