Bone marrow angiogenesis and circulating plasma cells in multiple myeloma

Bone marrow (BM) angiogenesis is increased in multiple myeloma (MM) and has prognostic significance. The presence of circulating plasma cells (PCs) in MM is associated with a poorer prognosis. We examined BM biopsies obtained at diagnosis of MM for angiogenesis, and correlated the microvessel density (MVD) with the presence of circulating PCs. There was a positive correlation between the absolute number of circulating PCs and the mean MVD. This relationship was independent of the disease activity and of the PC burden in the marrow. The increased angiogenesis may promote plasma cell proliferation and enable PC migration into the circulation.