الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Acute Leukemia is a malignant disorder that involves the bone marrow and blood systems resulting in the uncontrolled growth of abnormal white blood cells. Acute leukemia is classified into two types acute lymphoblastic and acute myeloid leukaemia. Several risk factors have been associated with the development of acute Leukemia include age, genetic disorders, antecedent hematologic disease, exposures to viruses as well as radiation, chemical, or other occupational hazards and previous chemotherapy. FAB classification and the WHO classification use all available information including morphology, cytochemistry, immunophenotype, genetics, and clinical features to define clinically significant disease entities. Assessment of prognosis involves a number of clinical and laboratory criteria such as age, gender, race, WBC count (at diagnosis), immunophenotyping, cytogenetic and molecular findings, cytogenetics response to therapy, and MRD and other recent criteria such as transcription factors, cytokines and apoptosis. The current challenge is the identification of patients at high risk at time of diagnosis, who may undergo more aggressive therapy to improve their outcome.In ALL there is unfavourable prognostic factors such as age less than 2 years or more than 10 years, males, high TLC, increased hemoglobin level, low platelet count. Immunophenotyping is likely to remain of major importance in selecting therapies. In AML there is unfavourable prognostic factors such as increasing age, increased Hb, low platelets count, secondary AML following various hematological disorders such as MDS, presence of extramedullary leukaemia, presence of CNS disease, megaloblastic features and the absolute percentage of erythroblasts and FAB types M0, M6 and M7. While M2, M3 and M4Eo have better prognosis. High expression of CD11b and low levels of Tdt expression associated with good prognosis. On the other hand, the expression of CD34, CD56 and CD7 has been associated with poor prognosis. in AML DNA cytosine methylation is a key mechanism of epigenetic regulation of gene expression AML entities. The chemokine receptor CXCR4 is an independent adverse prognostic.