Emerging complications of COVID-19 in a subset of Indian population: a pathological review with clinico-radiological case scenarios

ABSTRACT

Background: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was declared a pandemic by the World Health Organization on 11 March 2020 has been reported in most countries around the world since its origins in Wuhan, China. As of September 2021, there have been over 229 million cases of COVID-19 reported worldwide, with over 4.7 million COVID-19–associated deaths. Body The devastating second wave of the COVID-19 pandemic in India has seen a rise in various extrapulmonary manifestations. One of key components in the pathogenesis of COVID-19 is downregulation of ACE-2, which is expressed on many organs and counterbalances the pro-inflammatory effects of ACE/angiotensin-II axis. This leads to influx of inflammatory cells into alveoli, increased vascular permeability and activation of prothrombotic mediators. Imaging findings such as ground glass opacities, interlobular septal thickening, vascular dilatation and pulmonary thrombosis correlate well with the pathogenesis. Conclusion: We hypothesize that the systemic complications of COVID-19 are caused by either direct viral invasion or effect of cytokine storm leading to inflammation and thrombosis or a combination of both. Gaining insights into pathobiology of SARS-CoV-2 will help understanding the various multisystemic manifestations of COVID-19. To date, only a few articles have been published that comprehensively describe the pathophysiology of COVID-19 along with its various multisystemic imaging manifestations.