UBIQUITIN-REACTIVE AXONS HAVE A WIDESPREAD DISTRIBUTION AND ARE UNRELATED TO PRION PROTEIN PLAQUES IN CREUTZFELDT-JAKOB DISEASE

The amyloid plaques of Alzheimer disease (AD) are surrounded by dystrophic axons that contain ubiquitinated dense bodies. To investigate whether deposits of other types of amyloid cause axonal degeneration we studied 5 cases of Creutzfeldt-Jakob disease (CJD) with immunocytochemical methods using ubiquitin and prion protein (PrP) antisera. One of these cases contained PrP plaques in the cerebellum. In all cases dystrophic axons, which contain ubiquitinated dense bodies, were observed in neocortical and cerebellar grey matter, in absence of PrP-reactive amyloid deposits. Only a minority of PrP plaques present in the cerebellum was associated with ubiquitin positive neurites. The results indicate that, unlike in AD, the occurrence of ubiquitinated dystrophic axons is independent from amyloid deposition in CJD and is likely to be a primary phenomenon.