Blood Amyloid-β Oligomerization as a Biomarker of Alzheimer’s Disease: A Blinded Validation Study

BACKGROUND: Oligomeric amyloid-beta (Abeta) is one of the major contributors to the pathomechanism of Alzheimer's disease (AD); Abeta oligomerization in plasma can be measured using a Multimer Detection System-Oligomeric Abeta (MDS-OAbeta) after incubation with spiked synthetic Abeta. OBJECTIVE: We evaluated the clinical sensitivity and specificity of the MDS-OAbeta values for prediction of AD. METHODS: The MDS-OAbeta values measured using inBlood OAbeta test in heparin-treated plasma samples from 52 AD patients in comparison with 52 community-based subjects with normal cognition (NC). The inclusion criterion was proposed by the NINCDS-ADRDA and additionally required at least 6 months of follow-up from the initial clinical diagnosis in the course of AD. RESULTS: The MDS-OAbeta values were 1.43+/-0.30 ng/ml in AD and 0.45+/-0.19 (p < 0.001) in NC, respectively. Using a cut-off value of 0.78 ng/ml, the results revealed 100% sensitivity and 92.31% specificity. CONCLUSION: MDS-OAbeta to measure plasma Abeta oligomerization is a valuable blood-based biomarker for clinical diagnosis of AD, with high sensitivity and specificity.