STRATEGY FOR PRECLINICAL EVALUATION OF FACTOR-VIII CONCENTRATES

A series of methods and assay systems was designed, using both mouse m onoclonal antibodies and purified human polyclonal antibodies, by whic h alterations in the antigenic properties, and potentially therefore i n the immunogenic properties, of FVIII concentrates could be identifie d. Those methods could be applied to the pre-clinical evaluation of FV III concentrates. It has become evident that very subtle alterations i n FVIII can have dramatic effects on its antigenicity and immunogenici ty and it is suggested that an analysis of FVIII preparations, using r eagents such as mouse monoclonal antibodies, should be carried out as a pre-clinical evaluation. It is also thought that any haemophiliac pa tient is at risk of developing anti-FVIII antibodies, even though he h ad been considered as tolerant to the infusion of FVIII. The diversity of FVIII concentrates now available on the market has multiplied the chances of encountering a product that would give an immune response i n some patients and this further stresses the need for a careful check of FVIII concentrates.