Bone marrow immunohistochemical studies of angiogenic cytokines and their receptors in myelofibrosis with myeloid metaplasia

Bone marrow specimens from I I patients with myelofibrosis with myeloid metaplasia (MMM) and seven normal controls were studied immumohistochemically to determine expression of transforming growth factor beta(TGF-beta), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and corresponding receptors. Staining distribution and intensity for TGF-beta, PDGF, VEGF, TGF-beta type II receptor, a receptor for PDGF, and receptors for VEGF and bFGF were similar in patients and controls. Bone marrow from 10 MMM patients showed increased TGF-beta type I receptor (TGF-betaRI) expression in small vessel endothelial cells. Eight patient specimens had bFGF overexpression in megakaryocytes. Increased microvessel density and decreased concentration of bFGF-staining stromal cells accompanied these changes. Microvascular TGF-betaRI upregulation and bFGF overexpression by megakaryocytes may cause bone marrow microenvironmental changes in MMM patients. (C) 2003 Elsevier Science Ltd. All rights reserved.