Blood neutrophil pattern is associated with poor asthma control in adults from the EGEA study

Abstract

Introduction: Blood neutrophilia and eosinophilia are features of asthma. Data are limited on their stability over time and how they are associated with asthma control in adults. Aim: To study whether and how blood inflammatory patterns were associated with asthma symptom control and exacerbations. Methods: Analyses were conducted in 474 adults with asthma (38.2 yrs, 48% women) participating in the 2nd survey of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA2), including 242 adults followed-up from the 1rst survey (EGEA1). At EGEA2, asthma symptom control was assessed in 3 classes (GINA 2014) and exacerbations by use of urgent care or oral corticosteroids in the last year. Four blood inflammatory patterns were defined at EGEA 1 and 2: Results: At EGEA2, both NEUhi and EOShi patterns were associated with poor asthma control (OR[95%CI]=2.94[1.85-4.67] and 1.61[1.11-2.34] respectively). NEUhi pattern was also associated with exacerbations (2.61[1.48-4.63]), and EOShi pattern with poor lung function (FEV1: 93.2 vs. 97.3 % pred., p=0.02). NEUhi and EOShi patterns were stable over time in almost 50% of the 242 adults. Persistent NEUhi (at EGEA1 and 2) was associated with poor asthma control at EGEA2 (3.09[1.18-7.05]), whereas NEUhi at EGEA1 was not. Both EOShi at EGEA1 and persistent EOShi were associated with poor lung function at EGEA2 (FEV1: 90.5 vs. 95.3%, and 88.6 vs. 96.0 % pred., p=0.05). Conclusion: Blood inflammatory patterns were differently associated with asthma control in adults, suggesting specific role for each one.