Obese Asthmatics are Characterised by Altered Adipose Tissue Macrophage Activation

This study aimed to quantify and immuno‐phenotype adipose tissue macrophages (ATMs) from obese asthmatics and obese non‐asthmatics, and to examine associations between adipose tissue, systemic and airway inflammation. Visceral (VAT) and sub‐cutaneous (SAT) adipose tissue were collected from obese adults undergoing bariatric surgery and processed to obtain the stromovascular fraction. Pro‐ (M1) and anti‐inflammatory (M2) macrophages were quantified by flow cytometry. Cytospins of induced sputum were stained for differential cell counts. Plasma C reactive protein (CRP) and CD163 were measured by ELISA. VAT contained a higher number of ATMs compared to SAT. A higher percentage of M1 ATMs was observed in VAT of obese asthmatics compared to obese non‐asthmatics. The M1:M2 ratio in VAT was negatively associated with FEV1%. Sputum macrophage count was correlated positively with M1 ATMs and negatively with M2 ATMs in VAT. In obese asthmatics, CRP was positively associated with M1:M2 ratio in VAT. There were no associations with CD163. An elevated ratio of M1:M2 ATMs was observed in VAT of obese asthmatics with increased disease severity. VAT inflammation with increased pro‐inflammatory macrophages (M1) occurs in obese asthma and may be a determinant of systemic inflammation and asthma severity. This article is protected by copyright. All rights reserved.
Source: Clinical and Experimental Allergy - Category: Allergy & Immunology Authors: Tags: Original Article ‐Asthma and Rhinitis Source Type: research