Immunohistochemical identification and cross reactions of amyloid fibril proteins in senile heart and amyloid in familial polyneuropathy. Lack of reactivity with cerebral amyloid in Alzheimer's disease.

Amyloid fibril proteins in senile cardiac amyloid (ASc1), in familial amyloid polyneuropathy (AF), in congophilic angiopathy, and in Alzheimer's disease were investigated in tissue sections by the indirect immunoperoxidase method using antisera against ASc1, AF, and serum prealbumin (PA). Control antisera were tested against amyloid fibril proteins of the AA- (serum amyloid A-derived), A lambda-, and A kappa-(immunoglobulin light chain-derived)amyloid types. Senile cardiac amyloid was specifically identified in tissue sections with antisera against ASc1, AF, and PA, but not with anti-AA, -A lambda, and -A kappa, thus showing cross-reactivity of ASc1 and AF with each other and with PA, but antigenic differences to the other amyloid types. Likewise, amyloid in AF syndromes, including the Japanese, the German, and the Portuguese types, were stained with anti-AF, anti-ASc1, and anti-PA, but not with the antisera against AA, A lambda, A kappa, again showing common antigenic determinants of AF and ASc1 and PA. This is in agreement with chemical and immunochemical data obtained by others. Cerebral amyloids in microangiopathy and in Alzheimer's disease have also been investigated with these antisera and no reaction was found. The cerebral amyloids, therefore, would appear to be antigenically different from ASc1, AF, AA, A lambda, and A kappa types of amyloid.