Late Breaking Abstract - The impact of treatment with mepolizumab on airway remodeling in patients with severe eosinophilic asthma

Abstract

<b>Background:</b> Severe eosinophilic asthma involves chronic inflammatory process in the airways leading to changes in airway structure, known as airway remodeling. IL-5 is a central cytokine promoting eosinophil activation and a primary target for biological agents such as mepolizumab. However, the influence of mepolizumab on airway remodeling is unclear. <b>Aims and objectives:</b> To assess the impact of mepolizumab therapy on airway remodeling traits estimated by chest high-resolution computed tomography (HRCT) and endobronchial ultrasound (EBUS) in severe eosinophilic asthma. <b>Methods:</b> In 15 severe eosinophilic asthma patients HRCT and EBUS were performed before and after 1 year of treatment with mepolizumab. The 10th right segment bronchus was chosen for HRCT analysis, including measurements of bronchial wall area (WA), percentage of wall area (WA%), ratio between luminal area and total area (Ai/Ao). In EBUS mean thickness of bronchial wall and its inner layers (L1, L2, L3) were evaluated. <b>Results:</b> Treatment with mepolizumab resulted in significant reduction in bronchial wall thickness (1.3±0.08mm vs 1.26±0.07mm, p&lt;0.001) and its layers: L1 (0.186±0.01mm vs 0.178±0.008mm, p&lt;0.001), L2 (0.2±0.01mm vs 0.19±0.015mm, p=0.003) and L3 (0.915±0.064mm vs 0.88±0.06mm, p&lt;0.001) in EBUS. In HRCT, decrease of WA% (70.08±7.93% vs 62.27±3.88%, p&lt;0.001) and increase of Ai/Ao (0.29±0.07 vs 0.38±0.037, p&lt;0.001) was significant only among patients with longer asthma duration and lower baseline FEV1 (n= 7). <b>Conclusions:</b> One year of treatment with mepolizumab substantially improved airway remodeling parameters in studied group. That effect was better noticeable in invasive EBUS than in non-invasive HRCT.