Blood Astrocyte Biomarkers in Alzheimer Disease
Sarah Holper, Paula Loveland, Leonid Churilov, Dominic Italiano, Rosie Watson, Nawaf Yassi
Abstract
BACKGROUND AND OBJECTIVES: Neuroinflammation, particularly early astrocyte reactivity, is a significant driver of Alzheimer disease (AD) pathogenesis. It is unclear how the levels of astrocyte biomarkers change in patients across the AD continuum and which best reflect AD-related change. We performed a systematic review and meta-analysis of 3 blood astrocyte biomarkers (glial fibrillary acidic protein [GFAP], chitinase-3-like protein 1 [YKL-40], and S100B) in patients clinically diagnosed with AD. METHODS: method with a random-effects model. The review was prospectively registered on PROSPERO (registration number CRD42023458305). RESULTS: = 0.0048). No significant differences in blood S100B levels were identified. DISCUSSION: We demonstrated significant elevations in blood GFAP and YKL-40 levels in patients on the AD continuum compared with CU individuals. Furthermore, within the AD clinical spectrum, significant elevation correlated with more advanced disease stage. Our findings suggest that both biomarkers reflect AD-related pathology. Our findings are limited by the lack of cultural and linguistic diversity in the study populations meta-analyzed. Future meta-analyses using a biomarker-defined AD population are warranted.