Abstract
Two patients with essential thrombocythemia were successfully treated by administering native α-interferon (α-IFN). One patient was a 38-year-old man in whom thrombocytosis was found accidentally. His platelet count on admission was 880,000/μl and megakaryocytes increased. Three million units of α-IFN was administered subcutaneously everyday, and the platelet count decreased gradually to about 500,000/μl within 2 weeks. The other patient was a 66-year-old woman who visited our hospital complaining of tenderness and swelling of the fingertips. Her platelet count was 1,610,000/μl, and megakaryocytes increased and showed abnormal morphology. Six million units of α-IFN was administered subcutaneously every other day. The tenderness and swelling of the fingertips disappeared soon after the beginning of α-IFN administration. The platelet count decreased to about 500,000/μl within 10 days, but she developed itching of the skin over the entire body. Therefore, α-IFN treatment was discontinued. It was suggested that α-IFN suppresses not only the maturation and proliferation of the progenitors of megakaryocytes but also the production of platelets from megakaryocytes. Administration of α-IFN should be considered in treating patients with essential thrombocythemia, because effects appear soon and α-IFN does not induce a second malignancy.
