Degree of fibrosis and its association with angiogenesis in the myelofibrotic bone marrow

Abstract

Background: Primary and secondary myelofibrosis has become a global burden due to its increased mortality and morbidity. Angiogenesis is a significant driving force in the development of fibrogenesis in the bone marrow, which leads to myelofibrosis. The microvascular density (MVD) with immunomarker CD34 can be used to assess the degree of angiogenesis. The objective of this study was to examine the association between degree of myelofibrosis and angiogenesis in hematological malignancies. Methods: Forty-six trephine biopsy specimens of various hematological malignancies with myelofibrosis were studied at the Department of Pathology of Bangabandhu Sheikh Mujib Medical University. Extent of myelofibrosis in each case was assessed by examining the reticulin and Masson’s trichrome stained sections using a semiquantitative grading system of bone marrow fibrosis (MF) within a scale of MF-0 to MF-3. Angiogenesis was measured by counting MVD in the ‘hotspots’ after immunostaining with CD34 antibody. Results: The trephine biopsy cases were grouped into early fibrotic (MF-1) and advanced fibrotic (MF-2,3) consisting of 16 (34.8%) and 30 (65.2%) patients, respectively. Angiogenesis was estimated as mean MVD count which revealed 16.7 ± 5.4 and 32.0 ± 11.5 in these groups, respectively. Significant difference of mean MVD values (P<0.001) between the early and advanced fibrotic groups revealed the association of angiogenesis and degree of myelofibrosis. Conclusion: MVD may be used to measure angiogenesis in myelofibrotic marrow along with other clinical and laboratory indices as a marker of disease activity in hematological malignancies, thus aiding disease prognosis.