id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-260852-u0gpklj7	Osman, Mohammed	Impaired natural killer cell counts and cytolytic activity in patients with severe COVID-19	2020-10-19		.txt	text/plain	2270	139	42	We recently postulated that the inflammatory response in patients with severe COVID-19 disease is not inhibited by natural killer (NK) cells, resulting in a "cytokine storm." Here, we assessed the NK-cell functional activity and the associated cytokines and soluble mediators in hospitalized COVID-19 patients. 6, 7 Rapid activation of the innate immune system accompanied by an aggressive inflammatory response, associated with a surge in many proinflammatory cytokines, has been reported, especially in patients developing severe manifestations of COVID-19. 5, 8 This "hypercytokinemia" or "cytokine storm" is thought to be driving the COVID-19-related ARDS, 5, 8 and associated hyperferritinemia is reminiscent of macrophage-activation syndrome (MAS) or secondary hemophagocytic lymphohistiocytosis (HLH; sHLH). 5, 32 Here, we describe impaired NK-cell cytolytic activity associated with a loss of cytokines important in NK-cell stimulation in severe COVID-19 patients. 33 In conclusion, this study demonstrates that reduced NK-cell counts and impaired cytolytic activity are important characteristics associated with severe COVID-19-related hyperinflammation.	./cache/cord-260852-u0gpklj7.txt	./txt/cord-260852-u0gpklj7.txt