A comparative trial of recombinant interferon alpha 2A versus alpha 2 beta on myelosuppression in healthy adult volunteers

BACKGROUND/AIMS: Recombinant interferon (r-IFN) is an antiviral agent used to treat patients with chronic viral hepatitis patients. Unfortunately, the use is often limited due to its myelosuppressive properties. Currently, there are two forms of r-IFN commercially available: r-IFN alpha-2a and rIFN alpha-2b. Although both are thought to be equally effective, a comparative study of their myelosuppressive properties has not been undertaken. MATERIALS AND METHODS: In the present study, three groups of healthy adult volunteers (n = 6/group) were randomized to receive a two week course of either r-IFN alpha-2a or r-IFN alpha-2b (5 million units, subcutaneously, thrice weekly) or no treatment. All subjects were then followed for an additional two week post treatment; observation period. RESULTS: The results of the study revealed that both forms of r-IFN alpha caused a significant and similar decrease in white blood cell counts (maximum declines of 37.9 +/- 6.8% for alpha-2a and 39.5 +/- 6.0% for alpha-2b at day 4) and platelet counts (maximum declines of 19.5 +/- 8.6% for alpha-2a and 20.2 +/- 8.4% for alpha-2b at day 2) from baseline values. Following discontinuation of therapy, white blood cell and platelet counts returned to pretreatment levels. Hemoglobin levels remained unchanged throughout the study period. CONCLUSION: The results of this study indicate that r-IFN alpha causes a prompt and significant decrease in white blood cell and platelet counts. However, no differences exist between r-IFN alpha-2a and r-IFN alpha-2b in terms of their myelosuppressive properties in humans.