TNF and Cognitive impairment: For example, high levels of TNF-α and low levels of TNF-β have been detected in CSF samples from patients with mild cognitive impairment who progressed to AD, and the cytokines IL-1β, IL-6, and TNF-α, tend to increase slowly, while the cytokines IL-18, MCP-1, and IP-10 peak at a certain stage of the disease (140, 141).