IL2 and delirium: Other blood-based inflammatory mediators which predicted delirium or were elevated during delirium in some studies include C-reactive protein (CRP) [10, 11], IL-1β [12], IL-2 [9, 13], IL-8 [7], tumor necrosis factor alpha (TNFα) [9, 13], and soluble TNFα receptor 1 and 2 [12, 14].