Early pulmonary fibrosis-like changes between delta and pre-delta periods in patients with severe COVID-19 pneumonia on mechanical ventilation

• Published in: Scientific reports 2024-10, Vol.14 (1), p.26101-9, Article 26101
• Main Authors: Yoo, Jung-Wan, Kim, Won-Young, Chung, Chi Ryang, Cho, Young-Jae, Lee, Jinwoo, Jegal, Yangjin, Kim, Junghyun, Joh, Joon-Sung, Park, Tae Yun, Baek, Ae-Rin, Park, Joo Hun, Chae, Ganghee, Hwang, Jung Hwa, Song, Jin Woo
• Format: Article
• Language: English
• Subjects: 692/308; 692/308/409; 692/699; 692/699/1785; Aged; COVID-19 - complications; COVID-19 - diagnostic imaging; COVID-19 - pathology; Critical Illness; Female; Humanities and Social Sciences; Humans; Lung - diagnostic imaging; Lung - pathology; Male; Mechanical ventilation; Middle Aged; multidisciplinary; Pulmonary Fibrosis - diagnostic imaging; Pulmonary fibrosis-like change; Republic of Korea - epidemiology; Respiration, Artificial; SARS-CoV-2; SARS-CoV-2 - isolation & purification; Science; Science (multidisciplinary); Tomography, X-Ray Computed
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-77405-7

It remains unclear whether pulmonary fibrosis-like changes differ in patients with different SARS-CoV-2 variants. This study aimed to compare pulmonary fibrotic changes between two SARS-CoV-2 variant periods (delta vs. pre-delta) in critically ill patients with SARS-CoV-2 pneumonia. Clinical data and chest CT images of patients with SARS-CoV-2 pneumonia receiving mechanical ventilation were collected from 10 hospitals in South Korea over two periods: delta (July-December, 2021; n  = 64) and pre-delta (February, 2020-June, 2021; n  = 120). Fibrotic changes on chest CT were evaluated through visual assessment. Of 184 patients, the mean age was 64.6 years, and 60.5% were ale. Fibrosis-like changes on chest CT (median 51 days from enrollment to follow up CT scan, interquartile range 27–76 days) were identified in 75.3%. Delta group showed more fibrosis-like changes (≥ 2) (69.8% vs. 43.1%, P  = 0.001) and more frequent reticulation and architectural distortion+/-parenchymal band than pre-delta group. Even after propensity score matching with clinical variables, delta group had more severe (≥ 2) fibrosis-like changes (71.4% vs. 38.8%, P  = 0.001), and more frequent reticulation and architectural distortion+/-parenchymal band than pre-delta group. Our data suggest that critically ill patients with SARS-CoV-2 in delta period had more severe pulmonary fibrosis-like changes than those in pre-delta period.