الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Acute leukemias are a heterogeneous group of neoplasms arising from transformation of hematopoietic stem cells , usually with a retained partial capacity of differentiation. In leukemia, immature blasts are not retained within the marrow, suggesting a breakdown of adhesive mechanisms. In fact, altered expression of adhesion molecules has been proved to affect leukemic cell polarization and subsequent cell migration.
In normal bone marrow, E-cadherin is expressed on erythroid progenitors, CD34+ stem cells, and stromal cells, where it likely contributes to intercellular interactions during hematopoiesis. Also Integrins such as α5β1 integrin represent an essential component of the bone marrow microenvironment that regulates cell survival by interacting with the extracellular matrix.
So, the aim of the current work was to evaluate the serum level of soluble E- cadherin and cell surface expression of α5β1integrin in patients with acute leukemia, in order to extrapolate their possible values in those patients.
The present study was conducted on twenty patients with acute leukemia and ten age and sex-matched healthy normal individuals as a control group. Leukemic patients included 11 patients with AML and 9 patients with ALL. Serum level of soluble E-cadherin was estimated using commercial enzyme linked immunosorbent assay. α5β1integrin cell surface expression on the surface of PBMCs was assessed by indirect immunoflourescence assay.
Regarding the common symptoms and signs of acute leukemia, splenomegaly, hepatomegaly and lymphadenopathy were more prominent in ALL than in AML patients (≈ 78%, 56% and 77% vs ≈ 55%, 36% and 18%, respectively). Similarly, fever and weight loss were more evident in ALL than in AML patients (≈ 56% vs 36%, respectively). In addition, about 46% of AML and 22% of ALL patients presented with bleeding and purpura. Fatigue was also a common presenting feature of both groups, ≈ 44% and 55% of ALL and AML patients, respectively.
Immunological results revealed that the mean serum level of soluble E-cadherin in leukemic patients (89.70 ± 43.22 ng/ml ) was significantly (p = 0.0108) lower when compared to corresponding level in the control group (128.77 ± 37.58 ng/ml). However, no significant difference was observed between AML and ALL patients. When AML and ALL patients were compared separately with the control group, the decrease in soluble E-cadherin level was highly significant in AML group (74.70 ± 47.66 ng/ml, p= 0.0049) while it did not reach the significant level in ALL group of patients (108.03 ± 30.16 ng/ml, p=0.102).
On the contrary, current results showed that the mean cell surface expression of leucocytic α5β1 integrin in patients with acute leukemia was significantly higher (5% grade I, 15% grade II and 80% grade III, p=0.0001) compared to that in the control group (60% grade I,40% grade II). However, there was no significant difference between the mean cell surface expression of α5β1 integrin in AML (18 % grade II and 82% grade III) and that in ALL (11.1% grade I, 11.1% grade II and 77.8% grade III) groups. When AML and ALL patients were compared separately with the control group, α5β1 integrin expression was significantly higher in both leukemic groups (p= 0.0001, 0.0038, respectively).
Negative significant correlation was observed between serum E-cadherin concentration and bone marrow blast percentage after the induction chemotherapy. No other significant correlation was observed between serum E-cadherin concentration or α5β1 integrin cell surface expression and both clinical or hematological data. Moreover, No significant correlation was observed between serum E-cadherin concentration and α5β1 integrin cell surface expression.
In conclusion, current results showed decreased serum level of soluble E-cadherin and increased expression of α5β1 integrin on peripheral blood mononuclear cells in patients with acute leukemia. A negative significant correlation was observed between basal serum E-cadherin level and BM blast cells percentage after the induction chemotherapy. These observations serve the notions of metastasis and invasion in acute leukemia.