Combined pharmacogenetic effect of ADCY9 and ADRB2 gene polymorphisms on the bronchodilator response to inhaled combination therapy

P>What is known and objective: Inhaled combination therapy composing of long-acting beta 2-agonist and corticosteroid has been widely applied in the management of asthma, but observed treatment responses vary. The aim of this study was to evaluate the pharmacogenetic effect of the adenylyl cyclase type 9 (ADCY9) gene polymorphism on combination therapy. Materials and methods: Eighty-six mild to moderate Korean asthmatics were enrolled in this clinical trial. After the 2-week 'run-in' period, patients received budesonide (an inhaled corticosteroid) and formoterol (long-acting beta 2-agonist) during the following 12-week active treatment period. Forced expiratory volume in 1 s (FEV(1)) and maximum mid-expiratory flow (MMEF) levels were measured at all visits as primary outcome. ADCY9 (Ile772Met, 150127 C/T, 150130 C/T, 150397 C/T, 150479 C/T, TTTA (5/4)) and beta 2-adrenergic receptor (ADRB2, Arg16Gly) gene polymorphisms were genotyped. Results: Significant associations were observed between the ADCY9 single nucleotide polymorphisms and percent changes in FEV(1) (Ile772Met T/C, P = 0 center dot 030) and MMEF (150397 C/T, P = 0 center dot 016) after 8 weeks of combination therapy. Haplotype associations were also observed with respect to percent changes in FEV(1) after 8 weeks of therapy (Ht3[TTCC], P = 0 center dot 017). Additive therapeutic effect was observed in those with the ADCY9 Ile772Met and ADRB2 Arg16Gly gene polymorphisms in terms of percent change in FEV(1) after 8 and 12 weeks of therapy (P = 0 center dot 002 and P = 0 center dot 027 respectively). What is new and conclusion: Our results suggest that ADCY9 gene polymorphisms may alone, and in combination with ADRB2 gene polymorphisms, contribute to individual response to combination therapy in mild to moderate asthmatics.