A study of bone marrow angiogenesis and its correlation with serum vascular endothelial growth factor levels in acute leukaemia

Background: Angiogenesis, which is the development of new capillaries from existing blood vessels, occurs in both the developing embryo and postnatal life. The growth of solid tumours requires the development of micro vessels; therefore, tumour expansion correlates with the extent of angiogenesis.Methods: A prospective study was conducted on bone marrow trephine biopsies of 40 new cases of acute leukaemia diagnosed on complete blood count, bone marrow aspiration examination, and flow cytometry, including 20 control cases. Micro sections were stained with immuno-histochemical stains using monoclonal antibodies to CD31, CD34 and vWF. Micro vessel density was analysed at a 400× using automated image analyser by two investigators independently. Data were calculated, tabulated and statistically analysed using statistical package for the social sciences (SPSS) statistical program version 18.Results: A total of 1522 micro vessels were analysed using CD31 including 802 in acute myeloid leukaemia (AML), 512 in acute lymphocytic leukemia (ALL) and 208 in the control group. The bone marrow microvessel density (MVD) in acute myeloid leukaemia using CD31, CD34 and Von Willebrand factor (VWF) was 70.83±20.76, 66.48±18.99 and 60.32±18.75 respectively while MVD in acute lymphoblastic leukaemia was 62.74±21.09, 70.58±22.46 and 51.22±21.13 respectively. The study revealed significant difference between AML, ALL and normal bone marrow cases by using CD31, CD34 and vWF antibody. Serum vascular endothelial growth factor (VEGF) concentration in AML, ALL and control group was 163.74±119.03, 168.23±154.22 and 43.45±9.14 respectively.Conclusions: Higher micro vessel density was observed in acute leukaemia. Present findings suggested the potential significance of characteristics of micro vessel density as potential prognostic marker as well as its application in improved selection of patients for anti-angiogenic and other treatments.