الفهرس 
ACUTE LEUKEMIAOnly 14 pages are availabe for public view
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Abstract
The hemoglobin-haptoglobin scavenger receptor (CD163/HbSR) is a monocyte/macrophage-restricted transmembrane protein that is highly sensitive and specific in distinguishing AML with monocytic component from other AML classes.
The interest in this molecule has growen exponentially, since CD163 as an endocytic receptor selectively expressed in macrophages with preservation of regulation and function after malignant transformation can be used for leukemic blasts targeting by several substances, for instance DNA and drugs chemically linked to haptoglobin/hemoglobin complexes, So used as a potential, novel, therapeutic target for a subset of patients with AML.
The aim of this study was to assess the value of CD163 expression in AML and ALL blasts in acute leukemia patients, and to correlate its expression with various clinical, laboratory and standard prognostic factors.
The present work measured cell-surface expression of CD163/HbSR on leukemic blast cells of 45 newly diagnosed acute leukemia patients (28 AML cases and 17 ALL cases). All patients were subjected to complete history taking, thorough clinical examination and laboratory investigations including: complete hemogram, bone marrow aspiration with examination of leishman- stained peripheral blood and bone marrow smears, immunophenotyping, and detection of the level of CD163 by flow cytometry. 10 subjects served as control group to clarify that CD163/HbSR is expressed on peripheral blood monocytes.
The CD163 was positively expressed in all cases of the monocytic sub-group of AML patients, and was positive in only 2 cases of the non-monocytic sub-group of AML patients. On comparing monocytic sub-group versus non-monocytic sub-group regarding number of cases positively expressed CD163; it showed a high statistically significant increase in expression of the marker among monocytic sub-group while in ALL patients CD163 expression was not observed except for only one case out of the 17 ALL patients.
No significant statistical association existed between CD163 expression and demographic, clinical or laboratory variables except for monocytic and myeloid markers (CD14, CD13, CD33 and CD15) and Hb concentration with in AML cases, and lymphadenopathy as well as pallor in ALL cases.
On analyzing the association between CD163 expression and the studied standard prognostic factors of acute leukemia, no significant association existed between CD163 and any of them in either group except for FAB subtypes in AML group.
In conclusion, these results demonstrate that CD163/HbSR is expressed not only on mature monocytes and macrophages but also on leukemic cells. We found the antigen exclusively expressed on the majority of monocytic and a significant subset of myelomonocytic leukemias, suggesting that the restriction of CD163/HbSR expression to cells committed to the monocytic lineage is preserved beyond malignant transformation; this lineage-restricted pattern of antigen expression may thus be useful for the immunophenotypic subclassification of leukemias. Also, CD163 expression couldn’t be regarded as an independent prongostic predictor for AML.