The Change of Vascular Endothelial Growth Factor and Microvessel Density Following Imatinib Mesylate Therapy and Allogeneic Bone Marrow Transplantation in Chronic Myeolid Leukemia.

Chronic myeloid leukemia(CML) is a clonal myeloproliferative disorder and increased angiogenesis in bone marrow is a feature of CML. Vascular endothelial growth factor(VEGF) is a potent angiogenic peptide and microvessel density(MVD) is increased in bone marrow of CML. In this study, the effect of imatinib mesylate therapy on angiogeneisis was investigated and compared with allogeneic bone marrow transplantation(BMT) with philadelphia chromosome positive/BCR-ABL+ CML in first chronic phase. Immunohistochemical staining for detecting VEGF protein was performed by labeled avidin-biotin method on the formalin-fixed and paraffin embedded bone marrow biopsy samples of 10patients of allogeneic BMT, 20patients of imatinib mesylate therapy and 10normal control. Initial and sequential, after at least 12 months of therapy, bone marrow biopsy examed and all patients achieved complete cytogenetic remission. Microvessel was scored in at least 3 areas(*200 fields) of the highest MVD in representative sections of each bone marrow biopsy specimen using immunohistochemistry for CD32 antigen. Patients with Imatinib mesylate therapy and allogeneic BMT induced a significant reduction of MVD (normalization in comparison with controls). MVD was no significant difference between the patients with imatinib therapy and allogeneic BMT. VEGF was mainly expressed myeloid progenitors and less abundantly megakaryocytes and mature granulomonocytic cells. Expression of VEGF, it was significantly decreased in patients with Imatinib mesylate therapy and allogeneic BMT(normalization in comparison with controls). VEGF expression was no significant difference between the patients with imatinib therapy and allogeneic BMT. First line therapy with imatinib mesylate was normalization of bone marrow vascularity compared with allogeneic bone marrow transplantation of CML in first chronic phase.