Low-dose radiotherapy for COVID 19: A radioimmunological perspective

The world is fighting the onslaught of COVID 19 for the last 10 months, ever since the first case was reported in December 2019 in Wuhan, China. Now, it has spread to over 200 countries. COVID 19-associated respiratory syndrome is causing a lot of mortality and morbidity. There are reports suggesting that the complications and ARDS associated with COVID 19 is an immune response reaction. The cytokine storm associated with severe cases of COVID 19 acts as a cause of death in many sick patients. It has been shown that COVID 19 is associated with a peculiar immune profile: Decrease in CD3, CD4, CD8, natural killer cell and B-cells; Rise in interleukin (IL)-4, IL-6 and tumor necrosis factor (TNF) alpha; Decrease in IL-10; Decrease in interferon-gamma. Low-dose radiotherapy (LDRT) immunosuppressive features resulting from M2 macrophage phenotype activation, increase in IL-10, transforming growth factor beta, a decrease in IL-6, TNF alpha and an increase in CD3, CD4, and CD8 T cell counts may negate the harmful effects of cytokine release syndrome. Literature review shows that radiation was previously used to treat viral pneumonia with a good success rate. This practice was discontinued in view of the availability of effective antibiotics and antivirals. As there are no scientifically proven treatment for severe COVID 19-associated respiratory distress today, it is prudent that we understand the benefits of LDRT at this critical juncture and take rational decisions to treat the same. This article provides an radioimmunological rationale for the treatment of immune crisis mediated complications in severe cases of COVID 19.