Corona Virus Infectious Disease 19 (Covid-19)

The current COVID-19 outbreak was caused by a new coronavirus SARS-CoV-2. It accesses host cells through the angiotensin-converting enzyme 2 (ACE2) protein which is expressed by endothelial cells (EC) and very abundantly expressed in the lungs. SARS-CoV-2 uses a surface glycoprotein (peplomer) called a spike to access host cells and ACE2 has been revealed to be a co-receptor for coronavirus entry. The antigen presentation of SARS-CoV mainly depends on the MHC I molecule but MHC II also contributes to the presentation. Based on the mechanism of a common acute viral infection the antibody profile against the SARS-CoV virus contains characteristic pattern of IgM and IgG production. By the end of week 12 SARS-specific IgM antibodies disappear whereas IgG antibodies can last in a longer period of time which shows IgG antibodies can mainly hold a protective role and SARS-specific IgG antibodies mainly are S-specific and N-specific antibodies. Clinical manifestations are not only found in mucosa in the airways but also in the cardiovascular system kidneys central nervous system pregnancy skin oral cavity and digestive system. The diagnose of clinical presentation of COVID-19.