RESUMEN
OBJECTIVES: Cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are well-established in research settings, but their use in routine clinical practice remains a largely unexploited potential. Here, we examined the relationship between CSF biomarkers, measured by a fully automated immunoassay platform, and brain ß-amyloid (Aß) deposition status confirmed by amyloid positron emission tomography (PET). METHODS: One hundred ninety-nine CSF samples from clinically diagnosed AD patients enrolled in a clinical study and who underwent amyloid PET were used for the measurement of CSF biomarkers Aß 1-40 (Aß40), Aß 1-42 (Aß42), total tau (t-Tau), and phosphorylated tau-181 (p-Tau181) using the LUMIPULSE system. These biomarkers and their combinations were compared to amyloid PET classification (negative or positive) using visual read assessments. Several combinations were also analyzed with a multivariable logistic regression model. RESULTS: Aß42, t-Tau, and p-Tau181, and the ratios of Aß42 with other biomarkers had a good diagnostic agreement with amyloid PET imaging. The multivariable logistic regression analysis showed that amyloid PET status was associated with Aß40 and Aß42, but other factors, such as MMSE, sex, t-Tau, and p-Tau181, did not significantly add information to the model. CONCLUSIONS: CSF biomarkers measured with the LUMIPULSE system showed good agreement with amyloid PET imaging. The ratio of Aß42 with the other analyzed biomarkers showed a higher correlation with amyloid PET than Aß42 alone, suggesting that the combinations of biomarkers could be useful in the diagnostic assessment in clinical research and potentially in routine clinical practice.