The cytokine storm of COVID-19: a spotlight on prevention and protection.

Over-activity of chemotaxis triggers a macrophage activation syndrome (MAS) resulting in the release of pro-inflammatory cytokines. IL-6 and TNF- α are at the forefront of hyper-inflammation. The inflammatory cascade induces endothelial activation and capillary leak, leading to circulatory collapse and shock. As endothelial dysfunction persists, there is activation of the clotting cascade and microvascular obstruction. Continued endothelial activation results in multi-organ failure, regardless of pulmonary tissue damage. We propose that targeting the endothelium may interrupt this cycle. Immuno-modulating therapies have been suggested, however, further data is necessary to confirm that they do not jeopardize adaptive immunity. Inhibition of IL-6 and the Janus Kinase, signal transducer and activator of transcription proteins pathway (JAK/STAT), are favorable targets. Remote ischemic conditioning (RIC) reduces the inflammation of sepsis in animal models and should be considered as a low risk intervention, in combination with cardiovascular protection.