Although Alzheimer disease (AD) remains a clinical diagnosis, biomarkers are in use to support the diagnosis. Three cerebrospinal biomarkers, amyloid-ß (Aß), total tau (T-tau), and phospho tau (P-tau), reflect neuropathologic changes observed in AD patients.
The aim of this study was to explore the performance of the cerebrospinal fluid biomarkers used in a memory clinic setting.
We included 205 patients who had been through a standardized examination including lumbar puncture. Diagnoses were made blind to the results of the spinal fluid analyses.
By combining low Aß and high T-tau or P-tau values, the sensitivity was 31.9% and the specificity was 92.5% when comparing patients with AD with other patients. In receiver operating characteristic analyses, the AUC for the Aß was 0.78 (SE=0.04; 95% CI, 0.7-0.85), for T-tau 0.80 (SE=0.03; 95% CI, 0.73-0.86), and for P-tau 0.76 (SE=0.04; 95% CI, 0.69-0.83). A significant difference was found between the sexes, with higher values of Aß among younger men (under 65 y of age) with AD [799.8 (SD=317.2) vs. 558.9 (SD=123.5) for women, P-value=0.003].
The present study found a lower performance of the biomarkers than reported previously.