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.

Patient-reported outcomes in moderate-to-severe allergic asthmatics treated with omalizumab: a systematic literature review of randomized controlled trials

“…The studies had a broad global representation, with 10 multi-national RCTs included [13][14][15][16][17][18][19][20][21][22] . The majority of included analyses evaluated patients aged 12 years and older (15 of 26 studies) [13][14][15][16][17][18]20,[22][23][24][25][26][27] ; five trials included adults, aged 18 years and older, only 21,[28][29][30][31] , and two trials included children aged 6 to <12 years 19,32 . The majority of RCTs were large (69% had n > 300 patients).…”

“…As shown in Table 4, adults with allergic asthma treated with omalizumab experienced improvements on the overall AQLQ score from baseline; the difference compared with placebo (and/or standard therapy for persistent severe asthma) was statistically significant in all but two studies 15,30 ; in these two studies, the change was numerically greater for omalizumabtreated patients, but statistical significance was not reported. 17,24 in the AQLQ scores of omalizumab-treated patients compared with placebotreated patients for the following: symptoms, activity limitation, and environmental exposure.…”

The Effect of Omalizumab on Eosinophilic Inflammation of the Respiratory Tract in Patients with Allergic Asthma

“…[36] noted inhibited production of TGF-b and pro-inflammatory cytokines (IL-4, IL-13 and TNF-a) by airway epithelial cells, stimulated by IL-1b and allergen. Hoshino et al [37] studied a clinical effect of omalizumab with regards to the remodelling process by using high-resolution CT (computed tomography) of the thoracic cavity. A follow-up examination performed after 16 weeks demonstrated thinner bronchial wall in patients with severe asthma, treated with omalizumab.…”

“…Their expression is increased by IL-4 and IL-13 [91]. Omalizumab has been found to affect the production of these cytokines [8,9,37], thus it can potentially also influence eosinophil diapedesis.…”

Severe Asthma: Anti-IgE or Anti-IL-5?

“…Recent studies have shown that long treatment with anti-IgE significantly reduced airway wall thickness and RBM thickness within 6 and 12 months, and this effect was independent of eosinophilic infiltration (21,22). Moreover, in another study, it was demonstrated that 48 weeks of treatment with omalizumab resulted in decrease in airway wall thickness as assessed by computed tomography (72).…”