Neuropathological analysis of pathological forms of astroglia in Wilson's disease.

A neuropathological study of Alzheimer type I (Alz I) and Alzheimer type II (Alz II) as well as Opalski (Opl) cells was performed serially on brain tissue from nine autopsied Wilson's disease (WD) cases. Conventional staining methods (Kluver-Barrera, HE, PAS) and immunocytochemical techniques (anti-GFAP and anti-Metallothionein-MT) were used. On conventional staining, each of the studied abnormal cell types retained common morphological characteristics of astroglia, and concurrently demonstrated its own distinctive features, specific only for a given cell type. Anti-GFAP staining revealed positive immunoreactivity of Alz I and Opl cells, and its absence in Alz II cells. On anti-MT staining both the cytoplasm and nucleus of Alz I and Opl cells showed positivity whereas in Alz II cells the cytoplasm was positive in contrast to the negative nucleus. The results of our study confirm the hypothesis of the astroglial origin of all three types of cells. The lack of immunoreactivity for GFAP and similar immunocytochemical staining patterns for MT in Alz II cells and protoplasmic astrocytes may suggest that Alz II cells originate from the protoplasmic type of astroglia. The fact that Alz I and Opl cells resemble fibrous astrocytes in their immunoreactive positivity for GFAP may lead to a supposition that they originate from the fibrous type of astroglia. MT-positive expression by the three abnormal cell types suggests that they may be involved in the process of copper detoxification in WD.