Increased Systemic Immune-Inflammation Index as a Novel Indicator of Alzheimer's Disease Severity.

SII, a novel inflammatory marker, was associated with dementia severity in patients with AD. Compared with PLR and SII, NLR was more strongly correlated with dementia severity. In future studies with larger populations, SII and NLR values can be used to determine dementia severity and establish follow-up plans for patients with high dementia risk.