ABSTRACT NUMBER: ESOC2026A1015 EFFECT OF ACUTE INTRACEREBRAL HEMORRHAGE ON PLASMA AMYLOID-BETA AND P-TAU217

Abstract Background and aims To explore the effect of time from intracerebral hemorrhage (ICH) on plasma Aβ37,Aβ40,Aβ42,and p-tau217 concentrations in patients with spontaneous ICH due to cerebral amyloid angiopathy (CAA) or hypertension (HTN). Methods Pseudo-longitudinal analysis of a prospective cohort study including patients with acute spontaneous CAA or HTN-related ICH presenting to the Massachusetts General Hospital between 1996 and 2015. Plasma biomarkers were measured using the Meso Scale Discovery platform. Effect of time from ICH was assessed using linear models and adopting specific timepoints after ICH (7, 15, 30, 90, and ≥90 days) deemed clinically relevant. Results In patients with CAA-ICH (n=157, 70.5y±8.4, 54% males), Aβ37, Aβ40, and Aβ42 concentrations were significantly increased at 7-15 days post-ICH (P from 0.002 to 0.041) compared to 0-7 days and decreased thereafter. In patients with HTN-ICH (n=105, 67.7y±11.1, 57% males) only Aβ40 was increased at 7-15 days (P=0.13). No changes in p-tau217 were observed in either ICH group. Conclusions These preliminary findings suggest that plasma Aβ37, Aβ40, and Aβ42 concentrations might increase 7-15 days after lobar ICH, pointing to mobilization of vascular and parenchymal amyloid in the bloodstream following acute ICH. Pending further validation, these results might aid in the interpretation of plasma Aβ markers in the period following intracerebral hemorrhage. Conflict of interest Francesco Bax: nothing to disclose Lei Liu: nothing to disclose Elif Gockal: nothing to disclose Mitchell Jacob Horn: nothing to disclose Andrew Warren: nothing to disclose Adriana Saba: nothing to disclose Zahra Shirzadi: nothing to disclose Zora Y. Dipucchio: nothing to disclose Kristin M. Schwab: nothing to disclose M. Edip Gurol: nothing to disclose Anand Viswanathan: nothing to disclose Jasmeer P. Chhatwal: nothing to disclose Steven M. Greenberg: nothing to disclose