[Interferons. Treatment of malignant hemopathies with interferons]

Interferons (INF) are glycoproteins with protean antiviral, immunomodulator, and antiproliferative actions. In Haematology, IFN-alpha is the most widely used. Diffusion into the spleen, bone marrow and liver is good. Hairy cell leukemia is probably the malignant blood disorder which responds best to IFN. At some time during their treatment, nearly 90% of the patients require IFN. Treatment initiation is indicated when pancytopenia (polynuclear neutrophils below 1 x 10(9)/L) develops or in case of a very voluminous spleen. IFN-alpha 2a, 2b and 2c are active (leukocyte IFN is used less often, as is IFN-beta; IFN-gamma is ineffective). The standard dose is 3 x 10(6) U, three times a week for 12 weeks. Smaller doses and maintenance treatment is sometimes proposed. Haematological remission occurs in almost all cases, if not a misdiagnosis must be considered (villous lymphocyte lymphoma). Relapse usually occurs at the end of treatment, but sensitivity to IFN is not altered and final survival is improved. Nearly 90% of the patients are alive at 4 years. Although IFN is active in chronic myeloid leukemia, research in this area continues. Clinical trials have reported haematologic relapse in 90% and complete cytogenetic response in 15 to 35% of the patients. The effect on Ph+ cells is not observed with classical chemotherapies. Initial dose is generally 5 x 10(6) U/m2/day. High doses are not always well tolerated, but cytogenetic response is only seen in patients in haematologic and cytopenic remission. IFN therapy improves survival over classical treatments (median 62 versus 39 months). Survival is better after good cytogenetic response or complete remission. Combined chemo-IFN therapy is currently under study in an attempt to improve cytogenetic response. In terms of the molecular biology however, residual disease is almost always present and relapse is frequent.(ABSTRACT TRUNCATED AT 250 WORDS)