The immune system and COVID-19: Friend or foe?

AIM: Coronavirus disease 2019 (COVID-19) is a novel highly contagious infection caused by SARS-CoV-2, which has been became a global public health challenge. The pathogenesis of this virus is not yet clearly understood, but there is evidence of a hyper-inflammatory immune response in critically ill patients, which leads to acute respiratory distress syndrome (ARDS) and multi-organ failure. MATERIAL AND METHODS: A literature review was performed to identify relevant articles on COVID-19 published up to April 30, 2020. The search resulted in 361 total articles. After reviewing the titles and abstracts for inclusion, some irrelevant papers were excluded. Additional relevant articles were identified from a review of citations referenced. KEY FINDINGS: SARS-CoV-2, directly and indirectly, affects the immune system and avoids being eliminated in early stages. On the other hand, the secretion of inflammatory cytokines creates critical conditions that lead to multi-organ failure. SIGNIFICANCE: The immune system which is affected by the virus tries to respond via a cytokine storm and hyperinflammation, which itself leads to further multi-organ damage and even death.