ASSAYS FOR ANTIBODIES TO HUMAN INTERFERON-ALPHA - THE NEED FOR STANDARDIZATION

Since the first reported occurrence of anti-interferon (IFN) antibodie s in 1981, the reported incidence of antibody production has differed enormously, In some clinical trials of human IFN preparations, no pati ents developed antibodies, whereas other studies reported an incidence of more than 80%. In patients with hepatitis C, the reported incidenc e varies from 7% to 61%, One of the factors contributing to the variab ility of the results is the lack of a standard assay system to measure antibodies to IFNs, In 1994, a Concerted Action funded by the Europea n Commission started to coordinate studies into the immunogenicity of recombinant DNA-derived pharmaceuticals, These studies aimed to examin e whether antibodies could interfere with the efficacy of treatment an d also studied the long-term effects on cytokines produced by the pati ents themselves, Only when a well-calibrated and standardized assay is available, however, will it be possible to define the biologically re levant titer of antibody. Assays for both binding and neutralizing ant ibodies are discussed here.