Cerebrospinal Fluid Aβ42, Tau, and F2-Isoprostane Concentrations in Patients With Alzheimer Disease, Other Dementias, and in Age-Matched Controls

Abstract

Abstract Objective.—To test the hypothesis that quantification of cerebrospinal fluid (CSF) F2-isoprostanes (F2-IsoPs), in vivo biomarkers of free radical damage, along with CSF Aβ42 and tau levels improves laboratory diagnostic accuracy for Alzheimer disease (AD). Participants.—Patients with probable AD (n = 19), dementias other than AD (n = 8), and age-matched controls (n = 10). Main Outcome Measures.—Cerebrospinal fluid concentrations of Aβ42 and tau were determined by a commercially available test (Athena Diagnostics, Worcester, Mass). Cerebrospinal fluid F2-IsoP levels were quantified by gas chromatography/mass spectrometry. Results.—Individuals were classified as AD or non-AD by a published method using CSF Aβ42 and tau levels (95% sensitivity, 50% specificity), by CSF F2-IsoP levels greater than 25 pg/mL and Aβ42 concentrations less than 1125 pg/mL (90% sensitivity, 83% specificity), and by combined analysis using CSF F2-IsoP, Aβ42, and tau levels (84% sensitivity, 89% specificity). Conclusion.—Cerebrospinal fluid F2-IsoP quantification may enhance the accuracy of the laboratory diagnosis of AD.