Fig. 4: CSF fibril length as a potential biomarker of AD pathology.
From: Protein fibril length in cerebrospinal fluid is increased in Alzheimer’s disease
Scatterplots of the individual mean fibril length in CSF plotted against the CSF Amyloid 42/40 ratio (a) and CSF p-tau levels (b) as well as the respective Pearson regression results. c, d Depict the ROC analyses and diagnostic performance measures of CSF fibril length for detecting Amyloid-pathology as determined by a CSF Amyloid 42/40 ratio < 0.068 (c), respectively Tau pathology defined as CSF p-tau levels >59 ng/l (d). The respective cutoffs were set at the highest Youden-index. The CSF fibril length was significantly, inversely correlated with the CSF Amyloid 42/40 ratio (r = −0.62, p > 0.001, see a) and positively correlated with CSF p-tau (r = 0.45, p > 0.001, see b). When applying a fibril length cutoff of ≥0.625 µm (horizontal red line in a) the Amyloid pathology could be determined with an accuracy of 94% (sensitivity: 0.95, specificity: 0.92, see c). Regarding Tau-pathology, a cut-off of ≥1.15 µm (highest Youden index) predicted Tau status with an accuracy of 82% (sensitivity: 0.82, specificity: 0.81, see d). (prev: prevalence, acc accuracy, sens sensitivity, spec specificity, AUC area under the curve).
