Bronchoprotective tolerance with inhaled corticosteroid/long-acting β-agonist treatment

We read with interest the study by Cardet et  al,1 which showed that 38% of asthmatic patients receiving an inhaled corticosteroid (ICS) and a long-acting β-agonist (LABA; ie, fluticasone/salmeterol) experienced loss of bronchoprotection. We believe that their results need to be interpreted in light of the potential interaction between the L ABA moiety and the arginine/glycine genotype at position 16 (Arg16Gly) of the β2-adrenoceptor. For example, a post hoc genotype-stratified pooled analysis of 152 patients from randomized placebo-controlled trials showed that the degree of protection after chronic dosing with ICS/LABA treatment was 1.49 (95% CI, 0.5-2.48) doubling dose less in patients who possessed ArgArg or ArgGly genotypes (comprising about 60% of patients) compared with those who had the GlyGly genotype (about 40% of patients).
Source: Journal of Allergy and Clinical Immunology - Category: Allergy & Immunology Authors: Tags: Correspondence Source Type: research