TREATMENT OF WALDENSTROMS MACROGLOBULINEMIA WITH VERY-LOW DOSES OF ALPHA-INTERFERON

Waldenstrom's macroglobulinemia (WM) is a differentiated B-cell malign ancy which is usually less responsive to standard chemotherapy because of low-proliferating cells. Interferon alpha has been shown to posses s a therapeutic action in numerous B-cell malignancies including the e arly stage of chronic lymphocytic leukemia, multiple myeloma, follicul ar lymphoma and hairy cell leukemia. Fourteen patients with progressiv e WM were included in a pilot study using very low dose of interferon alpha-2a (1 Million Units 3 times a week). The mean duration of treatm ent was 10.3 months (range 2-44). Six of 14 (42%) patients presented a n increase in the hemoglobin level (greater than or equal to 0.9g/dL) and 4/14 (28%) had a substantial decrease of the monoclonal component (greater than or equal to 20% of reduction). Only two patients present ed both types of response, while the others with an increase in the he moglobin level had a slight decrease in the monoclonal component (MC) (1 patient), a stable MC (1 patient) or a slight increase of MC (1 pat ient). One additional patient had a 15% decrease of the MC with a stab le hemoglobin level. Response was observed within 3 months with a medi an duration of 6 months. Treatment was stopped for 3 patients because of flu-like symptoms (2 patients), or thrombocytopenia (1 patient). Fo llow up was possible in 12 patients lasting up to a maximum of 30 mont hs after discontinuing treatment, Seven patients died, including 4 wit h progressive disease, two of infection and one of cardiac failure. In the view of these results, very low dose of interferon alpha may cons titute a new approach for treatment of some cases of WM.