Changes in the concentration and distribution of tissue factor pathway inhibitor in Behçet's disease and systemic lupus erythematosus: effect on the prethrombotic state.

BACKGROUND: Tissue factor pathway inhibitor (TFPI) is an anticoagulant which modulates the tissue factor (TF) dependent pathway, acting on the factor VIIa/TF complex, factor Xa, and thrombin. Although most TFPI is found in association with plasma lipoproteins and platelets, the functional pool is bound to vascular endothelium and is released into the circulation on stimulation with heparin or low molecular weight heparin (LMWH). OBJECTIVE: To assess the vascular endothelial TFPI pool in patients with Behçet's disease (BD) or systemic lupus erythematosus (SLE). METHODS: Plasma TFPI concentrations were determined before, and 20 and 60 minutes after subcutaneous LMWH injection in 15 newly diagnosed patients with BD and 12 with SLE, and in 12 healthy controls. RESULTS: Baseline median TFPI was 149.5 ng/ml in healthy subjects, and the percentage change in TFPI at 20 minutes (((value at 20th min - baseline value)/baseline value) x 100) was 575.2. TFPI concentrations in patients with BD were initially normal at baseline (136.0 ng/ml), but the percentage change (44.7) was significantly lower than in the patients with SLE and the controls. Baseline TFPI concentrations in patients with SLE (83.0 ng/ml) were lower than in the control group, but the TFPI response to stimulation with LMWH reached a level (626.4%) comparable to that of the controls. CONCLUSION: Depletion of the functional endothelial pool in BD and low circulating concentrations of TFPI despite an intact pool in SLE may be important in the pathogenesis of thrombosis in these vasculitic syndromes.

Familial Mediterranean fever. No role of Mycobacterium tuberculosis in ten patients.

BACKGROUND: Tuberculosis (TB) and Familial mediterranean fever (FMF) are two common diseases in our region, Turkey. Both share some properties in common: Both cause AA type amyloidosis and have association with some immunological abnormalities. Upon incidentally observing Mycobacterium tuberculosis in bone marrow biopsies of three patients with FMF in a previous study, we intended to elucidate this association prospectively. MATERIAL AND METHODS: In this study, we examined prospectively 10 FMF patients, 5 male and 5 female, with a median duration of 31 years disease activity. All were under colchicine therapy. They had no sign of renal involvement. The bone marrow biopsies of these patients were examined for the presence of M. tuberculosis by Polymerase chain reaction (PCR), BACTEC culture and pathological stains. Pathological examination was performed for the existence of granuloma and amyloid deposition by hematoxylin-eosin, Crystal Violet and Congo red stains. RESULTS: The examination of all bone marrow specimens by the mentioned methods suggest that Mycobacterium tuberculosis has no role in the ethiopathogenesis of FMF. Although the patients had a positive family history of 60% for tuberculosis and in 80% of them with positive tuberculin skin test. CONCLUSIONS: We concluded that although there seemed to be a kind of association between both diseases, this relationship is not via the direct existence of bacteria itself. Considering high family history and skin test positivity, one should look for the presence of autoimmune mechanisms under this suspicious relationship between tuberculosis and FMF. Also, this is the first study examined the state of amyloidosis in the bone marrow at an earlier stage of FMF without overt renal findings.