The growth factor/ cytokine midkine may participate to cytokine storm and contribute to the pathogenesis of SARS-CoV-2 infected patients

Abstract

The current coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged in Wuhan, China and has rapidly become global challenges, creating major challenges to health systems in almost every country in the world it has turned into a pandemic. COVID-19 poses a risky clinical situation that can range from mild illness to severe respiratory failure requiring admission to intensive care. It is known to cause cytokine storm in some critically ill patients. However, more and more evidence showed that there is a dramatic increase in cytokine levels in patients diagnosed with COVID-19. Midkine (MK) is involved in various physiological and pathological processes, which some of them are desired and beneficial such as controlling tissue repair and antimicrobial effects, but some others are harmful such as promoting inflammation, carcinogenesis and chemo-resistance. Also, MK is expressed in inflammatory cells and released by endothelial cells under hypoxic conditions. Considering all this information, there are strong data that MK, an important cytokine known to increase in inflammatory diseases, may overexpressed in patients who are positive for COVID-19. The overexpression of MK reveals a picture leading to fibrosis in the lung damage. Therefore, questions arise about how the concentration of MK changes in CoVID-19 patients and can we use it as an inflammation biomarker or in the treatment protocol in the future.