Increased levels of tissue factor pathway inhibitor may reflect disease activity and play a role in thrombotic tendency in Behçet's disease.

Tissue factor pathway inhibitor (TFPI) is a Kunitz-type proteinase inhibitor that has a crucial role in haemostasis and is primarily synthesized in the vascular endothelium. We investigated plasma total TFPI, antiphospholipid antibodies, and some other coagulation and fibrinolytic system parameters in 30 patients with Behçet's disease and 15 controls by the enzyme-linked immunosorbent assay method. TFPI levels were significantly higher in the Behçet's group (119 +/- 57.5 ng/ml) compared with the control group (74.8 +/- 31.5) (P < 0.009). We also noted a statistical significance in TFPI levels between patients with active disease (n:16) (139 +/- 55) and patients without activation (n:14) (96 +/- 53) (P < 0.03), whereas inactive patients lacked any significance when compared with the control group (P < 0.29). Other parameters disclosed no statistical significance between patients and control group except for elevated fibrinogen and plasminogen activator inhibitor-1 levels in the patient group (P < 0.003). Increased levels of TFPI may reflect a defensive mechanism like in other diseases characterized by thrombotic tendency and represent a parameter of disease activity.