Inflammation-related genes, peripheral blood eosinophil (EOS) and neutrophil (NEU) count, and lung function in adult asthma

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 (u003c3rd quartile = 260 EOS/mm3)/NEUlow (u003c3rd 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: ![Figure][1] 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. [1]: pending:yes