Expression of basic fibroblast growth factor, nerve growth factor, platelet-derived growth factor and transforming growth factor-β in human brain abscess

Abstract

We correlated the histopathological findings of six human brain abscesses with the expression of basic fibroblast growth factor (bFGF), nerve growth factor (NGF), platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGFβ). The clinical courses ranged from 1 month to 1 year and viridans streptoccus was the major pathogen. In early abscesses, we demonstrated strong bFGF and moderate NGF and PDGF immunoreactivities in neutrophils and monocytes/macrophages infiltrating the abscess wall and in the fibrin layer lining the abscess center. In the subacute cases, growth of capillaries and fibroblasts into the fibrin layer and deposition of collagen resulted in the formation of a mesodermal layer between the abscess center and the outer gliotic layer. The proliferative non-neural cells (endothelial cells, fibroblasts and glial cells) expressed mild to strong bFGF, NGF and PDGF immunoreactivities, while strong TGFβ staining was seen in the extracellular matrix. A loss of growth factor expression and increased fibrosis was seen in the chronic case. These findings suggest that bFGF, NGF, PDGF and TGFβ produced by the continued influx of leukocytes and by the proliferating non-neural cells may mediate various steps of defense mechanisms and wound healing such as angiogenesis, fibrogenesis and gliosis. © 1994 Springer-Verlag.