Cerebrospinal fluid abeta42, tau, and f2-isoprostane concentrations in patients with Alzheimer disease, other dementias, and in age-matched controls.

Objective: To test the hypothesis that quantification of cerebrospinal fluid (CSF) F(2)-isoprostanes (F(2)-IsoPs), in vivo biomarkers of free radical damage, along with CSF Abeta(42) 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 Abeta(42) and tau were determined by a commercially available test (Athena Diagnostics, Worcester, Mass). Cerebrospinal fluid F(2)-IsoP levels were quantified by gas chromatography/mass spectrometry.
Results: Individuals were classified as AD or non-AD by a published method using CSF Abeta(42) and tau levels (95% sensitivity, 50% specificity), by CSF F(2)-IsoP levels greater than 25 pg/mL and Abeta(42) concentrations less than 1125 pg/mL (90% sensitivity, 83% specificity), and by combined analysis using CSF F(2)-IsoP, Abeta(42), and tau levels (84% sensitivity, 89% specificity).
Conclusion: Cerebrospinal fluid F(2)-IsoP quantification may enhance the accuracy of the laboratory diagnosis of AD.