[The dose of alpha interferon in induction and maintainance therapy of hairy cell leukemia]

The efficacy of different doses of interferon (IFN) alpha in the induction therapy of hairy cell leukemia was studied. Recombinant IFN alpha-2b was administered subcutaneously every second day at an initial dose of 4 x 10(6) U/m2 (7 patients), 2 x 10(6) U/m2 (14 patients) and 1 x 10(6) U/m2 (13 patients). Each dose was effective to induce a normalization of blood cell counts and a reduction of bone marrow infiltration in the majority of patients treated. A delayed increase in granulocyte counts, however, was noted in patients treated with 1 x 10(6) U/m2, and 2 of them only achieved a partial hematological remission after 1 year of treatment. After the induction of stable remission, patients were randomized into 2 different schedules of maintenance therapy. Five of 7 patients receiving IFN alpha-2b at a total dose of 1 x 10(6) U twice a week, and 6/8 patients treated with 2 x 10(6) U once weekly, respectively, received this therapy for 1 year and remained in stable remission.