Long term effects of amyloid enhancing factor: Clinical and experimental implications

Objective: To study the long term effects of amyloid enhancing factor (AEF). Methods: AEF, prepared from pre-amyloidotic mouse spleens, was injected intravenously into Swiss and ICR mice. This was followed by 3 daily subcutaneous injections of AgNO₃, given at increasing time intervals from the administration of AEF. The mice were sacrificed on day 6 from the first AgNO₃ injection, and the mean grade of amyloid deposition in the spleens was estimated using the crush and smear technique. Results: AEF was found to have a prolonged enhancing effect, retaining its activity for more than 3 months after its administration in both mouse strains. Conclusions: Experimental animals may develop amyloidosis long time after exposure to AEF. This finding may underlie the acute reoccurrence of amyloidosis sometimes observed in patients and mice long after its resolution.