Imaging, Pulmonary Function, and Histopathologic Findings of Persistent Fibrosis in a Longitudinal Cohort Three Years after Severe COVID-19 Infection.

Fibrotic-like abnormalities are present in 60% of a single-center, longitudinal, multi-ethnic cohort 3-years after severe COVID-19. They are independently associated with male sex, low BMI, shorter telomere length, increased severity of illness, and mechanical ventilation; Black race and asthma are protective. Participants with fibrotic-like abnormalities are more likely to have reduced diffusion capacity and 6-minute walk distance. Fibrotic-like abnormalities persist but modestly improve over time. Transbronchial biopsies show small airways histopathology, consistent with high prevalence of air trapping in expiration, and infrequent interstitial thickening. This study highlights the need for continued monitoring of patients with persistent fibrosis after severe COVID-19.