Human leukocyte interferon treatment associated with IL-2 in the non-AIDS related Kaposi's sarcoma.

Patients with classical European Kaposi's sarcoma have been treated by intra- and peritumoral injections of human alpha-leukocyte interferon (IFN) (12 cases) or alternatively with IFN and naturally synthetized IL-2 (8 cases). All the patients were HIV negative their tumour appearing at least six months before. In each patient one tumour received 1 ml (50,000 IU) IFM alone or associated, alternatively with 1 ml IL-2, twice a week during 4-6 weeks, whereas another nodule situated 8-10 cm apart was considered as 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 while the untreated nodule was not. These data undoubtedly prove that IFN is the responsible factor for the involution and final cure of the Kaposi tumours treated by perilesional inoculations. Association with IL-2 (and certainly also other interleukins) increases the beneficial clinical effect activating the tumour involution. The histological examination showed that important histopathological changes occur in the treated nodules, i.e., complete disappearance of the Kaposi's aspect; fibrosclerous modifications progressively replacing the abundant fibroblastic cells characteristic of Kaposi's tumour; abundant infiltrations of leukocytes especially lymphocytes; necrotic patches often appearing along with hemorrhagic centers. IL-2 association seems to frequently induce especially this last type of histological phenomena.