The role of inflammation in the development of complications caused by COVID-19: A Review Study

• Published in: Payavard salamat Vol. 16; no. 4; pp. 346 - 361
• Main Authors: Alireza Monadi Sefidan, Ziba Majidi
• Format: Journal Article
• Language: Persian
• Published: Tehran University of Medical Sciences 01-10-2022
• Subjects: covid-19; cytokine storm; gastrointestinal complications; inflammation; liver complications; oxidative stress
• ISSN: 1735-8132; 2008-2665

Background and Aim: It is important to understand how inflammation caused by COVID-19 affects patients and leads to more complications and diseases. According to the importance of controlling COVID-19 related complications, the current study was designed to evaluate the inflammation caused by COVID-19 and its related complications.  Materials and Methods: The present study is a review study. Studies were retrieved from PubMed, Web of science, Scopus and Google scholar databases. Finally, according to the purpose of the study, the relevant resources were selected by the researchers and a summary of their results was presented in this study. Results: The present study showed that SARS-CoV-2 viruses enter their genome into the host cell after entering the cell by the spike protein (S) and the important receptor of coronavirus, angiotensin converting enzyme 2 (ACE - 2), and causes the onset of cytokine storms and consequently increase of primary cytokines involved in inflammation. IL-6, IL-8, TNF-α and IL-1 cytokines are key factors; These factors in turn activate macrophages, dendritic cells (DC) and other immune cells. Studies revealed that the inflammation caused by SARS-CoV-2 in the liver by inducing IL-6 activates the JAKs/STAT3 pathway, whose receptor is only found in the liver and immune cells, and causes cytokine release syndrome. Cytokines also cause the release of reactive oxygen species (ROS), superoxide anion, and nitric oxide, so that all of them can damage myocardial cells and cause insulin resistance and diabetes. In addition, the increase of inflammatory cytokines such as IL4, IL10 and IL6 and immune cells lead to cardiac disorders such as arrhythmia. The entry of the virus into the digestive system reduces the bacteria secreting butyrate (with anti-inflammatory effects) and leads to the induction of severe inflammation. Also, corona virus causes obsessive-compulsive disorder, depression and other neurological disorders by increasing pro-inflammatory cytokines and increasing the activity of indoleamine 2,3 dioxygenase (IDO). Conclusion: Studies have shown that the inflammation caused by COVID-19 plays an important role in the development of the related complications such as disorders in the digestive, hepatic, cardiac, neurologic, pancreas systems and other organs. Therefore, targeting cytokines can potentially improve survival and reduce mortality.