ELEVATED LEVELS OF PDGF-ALPHA RECEPTORS IN KELOID FIBROBLASTS CONTRIBUTE TO AN ENHANCED RESPONSE TO PDGF

Despite a number of studies, the etiology of keloids remains unknown. We have investigated the response of fibroblasts derived from keloid t issue and normal adult skin to platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and fibroblast growth factor (FGF). Kel oid fibroblasts were more responsive in both chemotactic and mitogenic assays to all three isoforms of PDGF than fibroblasts from normal ski n. No enhanced response of the cells to either EGF or FGF was detected . The enhanced PDGF response of keloid fibroblasts appears to be media ted by elevated levels of PDGF alpha receptors, which are 4-5 times hi gher than those in normal human skin fibroblasts.