Does CD34 Staining Reflect the Angiogenic Process in the Bone Marrow? An Analysis of a Series of Chronic Myeloid Leukemia Patients

Backgorund: Angiogenesis is associated with growth, dissemination and metastasis of tumours. Measurement of Microvascular Density (MVD) is a quantitative method of assessment of angiogenesis and would give a proportional co relate of the angiogenic process in tumours. The aim of this study is to measure the MVD by using CD34 staining in various phases of Chronic Myeloid Leukemia (CML) and type of CML (Granulocytic/Granulocytic Megakaryocytic) (G/GM) and to co-relate micro vascular densities with the grade of fibrosis. Materials and Methods: Bone marrow biopsy specimens of 30 CML patients and 20 non-CML (controls) cases that required bone marrow biopsy were subjected to CD34 staining and H&E staining. The mean MVD in CD34 slides was assessed by selecting hot spots and MVD was measured in these fields in high power (40 x magnification) and the mean MVD was calculated by taking the average of four hot spots per field. Grade of fibrosis and phase of CML, type (G/GM) were assessed in H&E slides. The controls were matched with respect to age and gender. Results: Among 30 patients with CML, 21 were in chronic phase, five in accelerated and four in blast crisis. A normal distribution was obtained for MVD of both CML cases and controls using tests for normality. Comparison of mean MVD between CML and controls by student t-test showed a significant increase in MVD of CML cases (p = 0.00026). However, no significant difference in MVD between the three phases viz, Chronic, accelerated and blast crisis phase (p = 0.302) was obtained by using one way ANOVA. Comparison of Grade of fibrosis with MVD using independent t-test showed no significant difference in MVD between low (Grade1&2) and high grade (Grade 3&4) (p = 0.805). No significant difference in MVD was obtained between G and GM types of CML using independent t-test (p =0.381). Conclusion: The study shows that there is a significant increase in MVD in CML cases than controls but no significant difference in MVD could be demonstrated between different phases of CML, histological types of CML and grades of fibrosis in CML.