AbstractBackgroundThe early stage of Alzheimer’s Dementia (AD) development has been linked to the breakdown of the blood‐brain barrier (BBB), which is maintained by pericytes and other cell types. Platelet‐derived growth factor receptor‐β (PDGFRβ) has been identified as a novel biomarker of BBB‐associated capillary pericyte damage. Our study aimed to explore the potential association between PDGFRβ and neuropathological diagnosis of Alzheimer’s Dementia, as well as GFAP levels‐ a widely recognized AD biomarker that is present in both serum and cerebrospinal fluid (CSF).MethodA cohort of 48 subjects in the Arizona Study of Aging and Neurodegenerative Diseases (AZSAND) with serum and CSF samples, obtained at the time of death, were included in this cross‐sectional study. Enzyme‐linked immunosorbent assay (ELISA) was utilized to detect PDGFRβ and GFAP in serum and CSF. Statistical analyses were performed using Spearman’s rank correlation and Mann‐Whitney U test.ResultBaseline characteristics were similar between AD (n = 28) and non‐AD groups(n = 20). There was a significant increase in levels of serum PDGFRβ in AD compared to unmatched non‐AD subjects (Mean: 6348.2pg/ml vs 4730.1pg/ml, p<0.05). In addition, PDGFRβ in both CSF and serum correlated with Glial Fibrillary Acidic Protein (GFAP), a well‐known biomarker associated with AD (Spearman’s 𝝆 = 0.42, P< 0.01, Spearman’s 𝝆 = 0.46, P< 0.01, respectively.)ConclusionPDGFRβ, a putative marker of BBB integrity, is elevated in the serum of individuals with Alzheimer’s Dementia (AD) and is correlated with GFAP levels measured in both serum and cerebrospinal fluid (CSF). While these findings are promising and suggest the potential use of PDGFRβ as a blood‐based biomarker for AD pathophysiology, further studies with larger sample sizes are warranted to validate the potential of PDGFRβ as a biomarker for AD.