Prognostic value of senescence, lymphatic proliferation, and histology in post-COVID-19 interstitial lung disease.

Masson bodies identified in 3-month cryobiopsy were associated with higher forced vital capacity at 6 months follow-up.

• Finding derived from multivariate regression analysis of cryobiopsy histopathological findings
• Masson bodies are histological features associated with organizing pneumonia patterns
• The relationship suggests that certain histological patterns at 3 months may predict better pulmonary function outcomes at 6 months
• Study performed at Vall d'Hebron University Hospital between March 2020 and February 2021

Higher expression of the senescence marker P-16 in lung tissue was associated with decreased carbon monoxide transfer test (DLCO) values at 6 months.

• P-16 is a marker of cellular senescence analyzed in lung cryobiopsy samples
• Association identified through multivariate regression analysis
• DLCO impairment reflects reduced gas exchange capacity
• Samples were obtained from the first 66 patients presenting with respiratory symptoms, radiological alterations, and decreased pulmonary function tests at 3-month post-hospitalization follow-up

Higher expression of the lymphatic proliferation marker D2-40 in lung tissue was associated with decreased carbon monoxide transfer test values at 6 months.

• D2-40 is a marker of lymphatic proliferation analyzed immunohistochemically in cryobiopsy samples
• Association identified through multivariate regression analysis alongside P-16
• Finding suggests lymphatic proliferation contributes to impaired gas exchange in post-COVID-19 ILD
• Cryobiopsies were performed at the 3-month follow-up visit after hospital discharge

A large proportion of hospitalized COVID-19 patients developed persistent respiratory sequelae requiring follow-up and biopsy evaluation.

• 4332 patients were hospitalized at Vall d'Hebron University Hospital due to COVID-19 pneumonia between March 2020 and February 2021
• 1403 patients were seen in the Respiratory Clinic 3 months after discharge
• The first 66 patients presenting with respiratory symptoms, radiological alterations, and decreased pulmonary function tests underwent cryobiopsy for diagnostic purposes
• This represents a prospective observational study design

Post-COVID-19 ILD sequelae can persist beyond 6 months after hospital discharge in a subset of patients, and the pathophysiological mechanisms remain poorly understood.

• The study was specifically designed to evaluate patients with ILD persisting beyond 6 months
• Histopathological patterns, cellular senescence, and lymphatic proliferation were evaluated as potential prognostic factors
• Lung cryobiopsies were used to analyze histopathological findings and expression of P16 and D2-40
• The study identifies cellular senescence and lymphatic proliferation as novel pathophysiological mechanisms potentially involved in post-COVID-19 ILD