Plasma Phosphorylated Tau 217 Reshapes Diagnostic Classification in a Real-World Memory Clinic Cohort
Nora Maerean, Sofia Litchev, George R. Jackson, Joseph S. Kass, Valory N. Pavlik, Chi-Ying R. LinBackground:
Plasma phosphorylated tau-217 (ptau217) accurately identifies Alzheimer disease (AD), but its impact on real-world clinical diagnosis remains unclear. We evaluated the effect of plasma ptau217 on diagnostic reclassification in a memory disorders clinic.
Methods:
We retrospectively reviewed 100 patients evaluated for memory impairment. Initial clinical diagnoses were established based on clinical evaluation, neuropsychological testing, and brain MRI without plasma biomarker results. Follow-up diagnoses were assigned after the availability of plasma ptau217 results. Diagnostic reclassification was assessed using binary (ptau217 > 0.18) and higher threshold (ptau217 > 0.325) classification schemes. McNemar tests evaluated reclassification patterns, with subgroup analyses by apolipoprotein E (
Results:
Diagnosis reclassification occurred in 37.8% and 46.9% of patients using the lower and higher threshold, respectively (both
Conclusions:
Plasma ptau217 meaningfully influences diagnostic decisions in memory clinic practice and may be particularly valuable for refining diagnoses among