Pathogensis of Covid-19: An Update

The vital step for life cycle for any kind of virus is an attachment and ensuing entry in the cell of the host. It has been proved the attachment of SARSCoV2 is attained by interlinkage of ACE -2 (angiotensin converting enzyme 2) and spike surface S glycoprotein. the impetus of the viral storm plummets on the distal airways, alveoli of lung, having elevated expression of ACE2, especially in the pneumocytes that is type II pneumocytes. Damage to type pneumocytes causes release inflammatory mediators stimulate macrophages to release cytokines such as IL-1(interleukin-1) , IL-6(Interleukin-6), tumor necrotic factor alpha(TNF- α) causing cytokine storm these cytokines come to blood stream and cause endothelial cells to undergo dilatation increasing capillary permeability leading to leaking of plasma into interstitial spaces and potentially into the alveoli.It can also affects other organs such as brain, heart, kidneys and by causing systemic inflammatory response (SIRS) can cause multiorgan failure.

Keywords: COVID-19, ACE-2, Cytokines