ABSTRACT
Interferon was described by Isaacs and Lindenman in 1957 and given its name because of its ability to interfere with viral reproduction in tissue culture. Clinical studies of interferon in cancer and viral infections were impeded by scarce supplies and the enormous expense of production. Interferon titers are expressed as reciprocals, with the dilutions producing a 50% reduction of virus cytopathic effect. Despite these problems, a few trials were begun in the 1960s and clinical activity continued at an accelerated pace in the 1970s with buffy coat derived human leukocyte interferon produced in the laboratory of Dr. Kari Cantell in Finland. Serum interferon levels were closely monitored during the multiple dose studies as well. Hybridoma-produced monoclonal antibodies with the ability to purify interferon proteins to homogeneity were developed. Availability of an unlimited amount of pure leukocyte interferon obtained through genetic engineering allowed for the first time systematic evaluation of this protein in a sufficient number of patients.
