MAPT and Lewy body dementia: Similarly, previous research suggests that the core CSF biomarkers typically used to support AD diagnosis amyloid β peptide (Aβ1-42), total tau (tTau), and phosphorylated tau (pTau) offer limited diagnostic accuracy in distinguishing DLB from AD, as they are abnormal in approximately 25%–40% of DLB patients due to comorbid AD pathology (Lehmann et al., 2020).