Influence of bronchopulmonary diseases on the course and outcome of COVID-19: a literature review

The SARS-CoV-2 coronavirus has become a major global health concern. Infection with SARS-CoV-2 has caused millions of deaths worldwide, and the case fatality rate has been found to be largely related to pre-existing clinical conditions. The main clinical manifestation of COVID-19 is the presence of respiratory symptoms. Severe complications of COVID-19 are most often observed in people with significant medical histories. The SARS-CoV-2 virus primarily attacks the respiratory system, causing pneumonia and acute respiratory distress syndrome, which can lead to severe systemic inflammation, multiple organ dysfunction, and death, especially in patients with pre-existing comorbidities. A number of meta-analyses strongly suggest that comorbid respiratory diseases, including chronic obstructive pulmonary disease and interstitial lung diseases, are factors in the development of severe forms of COVID-19, worsening patient outcomes and survival rates. Studies have shown an association between adverse outcomes of COVID-19 and the expression level of the angiotensin-converting enzyme 2 (ACE2) in these patients. Regarding other respiratory system pathologies, such as bronchial asthma and cystic fibrosis, it is known that the main unfavorable factor is long-term immunosuppressive pharmacotherapy preceding infection. In this article, we highlight the main respiratory comorbidities to better understand the pathogenesis of COVID-19.