The detection of antibodies to recombinant interferon alfa-2a in human serum.

Three different procedures have been used for detecting antibodies to Roferon-A (recombinant human interferon alfa-2a, rHuIFN alpha-2a) in the serum of patients who received this interferon as part of ongoing clinical trials: an antiviral neutralization bioassay (ANB), the standard method recommended by the World Health Organization (WHO), and the more recently developed radioimmunoassay (RIA) and enzymeimmunoassay (EIA). Although the three tests are based on different principles, the correlation among them was excellent. The assays show differences in sensitivities with the ANB being the least sensitive of the three. The EIA equals the RIA in sensitivity, reproducibility, accuracy and labor and provides the advantage of safety and convenience in the use of non-radioactive materials. Therefore, the EIA has been selected as the most suitable assay for initial screening of the sera of patients receiving Roferon-A for the presence of antibodies to this interferon. EIA positive sera are then tested in the ANB to determine whether or not neutralizing activities are present.