EXPERIENCE WITH THE USE OF AZACITIDINE IN PATIENTS WITH LOW RISK MYELODYSPLASTIC SYNDROME

The chronic myeloproliferative syndromes or myeloproliferative neoplasms (MPN), are clonal hematopoietic stem cell diseases, in which there is increased proliferation of myeloid series with ineffective maturation, which leads to peripheral blood leukocytosis, increased erythrocyte mass or thrombocytosis. Several progress to fibrosis or leukemic transformation. A mutation in the pseudokinase domain JH2 gene Janus kinase 2 (JAK2 V617F) was described in myeloproliferative diseases. This mutation is associated to increased risk of tromboembolic events in some of these MPN. We present three cases of patients with MPS/MDS with JAK-2 positive. The first one is a 80 – years- old with “refractory anemia with ring sideroblasts and thrombocytosis” RARS-T and JAK-2 positive with prior systemic arterial hypertension and prostate adenocarcinoma history and radiotherapy treatment in 2007. Myelogram revealed dyseritropoesis and dysmegakaryopoesis above 10% ; assynchronism of maturation and binucleation; presence of micromegakariocytes, megakaryocytes hipolobulated; 1% of plasmocytes and 81% ringed sideroblasts. A bone marrow biopsy revealed a hypercellular marrow with architectural disorder, characterized by megaloblastóides erythroblasts and megakaryocytes arranged in peripheral position. Slight increase in network and reticulin myelofibrosis grade I. Cytogenetic karyotype revealed 46,XY. Hematologic parameters presented are: Hb 78,7g/L; leukocytes 7.740/mm3 and platelets 949/mm3. The second case is a 69 years old male patient, with MPS/MDS. The bone marrow revealed a predominance of megakaryocyte and granulocyte without evidence of myelofibrosis. Peripheral blood count revealed anemia (Hb: 109 g/L) and leukocytosis ( Lc: 16.500/mm3). The second case is a 69 years, with pancitopenia (Hb= 103 g/L; Leucocytes= 2700/mm3 and platelets= 127000/mm3). Myelogram revealed a very hipocelular bone marrow with alterations in erythrocytes form, micromegakaryocytes and iron deposit absence. Biopsy showed hiperlasia of megakariocytic lineage and moderate increase of reticuclin. The cytogenetic was not made because the sample was hipocellular, seggering fibrosis. The last patient is a 66 years old male with MDP/MDS andV617F JAK 2 positive. He presented anemia and leucocytosis (Hb= 109 g/L and leucocytes= 16500/m3). In mielogram is observed mild dyseritropoiesis and iron deposit absence. Bone marrow biopsy revealed hipercelurity of 80%, with predominance of megakaryocytes and granulocytes. There was no evidence of mielofibrosis. In these diseases we consider the possibility of patients being benefited by medication anti JAK2 resulting in improved quality of life.

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