Could these "rings" be similar to the amyloid rings known as "Biondi rings" seen in the choroid plexus of AD patients on autopsy?

References:
Wen GY, Wisniewski HM, Kascsak RJ. Biondi ring tangles in the choroid plexus of Alzheimer's disease and normal aging brains: a quantitative study. Brain Res. 1999 Jun 19;832(1-2):40-6. Abstract

View all comments by Joel Ross

As a coauthor of this paper, and probably the first person that had the privilege to describe these ring plaques, I want to make it very clear that Biondi ring tangles in choroidal plexus cells are intracellular features, while ring plaques in the brains of people with the Arctic APP mutation are extracellular accumulations of amyloid resembling neuritic plaques but without a core. The size of the plaques (after fixation) is around 150 micrometers in diameter, exceeding the size of any known cell in the brain. Moreover, ring plaques are negative for Congo red and thioflavin S. That is not the case for Biondi ring tangles. We very clearly illustrated in the article that the rings’ localization is in the cortex. A comprehensive neuropathology study on three different cases is ongoing, and all cases display the same type of pathology, making those plaques very unique and specific for Arctic mutation.

View all comments by Nenad Bogdanovic