Novel immunoassay detecting p-Tau Thr217 distinguishes Alzheimer’s Disease from other dementias

Objective

To investigate whether p-tau T217 assay in cerebrospinal fluid (CSF) can distinguishes Alzheimer’s disease from other dementias and healthy controls.

Methods

We developed and validated a novel Simoa immunoassay to detect p-tau T217 in CSF. There was a total of 190 participants from three cohorts with AD (n = 77) and other neurodegenerative diseases (n = 69) as well as healthy subjects (n = 44).

Results

The p-tau T217 assay (cut-off 242 pg/ml) identified AD subjects with accuracy of 90%, with 78% positive predictive value (PPV), 97% negative predictive value (NPV), 93% sensitivity, 88% specificity compared favorably with p-tau T181 ELISA  (52 pg/ml) showing 78% accuracy, 58% PPV, 98% NPV, 71% specificity; 97% sensitivity. The assay distinguished AD patients from age-matched healthy subjects (cut-off 163 pg/ml, sensitivity 98%, specificity 93%) similarly to p-tau T181 ELISA (cut-off 60 pg/ml, 96% sensitivity and 86% specificity). In AD patients, we found a strong ...