The after-effects of COVID-19 are considerable, especially in people who have a serious illness. Recent data show that pulmonary fibrosis can occur secondarily after infection, especially in patients who suffered from severely impaired diffusion capacity during the acute infection1.
At present, the long-term pulmonary effects of COVID-19 remain speculative. "However, we know that the severity of COVID-19 is related to the symptoms at patient discharge," said Prof. Francesco Blasi of the University of Milan, Italy. In particular, people who fall ill with COVID-19 so severely that admission to an intensive care unit is necessary to seem to be at risk. In the first large series of hospitalized patients with COVID-19 in Wuhan, China, the thoracic CT showed bilateral ground-glass opacity (GGO) in all patients with or without consolidation and with a lower lobe predominance2.
Although the virus is eradicated in those who have recovered from COVID-19, eliminating the cause of lung damage does not in itself preclude the development of progressive, fibrotic irreversible interstitial lung disease. As Prof. Blasi pointed out, early analysis of patients with COVID-19 after discharge from the hospital showed that more than a third of those who recovered, develop fibrotic abnormalities3.
In addition, 47% of the patients were found to have impaired diffusion capacity for carbon monoxide (30.4% of them with mild illness, 42.4% with pneumonia, and 84.2% with severe pneumonia) and 25% of the patients had reduced total lung capacity3. "Not only diffusion disturbance but also CT changes are observed in patients with severe disease," said Prof. Blasi.
For the treatment of pulmonary fibrosis associated with COVID-19, a range of therapies from traditional Chinese medicine to steroids and antifibrotics have been tested. "In our experience, steroids seem to work; they improve physical resilience. But I think that antifibrotics could be another interesting approach," concluded Prof Blasi.
1. Blasi S. COVID-19: Long term impact: the lung and beyond ERS International Virtual Congress 2020, 7-9 Sept.
2. Wang D, et al JAMA 2020;323:1061-1069.
3. Mo X, et al Eur Respir J 2020:55:2001217.