Organizing pneumonia in hospitalized COVID-19 patients: risk factors and long-term outcomes

Abstract

Background: Some patients develop post-COVID-19 organizing pneumonia (OP) that is responsive to corticosteroid treatment. This multicenter, case-control study of patients hospitalized for COVID-19 sought to determine the prevalence, risk factors, radiological outcomes, and evolution after treatment.

Methods: We included 153 consecutive patients with OP and 140 without OP who required hospitalization because of COVID-19 from February to April 2020. OP patients were followed up for 12 months, with visits at 1, 3, 6, and 12 months after hospital discharge.

Results: Risk factors for OP at hospital admission were advanced age, previous respiratory disease, and elevated C-reactive protein levels. Follow-up computed thoracic (CT) scans performed one year after admission showed progressive improvement in radiological involvement; however, up to 57% of patients with OP remained with fibrotic-like changes. Multivariate analysis showed a significant association of fibrotic pattern with older age, high dose of corticosteroids, and extensive parenchymal lung involvement on admission CT scans.

Conclusions: Following COVID-19 OP, fibrotic-like changes may persist over the long term. Higher dose of corticosteroids does not seem to be associated with a better prognosis.

Supplementary Information: The online version contains supplementary material available at 10.1186/s41479-025-00169-9.

Keywords: COVID-19; Corticosteroids; Organizing pneumonia.

Fig. 1

Distribution (geometric mean and 95% confidence interval) of blood parameters according to period (admission/discharge) and persistent pneumonitis status at discharge (yes/no)

Fig. 2

Radiological evolution of OP-like pattern group during hospitalization, 1 month and 1 year after discharge