FIGURE 4.

p217+tau fragmentation in blood may be similar extent to that in cerebrospinal fluid (CSF). A, Schematic showing epitopes of the Abs used in the p217+tau “short” (PT3xPT82) and p217+tau “long” (PT3xHT43) assays. A set of matching (B) CSF, (C) serum, and (D) plasma from 18 subjects with mild‐to‐moderate dementia was measured with the p217+tau “short” and p217+tau “long” assays. In each sample type the p217+tau “short” assay reported ≈2x the concentration of the p217+tau “long” assay, indicating the fragmentation level between these epitopes may be similar in these three sample types