Characterization of human prostate mast cells and their increase in periprostatic vein thrombosis

Recent data suggest that mast cells (MCs) and their products are involved i n the pathophysiology, of thrombosis. In the present study, we analyzed the number distribution, and phenotype of prostate MCs and periprostatic MCs i n patients with unilateral periprostatic vein thrombosis (PVT) by immunohis tochemical analysis and electron microscopy. MCs reacted with monoclonal an tibodies to tryptase, chymase, and c-kit/CD117 and stained positively for t issue-type plasminogen activator (tPA) and urokinase receptor (uPAR/CD87) b ut did not express detectable urokinase (uPA) or plasminogen activator inhi bitors (PAI-1, PAI-2). We found an increase in the mean c SEM number of MCs in PVT compared with control (PVT 14.36 +/- 1.57 vs control, 5.23 +/- 0.57 /mm(2)). The majority of MCs accumulated in the adventitia of thrombosed ve ins and showed a decrease in chymase expression. As MCs increase in number in PVT and express a profibrinolytic phenotype, we hypothesize that MC-deri ved molecules have a role in endogenous fibrinolysis.