Interferons

nterferons, naturally occuring glycoproteins with molecular weights of approximately 20,000 daltons, possess antiviral, antiproliferative, and immune-stimulating properties. They are classified into 3 antigenically distinct forms that are derived from different cell types. Alpha (or) interferons are derived from leukocytes, beta ([3) interferons from fibroblasts, and gamma (/) interferons from T lymphocytes. They have been approved for use in the treatment of condylomata acuminata, hepatitis B and C, and hairy-cell leukemia. While naturally occurring ot interferons can be obtained from pooled leukocytes derived from whole blood and then stimulated to produce interferon [or-n3 Alferon (Purdue Frederick Company, Norwalk, CT); or-N1 WellferonTM (Pacific Pharmacy, San Francisco, CA)], they can also be produced through recombinant DNA technology [o-2a RoferonT= (Roche Laboratories, Nutley, NJ); ot-2b Intron A (Schering Corporation, Kenilworth, NJ)]. ot-2a and ot-2b differ by only amino acid in position -23. The natural interferons are really mixtures of 14 or more types, while the recombinant types are pure quantities of a single species of interferon.