GLCCI1 rs37973: A potential genetic predictor of therapeutic response to inhaled corticosteroids in Chinese asthma patients

Glucocorticoids are the primary anti-inflammatory therapy for asthma, but their effects are characterized by some interindividual variability that might have a genetic basis.We aimed to determine the relationship between pulmonary function change and the variant of the glucocorticoid-induced transcript 1 (GLCCI1) gene in patients with asthma receiving long-term ICS treatment, the association of GLCCI1 genotypes and the level of GLCCI1 expression and cytokines production.A total of 418 patients with asthma, including 25 individuals from 11 families with a history of asthma, were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1 on changes in lung function in response to inhaled glucocorticoids were assessed. The expression levels of GLCCI1 mRNA and cytokines were also measured.The SNP rs37973 in GLCCI1 was independently associated with changes in forced expiratory volume at one second (FEV1) and FEV1%pred. Individuals homozygous for the wild-type allele who had a percent FEV1 change greater than 5% were more common than individuals homozygous for the rare allele. When patients were stratified according to genotype, GLCCI1 expression was enhanced upon administration of low-dose dexamethasone among patients with the rs37973 A allele; however, GG homozygotes required high-dose dexamethasone to achieve enhanced GLCCI1 expression. Furthermore, the levels of some cytokines were significantly reduced after glucocorticoid treatment in individuals with the AA and AG genotypes.The genetic variant rs37973 in GLCCI1 is associated with poorer clinical therapeutic response to inhaled glucocorticoids in a Chinese asthma population.

GLCCI1 variant accelerates pulmonary function decline in patients with asthma receiving inhaled corticosteroids

BACKGROUND

In steroid-naive patients with asthma, several gene variants are associated with a short-term response to inhaled corticosteroid (ICS) treatment; this has mostly been observed in Caucasians. However, not many studies have been conducted for other ethnicities. Here, we aimed to determine the relationship between the annual decline in forced expiratory flow volume in one second (FEV1 ) and the variant of the glucocorticoid-induced transcript 1 gene (GLCCI1) in Japanese patients with asthma receiving long-term ICS treatment, taking into account the effect of high serum periostin levels, a known association factor of pulmonary function decline and a marker of refractory eosinophilic/Th2 inflammation.

METHODS

In this study, 224 patients with asthma receiving ICS treatment for at least 4 years were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1, stress-induced phosphoprotein 1 (STIP1), and T gene on the decline in FEV1 of 30 ml/year or greater were determined.

RESULTS

Besides the known contributing factors, that is, the most intensive treatment step, ex-smoking, and high serum periostin levels (≥95 ng/ml), the GG genotype of GLCCI1 rs37973, and not other SNPs, was independently associated with a decline in FEV1 of 30 ml/year or greater. When patients were stratified according to their serum periostin levels, the GG genotype of rs37973 was significantly associated with blood eosinophilia (≥250/μl) in the high serum periostin group.

CONCLUSIONS

A GLCCI1 variant is a risk factor of pulmonary function decline in Japanese patients with asthma receiving long-term ICS treatment. Thus, GLCCI1 may be associated with response to ICS across ethnicities.