[Inactivation of viruses in Factor XIII concentrate by pasteurization]

The use of a pasteurization step (heating in solution to 60 degrees C for 10 h) makes it possible to inactivate viruses, thus increasing the safety of the preparations. Using Factor XIII concentrate solution, it can be shown that hepatitis B virus and 10 other virus species are inactivated. Pasteurized Factor XIII was produced from starting material containing a total of 10(5.7) CID50 hepatitis-B virus (10(3.5) CID50/ml; CID = chimpanzee infectious dose). This Factor XIII preparation was injected in 4 chimpanzees; they remained healthy over an observation period of 37 weeks, whereas the 2 chimpanzees that received nonheated starting material developed hepatitis B. Furthermore, Rous-sarcoma, Epstein-Barr, cytomegalo, herpes simplex, measles, and rubella virus added to Factor XIII solution are inactivated by pasteurization within 2 h, mumps virus within 8 h, and adeno, polio, and vaccinia virus within 10 h. Pasteurizing of clotting factor preparations during the manufacturing process is a suitable for inactivating viruses and thereby increasing the safety of the preparations.