Effects of adding omalizumab, an anti-immunoglobulin E antibody, on airway wall thickening in asthma.

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 (FEV(1)), and an improved AQLQ score were recorded. The changes in FEV(1)% 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.