Cellular vascular endothelial growth factor and serum angiogenin in acute myeloid leukemia: clinical and prognostic significance

Background:Increased angiogenesis and angiogenic factors play an important role in hematologic malignancies. Acute myeloid leukemia (AML) is associated with a considerable increase in bone marrow vascularity. Vascular endothelial growth factor (VEGF) and angiogenin (ANG) are two prominent angiogenic mediators. Therefore, we aimed to examine the cellular expression of VEGF and serum ANG level in adult AML patients and to assess their prognostic impact on disease outcome.Materials and methods: The study was carried out on 60 newly diagnosed adult AML patients compared with 25 age-matched and sex-matched controls. Patients were diagnosed and classified according to the French–American–British/WHO criteria by immunophenotyping and cytogenetic analysis. The cellular expression of VEGF in blast cells was assessed by flow cytometry. Serum levels of ANG were measured using a sandwich enzyme-linked immunosorbent assay.Results: AML blasts significantly overexpressed VEGF (median percentage expression, 30%; median mean fluorescence intensity, 3.8) compared with normal individuals ( 5%; 0.57; P 0.01). Similarly, the serum levels of ANG were significantly higher in AML patients (mean±SD, 212.5±77.1 ng/ml) compared with the controls (mean±SD, 66±2.5 ng/ml; P 0.01). High levels of VEGF, above the median ( 30%), together with serum ANG levels of AML patients showed no relationship with the studied clinical and laboratory parameters, French–American–British subtypes, or cytogenetic risk groups (P 0.05); however, they were significantly associated with a poor response to treatment and a higher mortality rate (P 0.01).Conclusion: Cellular VEGF expression and serum ANG levels are significantly increased in AML patients and have been identified as independent poor prognostic indicators linked to accelerated angiogenesis and consequently a more aggressive disease outcome.