Effects of Adding Omalizumab, an Anti-Immunoglobulin E Antibody, on Airway Wall Thickening in Asthma

Abstract

Background: Omalizumab may inhibit allergic inflammation and could contribute to decreasing airway remodeling in patients with asthma. Objective: The aim of this study was to assess the effects of omalizumab on airway wall thickness using computed tomography (CT). Methods: Thirty patients with severe persistent asthma were randomized to conventional therapy with (n = 14) or without omalizumab (n = 16) for 16 weeks. The following airway dimensions were assessed by a validated CT technique: airway wall area corrected for body surface area (WA/BSA), percentage wall area (WA%), wall thickness (T)/√BSA, and luminal area (Ai)/BSA at the right apical segmental bronchus. The percentage of eosinophils in induced sputum, pulmonary function and the Asthma Quality of Life Questionnaire (AQLQ) were assessed as well. Results: Treatment with omalizumab significantly decreased WA/BSA (p < 0.01), WA% (p < 0.01), and T/√BSA (p < 0.01), and increased Ai/BSA (p < 0.05), whereas conventional therapy resulted in no change. In the omalizumab group (n = 14), a significant decrease in the percentage of sputum eosinophils (p < 0.01), improved forced expiratory volume in 1 s (FEV₁), and an improved AQLQ score were recorded. The changes in FEV₁% predicted and sputum eosinophils were significantly correlated with changes in WA% (r = 0.88, p < 0.001, and r = 072, p < 0.01, respectively). Conclusions: These findings suggest that omalizumab reduced airway wall thickness and airway inflammation. Larger patient studies with longer-term follow-up are needed to show whether omalizumab can truly maintain improved airway wall dimensions.