Airway luminal area in long COVID patients compared to acute COVID-19 patients

Abstract

Background: Patients with respiratory manifestations of acute COVID-19 infection have enlarged luminal areas of central conducting airways demonstrated on computed tomography imaging and abnormal pulmonary function. In some cases, COVID-19 symptoms may persist for more than 4 weeks, referred to as long COVID, and the effect on airway luminal area remains unknown. Herein, we report airway luminal cross-sections areas among a long COVID group, compared to individuals with an acute COVID-19. We aim to investigate if large conducting airways sizes are different between acute COVID-19 and long COVID patients. Methods: A cohort of 181 people with long COVID were screened, of which 20 people (9 men, 11 women; 55.9 ± 14.1 years) were included in analyses. Twenty age, height, and sex matched patients with an acute (< 4 weeks of persistent symptoms from diagnosis) COVID-19 infection (55.7 ± 15.2 years) served as a comparison group. We used a three-dimensional reconstruction of computed tomography imaging to measure luminal areas of the trachea, right and left main bronchi, bronchus intermediate, right and left upper lobe, and left lower lobe bronchi at proximal, middle, and distal cross-sectional points in both groups. Airway luminal area was taken as the average of the three points. We compared average lumen area of long COVID patients with acute COVID-19 individuals, using an independent samples t-test. Results: We found no significant difference comparing measurements of the following airway luminal cross-sectional areas: trachea (277.7 ± 100.4 vs. 268.0 ± 70.5 mm 2 p=0.73), right main bronchus (191.0 ± 66.1 vs. 190.1 ± 49.0 mm 2 , p=0.96), bronchus intermediate (112.3 ± 33.4 vs. 109.3 ± 27.9 mm 2 , p=0.76), right upper lobe bronchus (74.4 ± 21.0 vs. 73.7 ± 25.5 mm 2 , p=0.92), left main bronchus (129.1 ± 50.1 vs. 136.9 ± 38.0 mm 2 , p=0.58), left lower lobe bronchus (57.8 ± 18.2 vs. 59.0 ± 13.4 mm 2 , p=0.82), and left upper lobe bronchus (80.1 ± 19.5 vs. 77.9 ± 22.9 mm 2 , p=0.75) in the long COVID and acute COVID-19 groups respectively. Conclusion: In patients with long COVID, compared to those with an acute COVID-19 infection, we did not see differences in central airway luminal areas. Further analysis of a larger cohort is needed to determine whether enlarged airway luminal areas, associated with acute COVID-19, persist in long COVID. This research will expand knowledge on functional consequences for patients with long COVID. Funding: F32HL154320 to JWS; 5R35HL139854 to MJJ. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.