Prevalence of A4 amyloid protein deposition in the chinese population determined by immunocytochemistry

Abstract

The study was performed on 203 randomly selected autopsy brains in Chinese in Hong Kong, aged 50 years or more, dying in a regional general hospital. Histological sections of parietal blocks and hippocanpal blocks were stained with H & E and congo red. Formic acid pretreated sections were immunostained with rabbit antiserum against synthetic A4 protein (kindly supplied by Prof. Masters) using avidin- biotinylated peroxidase technique. A4 protein deposits were quantitated manually using a graticule placed on the cortical ribbon and a mean plaque score (PS) was assigned. The quantity of A4 protein deposits is strikingly greater than the amount of amyloid seen by congo red polarization microscopy. The prevalence of A4 protein deposits and the mean PS rise with age. Its deposition does not correlate well with clinical diagnosis of Alzheimer's disease. Prevalence in Chinese is statistically lower than those in Australia (Masters 1988) and in U.K. (Mann 1990). NGMASTERSMANNNumber20311060Prevalence of A4 deposits≥50 yr20.2%45%51%≥65 yr23.5%55%78%Male: Female1:21:1Not Mentioned