Linking COPD Severity With Emphysema Phenotypes Identified Via CT

Panlobular emphysema (PLE) is associated with more chronic obstructive pulmonary disease (COPD) symptom burden, greater airflow obstruction, greater extent of emphysema, and higher systemic inflammation, according to a study published in Respiratory Medicine.

Understanding phenotypic patterns in COPD and associating them with clinical course and outcomes of the disease can help to guide therapy for clinicians and predict prognosis. Chest computed tomography (CT) has become routine in clinical research on COPD, and recent studies show an association of CT data with treatable traits. In the current study, researchers aimed to describe CT findings in 83 patients with COPD to better understand emphysema phenotypes and determine associations with clinical parameters including lung function, inflammatory markers, and quality of life. An expert radiologist reviewed historic chest CT scans and scored them for emphysema subtype, extent, and distribution.

The researchers found that 84% of participants had radiographic emphysema and of those, 26% had panlobular emphysema (PLE), 68% had centrilobular emphysema (CLE), and 6% had paraseptal emphysema (PSE). Compared with participants with no radiographic emphysema, the presence of PLE-dominant emphysema was associated with a lower BMI (P=.012) and a greater extent of emphysema (P =.014). In addition, after adjusting for age, sex, and pack-years smoking history, the researchers found that PLE was associated with greater airflow obstruction by FEV1% (forced expiratory volume in 1 second divided by vital capacity times 100) (48% vs 71%, P =.005), greater symptom burden by COPD Assessment Test (CAT) score (18 vs 9, P =.015), worse quality of life by the St. George’s Respiratory questionnaire (SGRQ) score (43 vs 22, P =.025), and more systemic inflammation by erythrocyte sedimentation rate (P =.001). The researchers also found that CLE and PSE were not similarly associated with these clinical features or symptom burden.

The authors concluded, “Further investigation is indicated to explore the pathogenesis of the PLE phenotype and the prognostic and treatment implications of PLE.”

Disclosure: This research was supported by an investigator-initiated grant awarded to one of the study authors from Amgen, Inc. Please see the original reference for a full list of disclosures.

Reference

Wilgus ML, Abtin F, Markovic D, et al. Panlobular emphysema is associated with COPD disease severity: a study of emphysema subtype by computed tomography. Respir Med. Published online December 13, 2021. doi:10.1016/j.rmed.2021.106717