Human Leukocyte Interferon to Control Thrombocytosis in Chronic Myelogenous Leukemia

Abstract

Nine patients with refractory chronic myelogenous leukemia and severe symptomatic thrombocytosis (≥ 1 x 10⁶ platelets/mm³) were given partially purified human leukocyte interferon-alpha. A significant decline in platelet counts, from a mean (> SE) of 1.71 ± 0.53 x 10⁶/mm³ to a mean of 0.52 ± 0.24 x 10⁶/mm³ (p < 0.01), resulted in all patients. Maintenance of low platelet counts was achieved in two patients for more than 143 and 300 days, respectively. Treatment with human leukocyte interferon-alpha was stopped in the remaining patients because of increases in the leukocyte count, toxicity, or both. Our preliminary observations suggest that human leukocyte interferon-alpha may significantly alleviate progressive thrombocytosis in advanced chronic myelogenous leukemia. Further studies of human leukocyte interferon-alpha and chemotherapeutic agents are indicated.