Safety issues relating to the use of mammalian cells as hosts

There has been increasing interest over the past decade in exploring the possibility of using continuous cell lines as substrates for the production of both old and new biological products. The recent introduction of hybridoma technology to produce monoclonal antibodies, and the use of lymphoblastoid cells to produce interferon has broadened the discussion even further because both of those cell substrates are frankly tumorigenic. More recently, recombinant DNA technology has expanded beyond bacterial cells to mammalian cells, some of which may also be tumorigenic. One of the major safety concerns in biologicals produced from other than normal cells relates to the possibility that one or more of the biological characteristics of abnormal cells might be transmitted through residual DNA in the biological product to the human recipients. The assessment of risk for a given product must ultimately be based on the totality of evidence available including generic data on DNA as well as specific pieces of information on the product itself. These issues are discussed in the context of attempting to identify those data elements for the product which are essential for making an assessment of risk, plus generic information which may help to put the risk of DNA into an overall biological perspective.