Angiogenesis in Waldenström's macroglobulinemia

Angiogenesis represents an essential step of disease progression in several hematological malignancies. In Waldenström's macroglobulinemia (WM) the bone marrow microvessel density is increased in 30%-40% of patients but seems to have no impact on survival. Angiogenic cytokines, such as angiogenin, vascular endothelial growth factor, and basic fibroblast growth factor are increased in the serum of WM or IgM-MGUS patients, while the ratio of angiopoietin-1/angiopoietin-2 is reduced in WM but not in IgM-monoclonal gammopathy of undetermined significance (MGUS). Angiogenin and angiopoietin-1/angiopoietin-2 ratio correlates with disease activity and clinical features of WM. Macrophage and mast-cell chemoattractants, such as macrophage inflammatory protein-1 alpha are also elevated in the serum of patients with WM, while both macrophages and mast cells that are increased in the WM microenvironment have angiogenic properties and participate in the angiogenesis process in several malignancies. This review summarizes all data available by November 2008 (end of literature search) for the role of angiogenesis in the biology of WM and its correlation with clinical and laboratory features of the disease.