Diagnostic Validity Comparison Between Criteria Based on CSF Alzheimer's Disease Biomarkers

Aim: To compare the diagnostic validity of NIA-AA criteria, for AD CSF biomarkers, with our own new criteria. Materials and Methods: Between 2008 and 2011, 170 patients with Mild Cognitive Impairment (MCI) were included. CSF levels of A beta 1-42, T-tau, P-tau181, and ratios of T-tau/A beta 1-42 and P-tau181/A beta 1-42 were analyzed. In our criteria, we considered 3 or more abnormal variables indicative of a high likelihood of MCI due to AD. Results: After a clinical follow-up of 4.5 +/- 1.2 years, 44 patients remained stable, 95 developed AD, 15 other forms of dementia, 7 died and 9 received other diagnoses. Using the NIA-AA criteria and our own criteria, the diagnostic validity of the CSF biomarkers was 58% versus 85%, specificity 84% versus 72%, PPV 82% versus 79% and NPV 61% versus 79%. Conclusion: The inclusion of the ratios in diagnostic criteria increases sensitivity and NPV for the diagnosis of MCI due to AD.