[Essential thrombocythemia: a 35-year experience and review of the literature]. / Trombocitemia esencial: experiencia de 35 años y revisión de la literatura.

Essential thrombocythemia (ET) is a clonal myeloproliferative disorder characterized by an uncontrolled rise in peripheral blood platelet count. The aim of this report was to determine the clinical and laboratory data of this disease in a 35 years revision. Of the patients with the diagnosis of ET, we selected those who fulfilled five of the six diagnostic criteria proposed by the Poli Vera Study Group. We found 14 cases (10 female and 4 male) with a median age of 54.5 years (range 29-74). The most frequent initial clinical finding was hemorrhage and in four cases the diagnosis was preoperative. Median platelet count was 1,355 x 10(9)/L (range 600 to 3,750). One case had iron deficiency which was corrected before ET was diagnosed. None has evolved to acute leukemia. Initially, most of the cases were treated with busulphan and two received alpha-interferon which was promptly changed to busulphan because of secondary effects. Three patients have died due to hemorrhagic complications and one due to thrombosis. ET has a low frequency in our country and must be considered an exclusion diagnosis. Iron deficiency may mask the diagnosis specially in the cases with a platelet count not very high. Treatment can provide in general a long survival of good quality of life.

Drug-induced agranulocytosis treated with granulocyte-macrophage colony stimulating factor.

Drug induced agranulocytosis (DIA) is a potentially lethal disorder characterized by selective neutropenia. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been utilized for its treatment. We report four cases of DIA treated with GM-CSF at the dose of 5 micrograms/kg/day. The patients presented infectious diseases at diagnosis. Median days to obtain 1 x 10(9)/L neutrophils and a normal neutrophil count (NNC), were 7(5-9) and 7.5 (6-10) days, respectively. The infectious disease at diagnosis improved and all patients are alive at the moment of this report. No other adverse effects than thrombocytosis (two cases) and thrombocytopenia (one case) were observed. We consider that GM-CSF could be a safe and effective alternative in the treatment of DIA.