Discovery of new lesions in neurodegenerative diseases with monoclonal antibody techniques is there a non-amyloid precursor to senile plaques?

The manuscript by Schmidt et al reports that antibodies generated to paired helical filaments (AMY antibodies) unexpectedly labeled novel non-amyloid, plaque-like structures (AMYplaques) in aged and Alzheimer's disease brains. Tlieftill disclosure of the nature of these lesions awaits additional structural and biochemical studies, but at first glance there are interesting parallels between AMY plaques and recently described lesions composed ofglia and glia-associated proteoglycans in brains of aged mice. The increasing recognition of the role ofproteoglycans in paired helical filaments formation makes proteoglycans or their associated molecules attractive candidates for AMY-immunoreactive proteins. Tlie relationship of AMY plaques to age-related glial changes that some have speculated may be precursors to senile plaques remains to be determined, as is the relationship of AMY plaques to more widely recognized amyloid-containing plaques. Future studies will determine whether AMY plaques arc non-amyloid precursors to senile plaques or if they represent an independent type of structural lesion in the Alzheimer's disease brain. Ultimately, the clinical significance of AMY plaques ivill depend upon their characterization in brains of prospectively studied subjects.