A34-24 Air Trapping Without Emphysema: Presentations of COPD With Type II Inflammation in Bronchoscopic Lung Volume Reduction Referrals

Abstract Rationale Selection for Bronchoscopic Lung Volume Reduction (BLVR) is dependent on radiographic evidence of emphysema, typically assessed by high-resolution computed tomography (HRCT) and quantitative CT analysis, as well as on physiological evidence of air trapping and hyperinflation. BLVR with Endo-Bronchial Valve (EBV) relies on inducing atelectasis in emphysematous and hyperinflated lung regions, leading to improved lung mechanics and reduction in dyspnea. In the absence of radiographic emphysema, there is no target for BLVR and the patient is not considered a candidate. We hypothesize that patients with chronic obstructive pulmonary disease (COPD) who have severe air trapping but little to no emphysema on imaging may exhibit a distinct inflammatory profile with markers of Type II inflammation. Methods We studied a cohort of 19 patients who were referred to our BLVR program due to severe air-trapping on pulmonary function testing and were found not to be candidates due to insufficient emphysema on CT scan based on validated software for automated quantitative CT analysis such as StratX and Olympus. We cross-referenced the quantitative degree of emphysema with radiologist evaluations of emphysema. We then performed a chart review for markers of Type II inflammation. Results In our cohort, 7 patients had mild to no emphysema. These patients all had high eosinophil levels with a mean of 500 and a median of 300. Among this group, 3 of them also had high IgE levels of 36, 55, and 176. Only two of these patients were on a biologic at the time of evaluation. There were 6 patients in our cohort with a discrepancy in degree of emphysema between radiologist read and the quantitative CT analysis. These patients, who had moderate to severe levels of emphysema by radiology read, had a mean and median peripheral eosinophil count of 300 and 150, respectively. There were 6 patients excluded from the final analysis due to having a pulmonary disease other than COPD. Conclusions COPD patients referred for BLVR frequently exhibit air-trapping-dominant disease. Our data show that type II inflammation may be particularly enriched in these patients who are found to be ineligible for valves, regardless of their level of emphysema. This suggests an airway-predominant, Th2-high endotype that may respond to biologic therapies for COPD rather than valve-based interventions. Integrating inflammatory profiling into BLVR evaluation could enable precision triage toward anti-Type II biologic therapy. Prospective studies using advanced imaging and biologic response assessment are warranted. This abstract is funded by: None