Treatment of AIDS-associated Kaposi's sarcoma with recombinant alpha interferon

Treatment with recombinant alpha-interferon of chronic hepatitis C in anti-HIV-positive patients

A pilot study of chronic hepatitis C treatment was conducted in 14 patients (13 had chronic active hepatitis and 1 had liver cirrhosis). All patients were asymptomatic for the human immunodeficiency virus (HIV) type 1 (mean CD4 count of 584 +/- 283 cells/mm3). Patients received 9 MU rIFN-alpha 2A per day for three months. After this, patients received 9 MU three times weekly for three months, 6 MU for another three months on the same protocol, and finally 3 MU again three times weekly for the last three months. After the first month of ALT treatment in 9 patients (64%) returned to normal; a significant decrease in ALT levels was observed with respect to the pretreatment values (mean of 42 IU/l, range 15-75 vs 152 IU/l, range 69-355; P < 0.01). Of the 9 patients who completed the treatment period, 5 had a complete response, and 4 of these 5 continued with normal ALT values during follow-up (sustained response) while the other patient relapsed within one month after cessation of therapy. The remaining 4 patients were non-responders (including one case with a break-through of the response). HCV-RNA was not detectable in 3 of the 5 responders at the end of therapy while during follow-up viral RNA became undetectable in the other 2 patients. 2/4 non-responder patients had detectable HCV-RNA during follow-up. Liver histology improved in all the patients. No changes were observed in the immunological status or HIV infection.

Intralesional human leukocyte interferon treatment alone or associated with IL-2 in non-AIDS related Kaposi's sarcoma

Patients with classical European Kaposi's sarcoma were treated by intra- and peritumoral injections of human alpha leukocyte interferon (IFN) (12 cases) or, alternatively, with IFN and naturally synthesized IL-2 (8 cases). All the patients were HIV negative with tumors which had been present for at least six months. In each patient, one tumor received 1 ml (50,000 IU) IFN alone or alternatively associated with 1 ml IL-2 twice a week for 4-6 weeks; another nodule situated 10-12 cm away was considered as a control and remained uninjected. The clinical follow-up revealed that, in the same patient in the same anatomical area, the treated nodule was cured in all the investigated cases; the untreated one was not. These data strongly suggest that IFN is the factor responsible for the involution and final cure of these Kaposi tumors treated by perilesional inoculations. Association with IL-2 (and certainly also other interleukins) increases the beneficial clinical activation of the tumor involution. Histological examination showed that important histopathological changes occur in the treated nodules: complete disappearance of the Kaposi's aspect, fibrosclerous modifications progressively replacing the fibroblasts characteristic of Kaposi's sarcoma, abundant infiltrations of leukocytes, especially lymphocytes and necrotic patches, often with hemorrhagic centers. IL-2 association seems to especially induce this last type of histological phenomenon.

The use of interferon-alpha in virus infections

The interferons (IFN) act too slowly to arrest acute viral infections, but interferon-alpha (IFN alpha) preparations have proved useful in some chronic infections and will clearly be used increasingly in these in the future. In the preparations derived from human leucocytes or cultured B lymphoblastoid cells, which are in routine clinical use, mixtures of a number of distinct subtypes of human IFN alpha have been identified. There are also 3 slightly different versions of the same single subtype, IFN alpha-2, made by recombinant DNA procedures in bacteria. IFN alpha preparations are injected intramuscularly or subcutaneously. Dose-related side effects are common but usually tolerable, but prolonged treatment may cause increasing fatigue and depression. Some patients form neutralising antibodies which block the effects of the IFN; these appear to be relatively more common after recombinant IFN alpha-2 than after IFN derived from human cells. Given intranasally, IFN alpha can prevent a subsequent experimental rhinovirus infection, or the spread of natural colds within a family. Repeated administration progressively damages the nasal mucosa, so that long term prophylaxis is not possible. IFN alpha has proved useful in patients with papillomavirus warts of the larynx, ano-genital region (condyloma acuminata) and skin (common warts). Treatment regimens remain to be optimised and are likely to include surgery or other treatments. IFN alpha and zidovudine (azidothymidine) synergistically inhibit the growth of HIV in vitro, and combination are on trial in patients with early AIDS. Very large doses of IFN alpha are effective against Kaposi's sarcoma in some AIDS patients. In chronic hepatitis B, continuing virus replication may lead to cirrhosis or primary liver cancer. Earlier clinical trials with IFN alpha gave inconclusive results, but recent large studies have confirmed that 25 to 40% of patients obtain benefit; this probably results from both the antiviral and the immunomodulatory effects of IFN alpha. In patients with chronic hepatitis C, the biochemical markers usually improve rapidly during IFN alpha administration, but relapse if treatment is stopped after only a few months; to increase the chances of sustained cure, the treatment period is now being prolonged.