Mirror Image of the Amyloid-β Species in Cerebrospinal Fluid and Cerebral Amyloid in Alzheimer's Disease

Alzheimer's disease (AD) is characterized by amyloid-beta (A beta) accumulation in brain that is paralleled by A beta(1-42) reduction in cerebrospinal fluid (CSF). We analyzed the pattern of A beta peptides, including the N- and C-terminal truncated fragments, in brain and CSF from two familial and one sporadic AD cases. We found that (i) each patient is characterized by a distinct A beta profile in CSF and brain deposits and (ii) the CSF A beta pattern mirrors the A beta profile of cerebral amyloid. These results suggest the existence of different molecular AD subtypes which can be recognized by CSF analysis, enabling patient stratification.