Immunogenicity of amyloid.

Human amyloid appears to contain two immunogenic components, the P (plasma) component and the F (fibril) component. Antisera to P component react with both autologous and homologous antigens by immunodiffusion and fluorescent antibody techniques; antisera to F component react with autologous antigens by immunodiffusion and fluorescent antibody techniques, but react with homologous antigens only by the fluorescent antibody method. Antisera to both P component and F component fail to react with non-amyloid human tissues as well as amyloid deposits in guinea-pig tissues. These results point to heterogeneity in the antigenic determinants of human amyloid and possibly greater inter-species heterogeneity of amyloid.