Senile aortic amyloid. A third distinctive type of age-related cardiovascular amyloid

Aortic tissues from 22 elderly patients were analyzed by Congo red staining for amyloid deposits. All samples contained amyloid, which was resistant to the potassium permanganate reaction. Tryptophan was present in all amyloid deposits. The amyloid failed to react with antiserums to amyloid fibril protein ASc1 or human prealbumin, proteins previous demonstrated in generalized senile cardiac amyloid. It also differed from age-related isolated atrial amyloid, which has been shown to lack tryptophan. Deposits did not react with antiserums specific for amyloid fibril proteins of the A lambda IV, A lambda VI, AA, or AEt types. These results indicate that senile aortic amyloid is distinct from amyloid present in primary and secondary amyloidosis and appears to represent a third form of cardiovascular amyloid associated with the aging process.