الفهرس 
Introduction and aim of the work
Acute myeloid leukemiaOnly 14 pages are availabe for public view
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Abstract
AML is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal WBCs that accumulate in the BM and interfere with the production of normal blood cells. AML is the most common acute leukemia affecting adults, and its incidence increases with age.
Identification of a leukemic cell population, as for any malignancy, depends upon the recognition of non-random patterns of antigen expression as different from that of the tightly regulated normal situation. Election of aberrant phenotypes is of clinical importance not only for accurate diagnosis of AML, but also for AML sub classification and detection of prognosis. The incidence of the aberrant phenotypes in AML is still controversial and divergent results have been found by different groups.
The CD7 is a T-cell antigen that is expressed throughout T-lymphocyte differentiation. It is present on 85% to 90% of peripheral blood T-lymphocytes. The expression of CD7 in AML was explained by several mechanisms including lineage infidelity and lineage promiscuity. The CD7 is the most commonly detected aberrant lymphoid marker on AML, being found on 12–37% of cases.
The current study was done in clinical pathology department, Assiut University Hospital. The study included 32 newly diagnosed AML patients, recruited from clinical hematology department, after BMA and immunophenotyping in the period from 2015 to 2016.
The ages of the patients ranged from from 17 to 80 years with mean (± SD) 46.25 ± 18.19.
All patients were subjected to the following:
I-Medical history including (fever, bleeding and therapeutic history).
II-Clinical examination: general examination and system review.
III-Laboratory investigations:
A-Complete blood counting (CBC) using automated blood cell counter, CELLDYN (1700).
B-Examination of peripheral blood film stained with Lishman stain for differential leukocytic count and manual reticulocyte count.
C-Erythrocyte sedimentation rate (ESR)
D-Serum LDH level, calcium level, liver functions test and kidney functions test.
E-Examination of Leishman stained BMA smears for assessment of BM cellularity and morphological BM infiltration.
F-Flow cytometric immunophenotyping analysis of BMA sample was performed using (HLA-DR, CD45, Cytoplasmic MPO, CD13, CD33, CD34, CD117, CD7, CD10, CD4, CD8 and CD19 as primary panel) and (CD41, CD61, CD36, Glycophorin A as secondary myeloid panel) using BD FACSCalibur 4 color flow cytometer.
G-Reverse transcriptase polymerase chain reaction (RT-PCR): CD7 expression positive AML cases were subjected to RT-PCR to determine CD7 gene expression.
The current study revealed the following findings:
The study using MoAb flow cytometric measurements had found the frequency of CD7 expression in newly diagnosed AML cases to be 18.1 % by flow cytometry. AML cases with positive CD7 expression by flowcytometry were subjected to RT-PCR to determine gene expression. All cases with positive CD7 by flowcytometry were negative for mRNA expression by RT-PCR. The different possibilities that could lead to this discrepancy were discussed.
Conclusion
This study was carried on 32 newly diagnosed AML cases. The patients were admitted to the Hematology Unit, Internal Medicine department, Assiut University Hospitals, from September 2015 until December 2016. The study was done in the clinical pathology department of Assiut University. This study used both flow cytometry and RT-PCR for the detection of CD7 expression. The study revealed that the frequency of CD7 expression in newly diagnosed AML cases to be 18.1 % by flow cytometry. The AML cases with positive CD7 expression by flowcytometry were subjected to RT-PCR to determine gene expression. All cases with positive CD7 by flow cytometry, were found negative for CD7 gene expression by PCR.
Recommendations
• All ectopic expression of surface marker CD7 by flow cytometry, should be confirmed by an independent method that does not rely on the use of monoclonal antibodies such as RT-PCR.
• Further molecular studies are required to clarify the expression regulation of CD7 gene, specially in cases of acute myeloid leukemia.