[Current status of interferon therapy]

Abstract

Interferons (IFN) are potent antiviral, cytostatic-cytotoxic and immunomodulatory agents. Although gene technology has made available an unlimited supply of all different kinds and types of IFN, their basic modes of action have not been clarified up to now. The therapeutic effects proven differ gradually between the individual disease entities. They comprise prophylaxis, prevention of recurrences and direct therapeutic effect, either of reducing the actual disease symptoms, or of inducing a complete recovery. For the following viral diseases a positive therapeutic effect has been shown: infections by herpes-viruses (herpes simplex keratitis , herpes zoster, herpes simplex), cytomegalovirus infections, chronic-hepatitis B virus infection, acute respiratory virus infections by rhino-, corona- and influenza viruses. Especially for the group of virus-associated tumors and papillomas, IFN is considered to be therapeutically effective. IFN has been accepted to be the first line treatment for laryngeal papillomatosis. In condylomata acuminata too, IFN is a potent therapeutic agent. Moreover, IFN represents the most effective therapeutic modality for Kaposi's sarcoma in patient with AIDS. Hairy cell leukemia, malignant lymphoma, multiple myeloma, melanoma and hypernephroma are the malignancies, for which a therapeutic effect of IFN could be proven. Furthermore, IFN is considered to be the therapy of first choice for hairy cell leukemias. Although there are some signs, that IFN could be a potent agent for adjuvant therapy, this question can not be answered - not even on principle - because of lacking sufficient data so far. Up to date, the therapeutic efficacy of IFN seems to be established only for hairy cell leukemia, laryngeal papillomatosis, Kaposi's sarcoma in patients with AIDS and partly for condylomata acuminata. For all other indications, first of all, sufficient phase-II-study data will have to be evaluated, before prospectively controlled studies, comparing the IFN treatment results with placebo and standard therapy results, can be initiated for the individual disease entities. Then, it will be possible to assess the therapeutic efficacy of IFN. Already now, IFN represent a valuable enrichment of the therapeutic modalities for malignancies and viral diseases.