Tryptase-positive mast cells and angiogenesis in keloids: a new possible post-surgical target for prevention.

Literature data indicate that mast cells (MCs) are involved in angiogenesis through the release of several pro-angiogenetic factors among which tryptase, a serine protease stored in MC granules, is one of the most active. However, no data are available concerning the role of MCs during keloids' angiogenesis. In this study, we evaluated the correlations of the number of MCs positive to tryptase (MCDPT) and microvascular density (MVD) within a series of 15 keloids and 10 normotrophic scars, by means of immunohistochemistry and image analysis methods. Data demonstrated a significant difference of MVD and MCDPT between keloids and normotrophic scars and a significant correlation between MVD and MCDPT in keloids. Our results suggest that tryptase-positive MCs might play a key role in keloids' angiogenesis. In this context, several tryptase inhibitors might be clinically evaluated as a possible new anti-angiogenetic approach to prevent keloid formation after surgery.