Interstitial lung disease (ILD) after COVID-19: a new fibro-inflammatory disease?

Abstract

Introduction. Nowadays post-COVID respiratory symptoms that could be associated with pulmonary fibrosis progression are of concern. Objective. To compare CT and SPECT data of patients with post-COVID pulmonary fibrosis, and to define whether the lung fibrosis progression could be predictable. Material and Methods. Changes in chest CT scan, microcirculation disorders (SPECT) and impaired lung function parameters (DLCO) were analyzed in 74 post-COVID patients with residual consequences of COVID-19. Results. A year or more after the disease, 17 % of patients had isolated ground-glass areas, 24 % of patients had ventilation mosaics and air traps, most patients had compaction of the interlobular interstitial tissue of a short UIP type (67 %); consolidation zones (38 %); zones of pulmonary fibrosis of different lengths (57 %); discoid atelectasis (39 %); bronchiectasis (26 %), pulmonary hypertension (PH) (36 %). Significant decrease of the diffusion capacity and great microcirculation disorders accompanied by more than 50 % perfusion lack were detected. We demonstrated that significant radiological and functional effects of viral pneumonia were likely to be associated with post-viral interstitial lung disease. Conclusions. 1. Complete X-ray examination with lung diffusion capacity determination can contribute to optimal dispensary observation of post-COVID patients. 2. Microcirculation disorder greater than 50 % of the norm is a predictor of the lung parenchyma changes and can contribute to the prediction of long-term effects of the disease. 3. Complete radiation monitoring is required for patients over 60 years of age; post-COVID patients having severe form of the disease; patients having respiratory complaints for more than a year, regardless of the severity of COVID-19.