Trace amounts of murine immunoglobulin in affinity purified leukocyte interferon alpha are not immunogenic.

Human leukocyte-derived interferon alfa-n3 (Alferon N Injection) is purified to very high specific activity over a murine immunoaffinity column specific for human interferon alpha. Trace amounts of murine immunoglobulin copurify with the interferon alfa-n3. Three populations of individuals were studied for the development of human anto-murine antibodies (HAMA), that is, normal donors, Condylomata acuminata patients receiving interferon alfa-n3, and Condylomata acuminata patients receiving placebo. High and variable endogenous levels of HAMA were observed in all three populations. The same relative increase in HAMA was seen in the placebo as in the interferon alfa-n3 treatment groups. The data demonstrate that intralesional injection of the interferon alfa-n3 did not induce the development of HAMA.