The spectrum of pathological findings in coronavirus disease (COVID-19) and the pathogenesis of SARS-CoV-2

Excerpt

The coronavirus disease (COVID-19) is now a worldwide pandemic and is the most significant global health crisis of our time. COVID-19 disease continues to present us with major healthcare challenges with over 8 million cases around the world and still less than optimal treatment options [1]. The virus initially was identified in Wuhan, Hubei Province, China in 2019. COVID-19 disease is caused by a novel coronavirus, which has been named “Severe Acute Respiratory Syndrome Corona virus-2 (SARS-CoV-2)” [2]. COVID-19 is highly transmissible among humans and primarily, but not only, affects the lower respiratory tract and lungs. The virus attaches to the angiotensin converting enzyme-2 (ACE-2) receptor in order to help enter the target cell by attaching its spike-like surface projections (“corona”) to the receptor. This receptor is expressed on various cell types such as myocardial cells, type II pneumocytes, enterocytes and vascular endothelium. Most of the symptomatic patients have mild flu-like features but a significant subset develop a bronchopneumonia, which clinically is the acute respiratory distress syndrome (ARDS), and leads to significant morbidity and mortality [3]. The fatality rates of COVID-19 are highest amongst older patients with concomitant comorbidities and/or patients who are immunosuppressed [4]. Our current understanding of the pathology and the pathogenesis of COVID-19 disease and SARS-CoV-2 transmission is at an early stage and much still remains to be learned [5, 6]. Additionally, there are also published reports on the pathogenesis of other coronaviruses such as SARS-CoV and MERS-CoV [7‐9]. …