1. Alveolar membrane and capillary function in COVID-19 convalescents: insights from chest MRI.
- Author
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Kern AL, Pink I, Bonifacius A, Kaireit T, Speth M, Behrendt L, Klimeš F, Voskrebenzev A, Hohlfeld JM, Hoeper MM, Welte T, Wacker F, Eiz-Vesper B, and Vogel-Claussen J
- Subjects
- Humans, Male, Female, Middle Aged, Prospective Studies, Longitudinal Studies, Adult, Pulmonary Alveoli diagnostic imaging, Capillaries diagnostic imaging, Capillaries physiopathology, Aged, Lung diagnostic imaging, COVID-19 diagnostic imaging, Magnetic Resonance Imaging methods, SARS-CoV-2
- Abstract
Objectives: To investigate potential presence and resolution of longer-term pulmonary diffusion limitation and microvascular perfusion impairment in COVID-19 convalescents., Materials and Methods: This prospective, longitudinal study was carried out between May 2020 and April 2023. COVID-19 convalescents repeatedly and age/sex-matched healthy controls once underwent MRI including hyperpolarized
129 Xe MRI. Blood samples were obtained in COVID-19 convalescents for immunophenotyping. Ratios of129 Xe in red blood cells (RBC), tissue/plasma (TP), and gas phase (GP) as well as lung surface-volume ratio were quantified and correlations with CD4+ /CD8+ T cell frequencies were assessed using Pearson's correlation coefficient. Signed-rank tests were used for longitudinal and U tests for group comparisons., Results: Thirty-five participants were recruited. Twenty-three COVID-19 convalescents (age 52.1 ± 19.4 years, 13 men) underwent baseline MRI 12.6 ± 4.2 weeks after symptom onset. Fourteen COVID-19 convalescents underwent follow-up MRI and 12 were included for longitudinal comparison (baseline MRI at 11.5 ± 2.7 weeks and follow-up 38.0 ± 5.5 weeks). Twelve matched controls were included for comparison. In COVID-19 convalescents, RBC-TP was increased at follow-up (p = 0.04). Baseline RBC-TP was lower in patients treated on intensive care unit (p = 0.03) and in patients with severe/critical disease (p = 0.006). RBC-TP correlated with CD4+ /CD8+ T cell frequencies (R = 0.61/ - 0.60) at baseline. RBC-TP was not significantly different compared to matched controls at follow-up (p = 0.25)., Conclusion: Impaired microvascular pulmonary perfusion and alveolar membrane function persisted 12 weeks after symptom onset and resolved within 38 weeks after COVID-19 symptom onset., Clinical Relevance Statement:129 Xe MRI shows improvement of microvascular pulmonary perfusion and alveolar membrane function between 11.5 ± 2.7 weeks and 38.0 ± 5.5 weeks after symptom onset in patients after COVID-19, returning to normal in subjects without significant prior disease., Key Points: • The study aims to investigate long-term effects of COVID-19 on lung function, in particular gas uptake efficiency, and on the cardiovascular system. • In COVID-19 convalescents, the ratio of129 Xe in red blood cells/tissue plasma increased longitudinally (p = 0.04), but was not different from matched controls at follow-up (p = 0.25). • Microvascular pulmonary perfusion and alveolar membrane function are impaired 11.5 weeks after symptom onset in patients after COVID-19, returning to normal in subjects without significant prior disease at 38.0 weeks., (© 2024. The Author(s).)- Published
- 2024
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