Introduction
Response variability to treatment with inhaled corticosteroids (ICS) may be related to genetic variations among COPD patients. Various single-nucleotide polymorphisms (SNPs) have been identified in the glucocorticoid-induced transcript 1 (GLCCI1) gene and the related co-chaperone FKBP5 gene. The aim of our study was to investigate whether common variants of the aforementioned genes are associated with COPD phenotypes, lung function and ICS efficacy.
 
Methods
A total of 165 patients with COPD, GOLD stage B-D, subjects of the HISTORIC study, a randomized, placebo-controlled, double-blind, investigator-initiated trial aiming to examine the hypothesis that COPD patients with high airway smooth muscle cells (ASMC) in endobronchial biopsies respond better to corticosteroids that patients with low ASMC, were included in our study. The rs37973 polymorphism of the GLCCI1 gene and the rs4713916 polymorphism of the FKBP5 gene were analyzed by real-time PCR-TAQMAN SNP Genotyping Assay.
 
Results
COPD patients who responded better to triple therapy with long-acting beta 2 agonists (LABA), long-acting muscarinic antagonists (LAMA) and ICS presented with a higher prevalence of the A allele of the FKBP5 rs4713916 gene polymorphism (odds ratio=3.2, p=0.013). Patients who did not respond to triple therapy were found to be enriched in G allele (p=0.007). These patients also had a worse diffusion capacity (p=0.014).
 
Conclusion
The results of our study suggest a potential association of the FKBP5 gene polymorphism (rs4713916) with responsiveness to ICS in patients with COPD.