%0 Journal Article
%T Clinical Manifestations of Cytokine Storm and Immune Response to COVID-19: Literature Review
%A Saeedeh Kowsarnia
%J Open Journal of Internal Medicine
%P 151-174
%@ 2162-5980
%D 2021
%I Scientific Research Publishing
%R 10.4236/ojim.2021.113012
%X Spreading COVID-19 disease caused by coronavirus 2 causes tremendous health challenges worldwide. Owing to a high transmission rate, fast-spreading disease, asymptomatic carriers, and high infectivity, we observe a pandemic status that we follow today. Although there are different reports of case fatality rates around the globe, the primary determinant of mortality is age. Symptoms of COVID-19 disease vary from asymptomatic individuals to severe acute respiratory distress syndrome (ARDS) and death. The most common complication of COVID-19 is ARDS. Hyperinflammation due to excessive immune response to coronavirus is the leading cause of severe symptoms seen in the course of COVID-19. The virus enters cells utilizing the S1 subunit through the ACE2 receptor. The innate immune response is the primary immune reaction to virus entry. RNA viruses, including corona-virus, replicate in the cytoplasm, assemble, and then exit by exocytosis. Some suggest that SARS-Cov2 uses cell-cell fusion to infect adjacent cells. Different sensors detect the virus particles in the endosomal compartment and cytoplasm, and infected cells induce an immune response to surrounding cells. As a result, the production of cytokines and chemokines such as interferons (INFs) will be augmented. Since coronavirus uses different means to evade the immune system, it is difficult for immune cells to ¡°sense¡± them; thus, the coronavirus response is not adequate. It has been showing that even a sufficient level of immunoglobulin response couldn¡¯t neutralize virus replication. Therefore, the innate immune response is unable to eradicate SARS-Cov2, causes overexpression of cytokines and chemokines that cannot eliminate the virus. Diminished INFs secretion and apoptosis of regulatory T cells (Treg) are the leading cause of dysregulated immune response in a cytokine storm. Inflammatory cells attack infected and uninfected cells, causing more inflammation and apoptosis of endothelial and epithelial cells. In the end, organ failure occurs due to immune cells¡¯ overactivity, cell proliferation, hemorrhage, microthrombi, and remodeling of tissue cells. This review discusses the immune response and pathomechanisms of the associated symptoms in COVID-19.
%K COVID-19
%K SARS-Cov 2
%K Clinical Symptoms
%K Cytokine Storm
%K Immunological Manifestation
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=111765