Cerebrospinal fluid A beta(42), tau, and F-2-isoprostane concentrations inpatients with Alzheimer disease, other dementias, and in age-matched controls

Objective.-To test the hypothesis that quantification of cerebrospinal flui d (CSF) F-2-isoprostanes (F-2-IsoPs), in vivo biomarkers of free radical da mage, along with CSF A beta (42) and tau levels improves laboratory diagnos tic 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 A beta (42) an d tau were determined by a commercially available test (Athena Diagnostics, Worcester, Mass). Cerebrospinal fluid F-2-IsoP levels were quantified by g as chromatography/mass spectrometry. Results.-Individuals were classified as AD or non-AD by a published method using CSF A beta (42) and tau levels (95% sensitivity, 50% specificity), by CSF F-2-IsoP levels greater than 25 pg/mL and A beta (42) concentrations l ess than 1125 pg/ mt (90% sensitivity, 83% specificity), and by combined an alysis using CSF F-2-IsoP, A beta (42) and tau levels (84% sensitivity, 89% specificity). Conclusion.-Cerebrospinal fluid F-2-IsoP quantification may enhance the acc uracy of the laboratory diagnosis of AD.