Abstract
Background: Airway inflammation is a key component of asthma that depends on the interplay of multiple genes. Eosinophils and neutrophils have the ability to recognize distinct inflammatory phenotypes influencing the clinical characteristics of the disease.
Aim: To simultaneously assess the association among tag-SNPs located in 15 inflammation-related genes, EOS, NEU and lung function in adult asthma.
Methods: In Verona (Italy), 337 asthmatics (aged 20-64) were identified from the general population in the GEIRD study (2008/2010) and were classified into four inflammation groups: EOSlow (<3rd quartile = 260 EOS/mm3)/NEUlow (<3rd quartile = 5,050 NEU/mm3), EOSlow/NEUhigh, EOShigh/NEUlow, EOShigh/NEUhigh. SNPs were selected by testing their univariate association with the inflammation groups and pre-bronchodilator FEV1%pred under the additive genetic model (controlling the false discovery rate). The simultaneous relationships were evaluated by using a mediation model, with current smoking and the use of anti-asthmatic controller medications in the past three months as potential confounders.
Results: A SNP in the IL-18 gene region was selected for the mediation analysis. The mediation model is described in this figure:
Conclusions: This preliminary analysis suggests that a SNP in the IL-18 gene region is associated with the EOShigh/NEUhigh pattern, without a direct association with lung function.
- Copyright ©ERS 2015