Immunohistochemical analysis of β-amyloid and AT8 in late-onset Alzheimer' s disease / 中华神经科杂志

ABSTRACT

Objective To study the neuropathological characteristics of late-onset Alzheimer' s disease (LOAD) in Chinese people, to ensure correct diagnosis of LOAD.Methods Choosing cerebral cortex of temporal layer of 8 cases of LOAD and 5 cases of age-matched normal control group by autopsy.Histopathologlc diagnosis was established in all these 13 cases.Cerebral cortex were taken from temporal layer in 13-101 hours after death and were fixed with 40 g/L paraformaldehyde, followed by paraffin-embedding and serial sectioning with 6 μm thickness.Brain tissue was analyzed neuropatholically by using immunohistochemical staining for β-amyloid (Aβ) and AT8 on these cases.Positive distribution of temporal layer was observed under light microscope.Results The results of immunohistochemical stainings of Aβ and AT8 were positive in all of LOAD.Aβ immunoreactant located in the cerebral cortex.The diffuse plaques, primitive plaques and burn-out plaques of senile plaques were displayed clearly by immunohistochcmical stainings of Aβ.AT8 immunoreactants showed neurofibrillary tangles, neuropil thread and senile plaques in nerve cell of cerebral cortex in different degree respectively.The positive rate Aβ and AT8 were both 8/8 by semiquantitative analysis in AD group.As the normal aging control group, which was 0 and 1/5 respectively.There was significant difference of the positive rate Aβ and AT8 in two groups(χ2 = 13.000,P=0.001; χ2=9.244,P=0.007).Conclusions Sensitive immunnhistochemical technique was significant to display senile plaques and neurofibrillary tangles.The findings demonstrate that immunohistochemistry staining of Aβ and AT8 can display senile plaques and neurofibrillary tangles clearly.The connection of the 2 different methods might improve diagnose accordance rate of AD.