The phenotypic heterogeneity of obese and nonobese patients with severe asthma and comparison of omalizumab–mepolizumab treatment efficiency in these patients

In obese severe asthmatics, the degree of type 2 inflammation may vary according to their atopic status and past smoking history. In this study, we aimed to analyze the clinical and physiopathological features of obese and nonobese severe asthmatics treated with omalizumab or mepolizumab treatment. In addition we aimed to compare the clinical, spirometric outcomes and total peripheral eosinophilic count (TEC) changes after treatment with these 2 biologic agents in obese and nonobese groups. In this retrospective, cross sectional study, 121 severe asthmatic treated with biologic agents (omalizumab = 88 or mepolizumab = 33) for at least 16 weeks were included. Obese (n: 44) and nonobese severe asthmatics (n: 77) were analyzed according to whether they provided a ≥ 10 pack/years (p/y) or <10 p/y smoking history and were found to be atopic. Obese and nonobese groups were compared in terms of the change in the asthma control test, asthma attacks, TEC, and forced expiratory volume in the first second (FEV(1)) after treatment. In patients with ≥10 p/y smoking history, nonobese group had a significantly higher TEC compared to obese group [median (min–max) 660 cells/μL (200–1500) vs 300 cells/μL (110–770); p: 0.013]. Within the nonobese group, nonatopic patients had a significantly higher TEC compared to atopic patients [median (min–max) 1200 cells/μL (100–2100) vs 310 cells/μL (0–2730); p: 0.021]. Both biologic agents had similar effects on improving asthma control test and in reducing asthma attacks; however, mepolizumab was more effective in suppressing TEC. The improvement in FEV(1) in obese group following biologic 2 agents was very similar but in nonobese group, mepolizumab was found to be superior (510 mL vs. 295 mL; p: 0.034). In our real-life study, nonobese severe asthmatics with ≥10 p/y smoking history and those that were nonatopic had higher TEC. Compared to omalizumab, mepolizumab was superior at reducing TEC in all asthmatics and in improving FEV(1) in nonobese group.