Radioiodinated autologous fibrinogen: a rapid method of preparation for clinical use

A method of producing radiolabeled autologous fibrinogen (RAF) was developed based on the deactivation of prothrombin and plasminogen rather than their removal. RAF can be compounded in less than 1 hr utilizing a kit that provides the necessary reagents and materials pretested for purity, sterility, and apyrogenicity. The method combines an adaptation of the fibrinogen separation technique of Roberts, et al with the Helmkamp, et al modification of the iodine monochloride labeling procedure. The relative merits of the different methods of iodinating fibrinogen are discussed in Chapter 51. Since the literature contains reports showing the loss of biological activity as a consequence of both the iodine-to-protein ratio as well as the type of oxidizing agent used to create the electrophilic iodine atom, the biological activity of RAF was examined using both physicochemical and biological methods. In vitro, animal, and clinical studies show this rapid procedure produces biologically active radioiodinated fibrinogen. There is minimal denaturation during labeling and the risk of serum hepatitis transmission is eliminated