Polymorphisms of Beta2-Adrenergic Receptor Gene in Serbian Asthmatic Adults: Effects on Response to Beta-Agonists

Abstract

Background and Objectives Polymorphisms of beta2-adrenergic receptor gene (ADRB2) are clinically relevant for several reasons, including as a risk factor for asthma development/severity and predicting the effectiveness of treatment with beta2-agonists in reducing asthma symptoms. The aim of this study was to examine the association between ADRB2 gene polymorphisms and asthma in the Serbian population, and to evaluate the therapeutic response in relation to the ADRB2 genotype. Methods The study included 171 patients with asthma and 101 healthy subjects as the control group. Genotyping of Arg16Gly and Gln27Glu polymorphisms was performed by direct sequencing of polymerase chain reaction (PCR) products. Results In Serbian adults, carriers of the 27Gln allele and 27Gln/Gln genotype were at higher risk of asthma [odds ratio (OR) 2.5, 95 % confidence interval (CI) 1.6-3.8, and OR 3.00, 95 % CI 1.7-5.3, respectively], while the presence of the 27Glu allele and 27Gln/Glu genotype were found to be protective of asthma (OR 0.4, 95 % CI 0.3-0.6, and OR 0.3, 95 % CI 0.1-0.7, respectively). Furthermore, we found that the presence of the 27Gln allele in asthmatics younger than 50 years leads to a better response to therapy with long-acting beta2-agonists (LABA) in combination with prevailing low and moderate doses of inhaled corticosteroids (ICS), while carriers of the 27Glu allele over 50 years old are more likely to respond to LABA + ICS therapy. Conclusion We identified that in Serbian adults the 27Gln allele and 27Gln homozygosity are risk factors for asthma, which may be of clinical interest in disease prevention. The finding that younger carriers of the 27Gln allele respond better to LABA + ICS therapy may be utilized in personalized asthma treatment.