IMMUNOHISTOCHEMICAL LOCALIZATION OF FACTOR-XIIIA IN CHRONIC VENOUS INSUFFICIENCY

Objective: Factor XIIIa (FXIIIa) of the coagulation cascade (fibrin st abilizing factor) plays a crucial role in wound healing. Its plasma ac tivity is significantly decreased in patients suffering from diseases accompanied with pathologically increased uptake of fibrin. Design: Im munohistochemical localization of FXIIIa and immunofluorescent histolo gical labelling of fibrin in patients' biopsies and in control specime ns. 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 al l biopsies. Additionally, 10 biopsies from ulcer edges were stained wi th FXIIIa. Results: The fibrin uptake in ulcer tissue exceeded the amo unt found in control biopsies. Specimens taken from the ulcer edges co ntained the greatest amount of FXIIIa in both pericapillary and inters titial regions, followed by the controls. Granulation tissue taken fro m venous ulcers showed less FXIIIa around capillaries and in the inter stitium than specimens of both other groups. Conclusion: Local FXIIIa deficiency in ulcer tissue may contribute to impaired wound healing. S clerosis found in ulcer edges may be the morphological correlate of th e high enzymatic concentrations found in specimens from this area.