Bellaver B, Ferrari-Souza JP, da Ros LU, et al. - In this systematic review and meta-analysis, researchers ascertained if fluid and imaging astrocyte biomarkers are altered in Alzheimer disease (AD). The PubMed and Web of Science databases were explored for articles describing fluid or imaging astrocyte biomarkers in AD. The first search yielded 1,425 articles. Following the application of exclusion criteria, 33 articles (a total of 3,204 people) measuring levels of glial fibrillary acidic protein, S100B, chitinase-3-like protein 1 (YKL-40), and aquaporin 4 in the blood and CSF, as well as monoamine oxidase-B indexed by PET ¹¹ C-deuterium-L-deprenyl, were included. Despite significant progress, the use of astrocyte biomarkers in AD is still in its early days. This meta-analysis found that astrocyte biomarkers are consistently altered in AD and support further research into their inclusion in the AD clinical research framework for observational and interventional studies.