JAK 2 V617 mutation with myeloid Hyperplasia and blast formation in idiopathic myelofibrosis

Objectives: the myeloproliferative disorders refer to clonal disorders of haemopoiesis that lead to an increase in the number of one or more mature blood cell progeny. idiopathic myelofibrosis is a clonal myeloproliferative disorder of the pluripotent haemopoeitic stem cell in which a clonal proliferation of multiple cell lineages is accompanied by progressive bone marrow fibrosis. jak-2 mutation has been identified as the first genetic marker that is directly associated with the pathogenesis of myeloproliferative disorder (polycythaemia vera,essential thrombocythaemia and idiopathic myelofibrosis). the purpose of this study is to document the total leukocytes count and circulating blast of idiopathic myelofibrosis in jak2 positive and jak2 negative patients. design: comparative and cross sectional study. place and duration of study: the study was carried out from january 2004 to december 2008,at the department of haematology,armed forces institute of pathology,rawalpindi. method: a total number of 35 patients were studied in which 19 patients were jak2 positive and 16 patients were jak2 negative. sample collection technique was purposive non-probability sampling. variations were observed among the studied jak2 positive and jak2 negative patients regarding total leukocytes count and the presence of circulating blast cells. results: the total leukocytes count and the presence of blast cells were compared in between jak2 positive and jak2 negative patients. patient's positive for jak2 mutation had higher total leucocytes counts (a mean of 20.4 × 10 9/l) and less circulating blasts 7/35 (36.8%) as compared to patients negative for jak2 (a mean 12.4 × 10 9/l) and circulating blasts 12/35 (75.0%). conclusion: the jak2 mutation is associated with expansion of the myeloid lineage and less tendency to blasts transformation.