Background: Aim of this placebo-controlled clinical study was to examine the expression pattern of coagulation factor XIIIa in patients with chronic venous leg ulcers and the impact of a 10 day topical factor XIII treatment on ulcer healing, leg ulcer size and radius reduction.
Patients and methods: 24 patients were stratified into two groups, each consisting of 12 patients, with leg ulcers > 1.000 mm2, or < 1.000 mm2. Four patients of each study group were assigned to the control group (n = 8). All leg ulcers were treated by topical application of non-adhering dressings and compression therapy. Patients of the treatment group (n = 16) were treated by additional topical treatment off factor XIII twice daily for ten days. Immunohistochemical staining of leg ulcer specimens before and after treatment (day 10) was performed in all patients.
Results: The immunohistochemical staining of factor XIIIa in all specimens before and after therapy showed no significant increase in the expression of factor XIIIa. Comparison of the leg ulcer size, radius and daily radius reduction in the treatment and control group showed no significant differences in values of patients with leg ulcers > 1.000 mm2. However, a decreased leg ulcer size and radius was found in patients of the treatment group with more acute leg ulcers < 1.000 mm2 in contrast to patients with larger leg ulcers (daily ulcer radius reduction from day 0-10; 0.31 mm versus 0.13 mm, p < 0.015).
Conclusions: These results indicate that locally applied factor XIII promotes especially wound healing of more acute smaller venous leg ulcers. Since immunohistochemical staining of factor XIIIa showed no significant differences before and after therapy, we propose that factor XIII is inactivated rapidly after local application on venous leg ulcers.