IL6 and Alzheimer disease: However, in the same report, Lanzrein et al. describe no significant differences between AD subjects and controls regarding serum and CSF levels of interleukin-1 beta (IL-1β), IL-1 receptor antagonist (IL-1ra), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), the soluble TNF receptors type I and II (sTNFR 1 and 2), and the acute phase protein alpha1-antichymotrypsin (α1-ACT).