IL6 and brain ischemia: In another study, by assessment of initial ischemic lesion size and neurological dynamics during 1 month of acute brain ischemia, high plasma level of IL-6 in the acute phase of stroke was shown to be a strong predictor of poor outcome for aged rather than for younger patients.   23  Clark et al. measured plasma levels of IL-6, fibrinogen, white blood cells (WBCs), and serum albumin as acute phase response (APR) in 4±2 days of onset in ischemic stroke patients.