Antigenic properties of Bioplast

The influence of heat treatment (at 150 +/- 2 degrees C for 2 hours) on the antigenicity of human Bioplast fibrin powder and human fibrin Bioplast plates was tested in an experimental study. Untreated and heat-treated fibrin powder with incomplete Freund's adjuvant was subcutaneously injected in rabbits. In addition, untreated and heat-treated plates, to which incomplete Freund's adjuvant was added, were subcutaneously implanted. A booster dose was given 8 weeks after the start of the experiment. Blood samples were collected up to 4 weeks after the second injection or implantation, and the sera were tested for precipitating antibodies by the double diffusion technique (OUCHTERLONY'S method). Unlike previous investigators, we found antibodies in sera from rabbits injected or implanted with heat-treated Bioplast products. Thus, the claim that the antigenic properties of all kinds of fibrin can be fully eliminated by heat treatment does not appear to be tenable. In order to avoid the risk of sensitization in man, it is probably advisable to use only human fibrin for the production of Bioplast fibrin powder and Fibrin Bioplast plates for clinical use in human beings.