Influence of albumin content and freeze-drying on the immunogenicity of human recombinant Interferon alpha-2b in mice
Abstract
Antibodies against interferon (IFN) could explain the lack of response to treatment or the development of autoimmune processes. The albumin content and the freeze-drying process of IFN alpha formulations could be involved in the generation of such antibodies in treated patients. To study this, the immunogenicity of four formulations of human recombinant IFN alfa-2b was compared in mice. One-hundred sixty Balb/c mice were randomly and evenly distributed among the following four formulations: Heberon Alpha R, lyophilized containing 1.5 mg albumin per 3 x 106 IU of IFN, lyophilized albumin-free, or liquid albumin-free, and Reaferon-ES, lyophilized with 5 mg albumin per 3 x 106 IU of IFN. They were immunized subcutaneously with 100 000 IU of IFN alpha-2b three times a week for four weeks. Mice immunized with Reaferon-ES produced the highest serum titers of IFN alpha-2b antibodies by ELISA in the last 2 weeks, while the Heberon Alpha R liquid albumin-free formulation was the least immunogenic. Intermediate titers were obtained with the Heberon Alpha R lyophilized formulations, although they were larger for the formulation with albumin. We can conclude that albumin content and the freeze-drying process seem to have an influence on the formation of antibodies in mice.