Immunohistochemical Localization of Factor XIIIa in Chronic Venous Insufficiency

Abstract

Objective: Factor XIIIa (FXIIIa) of the coagulation cascade (fibrin stabilizing factor) plays a crucial role in wound healing. Its plasma activity is significantly decreased in patients suffering from diseases accompanied with pathologically increased uptake of fibrin. Design: Immunohistochemical localization of FXIIIa and immunofluorescent histological labelling of fibrin in patients' biopsies and in control specimens. Procedure: Twenty-five biopsies were taken from granulation tissue of venous ulcers. Specimens of unimpaired wound healing ( n = 10) served as controls. Concentrations of FXIIIa and fibrin were estimated in all biopsies. Additionally, 10 biopsies from ulcer edges were stained with FXIIIa. Results: The fibrin uptake in ulcer tissue exceeded the amount found in control biopsies. Specimens taken from the ulcer edges contained the greatest amount of FXIIIa in both pericapillary and interstitial regions, followed by the controls. Granulation tissue taken from venous ulcers showed less FXIIIa around capillaries and in the interstitium than specimens of both other groups. Conclusion: Local FXIIIa deficiency in ulcer tissue may contribute to impaired wound healing. Sclerosis found in ulcer edges may be the morphological correlate of the high enzymatic concentrations found in specimens from this area.