Immunolocalization of bFGF in Pterygia: Association with mast cells

Purpose. To examine the expression of basic fibroblast growth factor in pterygia and determine whether mast cells contain basic fibroblast growth factor (bFGF) in this disease process. Methods. Formalin-fixed paraffin- embedded tissue samples of pterygia (n = 14) were used to study the expression of bFGF with immunohistochemistry. Seven samples were also double labeled with specific antibodies to bFGF and tryptase (a specific mast cell marker). Results. In all tissue samples examined, bFGF was specifically localized in blood vessels, epithelium, and a subset of connective tissue cells. The majority of bFGF-positive connective tissue cells were also tryptase positive (90.4±3.6%). Nearly all the tryptase-positive cells (mast cells) in the pterygia tissues coexpressed bFGF (98±1.5%). Conclusions. These findings suggest that bFGF may have biologic effects on the epithelium and blood vessels in pterygia, with epithelial and endothelial cells as a possible source. In addition, mast cells contain bFGF in the pterygia tissues examined in this study. The mast cells may serve as an additional source of bFGF, possibly modulating a variety of cell types as well as the extracellular matrix in pterygia.