＜Symposium IV＞Plasma antibodies to Aβ40 and Aβ42 in patients with Alzheimer's disease and normal controls

概要

論文の詳細を見る
Antibodies to amyloid β protein（ Aβ） are present naturally or after Aß vaccine therapy in human plasma.To clarify their clinical role, we examined plasma samples from 113 patients with Alzheimer’s disease（ AD） and 205normal controls using the tissue amyloid plaque immunoreactivity （TAPIR） assay. A high positive rate of TAPIRwas revealed in AD （45%） and age-matched controls （41%）, however, no signifi cance was observed. No signifi cantdifference was observed in the MMS score or disease duration between TAPIR-positive and negative samples.TAPIR-positive plasma reacted with the Aß40 monomer and dimer, and the Aβ42 monomer weakly, but not with theAβ42 dimer. TAPIR was even detected in samples from young normal subjects and young Tg2576 transgenic mice.Although the Aβ40 level and Aβ40/42 ratio increased, and Aβ42 was significantly decreased in plasma from ADgroups when compared to controls, no signifi cant correlations were revealed between plasma Aß levels and TAPIRgrading. Thus an immune response to Aβ40 and immune tolerance to Aβ42 occurred naturally in humans without aclose relationship to the Aβ burden in the brain. Clarifi cation of the mechanism of the immune response to Aβ42 isnecessary for realization of an immunotherapy for AD.