[Update on the use of interferons in clinical practice].

Discovered by Isaac and Lindemann as a substance able to induce a biological interference among viruses and host cells, interferon appeared to include three main antigenic classes: alpha, beta and gamma. There is a large variety of actions exhibited by different types of interferon and among them it is possible to distinguish an antiviral, antineoplastic, immunomodulatory or hormonal activity. Many years ago, the antiviral action seemed to be relative to some cellular membrane disorders, but later other mechanisms were stressed. Among them, it is worth describing the transcription and transduction of antiviral proteins like the oligoadenilsinthetase and proteinphosphokinase, able to cause the viral RNA breackage. The antineoplastic action is exerted by direct and indirect mechanisms. Direct mechanisms include an antiproliferative activity and the induction to cellular differentiation whereas the indirect ones involve the enhancement on tumor cell surfaces of some tumor associated antigens included in the I class of MHC system. The immunomodulatory action is exerted by the stimulation of macrophages, T cells and Killer cells cytotoxic activity. The list of viral diseases sensitive to interferon treatment includes condiloma acuminata, herpes zoster, chronic B and C hepatitis and Kaposi sarcoma AIDS-related. High proportions of overall response rate were observed among interferon treated patients with condiloma acuminata (80-100%). The use of interferon in the treatment of herpes zoster achieved good results regarding a shorter duration of the time spent to induce the chest pains and cutaneous symptoms disappearance when compared with that relative to other antiviral drugs. Results obtained in the treatment of chronic B and C hepatitis regard the disappearance of viral replication serological markers and the improvement of histological and enzymatic pattern. The effectiveness of interferon in the therapy of Kaposi sarcoma is demonstrated by the reduction of cutaneous symptoms and recurrent infectious diseases incidence. The use of interferon in treatment of solid tumors seems to play secondary role and, at any rate, to be adjuvant to chemotherapy. The administration of beta interferon as therapy of breast cancer seems to increase the estrogens and progesterone concentration in the neoplastic tissue and so it aims to improve the sensitivity to the tamoxifen treatment. The addition of interferon alpha both to 5-FU and cis-platinum seems to improve the proportion of overall response rate respectively in the treatment of colon cancer and head and neck cancer.(ABSTRACT TRUNCATED AT 400 WORDS)