BACKGROUND: The relationship between peripheral cytokines and neuroimaging biomarkers for Alzheimer's disease (AD) is not yet well established. OBJECTIVE: To determine the association of cytokine plasma levels with brain amyloid deposition, cortical glucose metabolism, hippocampal volume, and white matter lesions (WMLs) in older adults with mild cognitive impairment (MCI). METHODS: We recruited 50 older individuals with amnestic MCI (25 men and 25 women
median age, 75 years) and performed plasma analysis, RESULTS: The plasma levels of IL-2Ra, IL-3, IL-5, IL-7, IL-9, IL-16, IL-18, fibroblast growth factor (FGF-basic), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage inflammatory protein-1α (MIP-1α), regulated on activation, normal T-cell expressed and secreted (RANTES), tumor necrosis factor-α (TNF-α), cutaneous T-cell attracting chemokine (CTACK), growth-regulated oncogene α (GROα), hepatocyte growth factor (HGF), interferon-α2 (IFN-α2), leukemia inhibitory factor (LIF), monocyte chemoattractant protein-3 (MCP-3), β-nerve growth factor (β-NGF), stem cell factor (SCF), stem cell growth factor-β (SCGF-β), and TNF-related apoptosis-inducing ligand (TRAIL) were significantly associated with global PiB uptake, whereas those of IL-7 and GROα were significantly associated with hippocampal volume after covariate adjustment and false discovery rate correction. CONCLUSIONS: Plasma cytokines are associated with brain amyloid deposition rather than brain dysfunction or hippocampal atrophy. Moreover, cytokines may play important roles in early-stage AD pathophysiology.