MAPT and early-onset autosomal dominant Alzheimer disease: Recent findings endorse CSF testing for anti-amyloid-β autoantibodies as a diagnostic method for CAA-ri, especially in atypical or nonhemorrhagic cases.3Updated meta-analyses indicate a distinct CSF biomarker profile in sporadic CAA, revealing decreased levels of Aβ42, Aβ40, and Aβ38, along with increased total tau and phosphorylated tau compared with healthy controls and Alzheimer's disease (AD) groups.4These profiles could improve diagnosis in unclear cases.