Is there an endotype to the treatable eosinophilic trait of chronic obstructive pulmonary disease (COPD)

Abstract

Introduction: There has been much interest in defining phenotypes in COPD particularly in relation to eosinophils and whether it is a treatable trait. Augusti el al (1) have suggested defining an endotype of COPD and moving away from clinical measures, when it comes to offering treatment. An endotype in eosinophilic COPD remains to be explored. Our main aim was to define an endotype for the treatable eosinophilic trait of COPD particularly focusing on the Body Mass Index (BMI), as previous reports have shown this trait may have a BMI≥25 kg/m2(2).

Methods and Aims: A retrospective analysis was done reviewing the results of all COPD patients with an FEV1: FVC ratio <0.7, discussed at the local Multi-disciplinary Team meeting in 2019 and 2020. We excluded patients with Asthma and Overlap syndrome. Serum eosinophil levels over the past 3 years and BMI were obtained from the local electronic portal and MDT pro forma. We compared highest 3 year eosinophil counts (EC) in those with BMI < and ≥25 kg/m2. We used MS Excel and Vassar stats for statistical calculations.

Results: 168 patients were reviewed of which 24 patients were excluded based on the inclusion criteria, leaving 144 patients for analysis. The mean age (SD) was 57 (6.8) years. 58% (n= 84) were males. 39% (n=56) patients had BMI<25 kg/m2 (Group A) and 61% (n=88) patients had BMI≥25 kg/m2 (Group B). Mean (SD) of EC was 0.16x109/L (0.08) in Group A v Mean (SD) of EC 0.34 x109/L (0.14) in Group B [95% CI 0.14-0.21; p < 0.0001].

Our data show that patients with a BMI≥25 kg/m2 is an endotype of COPD patients who have EC>0.2 x109/L. Further research into this endotype and targeted treatments for eosinophilic COPD needs to be carried out.