Pathology of variant Creutzfeldt-Jakob disease

Variant Creutzfeldt-Jakob disease (vCJD) is a novel prion disease in man wh ich was first described in 1996 in the UK. There is substantial evidence to indicate that vCJD represents the effects of the bovine spongiform encepha lopathy (BSE) agent in man. The neuropathology of VCJD is characterised by the florid plaque, composed of a central amyloid core with a fibrillary per iphery, surrounded by a rim of spongiform change in an intact neuropil. Uni que patterns of PrP accumulation in VCJD are revealed by immunocytochemistr y in the cerebral and cerebellar cortices, the basal ganglia, thalamus and brainstem. The neuropathology of the thalamus and midbrain is also characte rised by severe neuronal loss and gliosis. VCJD is distinct from other huma n prion diseases in that disease-associated PrP accumulates within follicul ar dendritic cells in lymphoid tissue, and consistently in peripheral senso ry ganglia. All vCJD patients so far have been methionine homozygotes at co don 129 in the PrP gene. There is no evidence to indicate that cases of BSE infection have occurred in individuals in the UK who are MV or VV at codon 129 in the PrP gene. It is conceivable that BSE incubation periods in thes e groups may be longer than in methionine homozygotes, hence the precise nu mbers of future cases of VCJD are difficult to estimate at present.