Behçet's disease (BD) is a chronic inflammatory disorder in which thrombosis occurs in about 30% of patients. The prothrombotic mechanisms are unknown. Thrombophilic defects and hyperhomocysteinaemia may be involved in the pathogenesis of thrombotic events, although results have been controversial. Moreover, no information is available on this issue for eastern Spain. We studied the prevalence of inherited and acquired thrombophilic risk factors in 79 patients with BD (43 men, 36 women) who had (n = 23) or did not have (n = 56) thrombosis, and in 84 healthy control subjects (42 men, 42 women). Risk factors examined were antithrombin, protein C and protein S levels, factor V Leiden, the prothrombin G20210A mutation, the methylenetetrahydrofolate reductase C677T polymorphism, and acquired thrombophilic risk factors, including anticardiolipin antibodies, lupus anticoagulant, and serum homocysteine levels. There were no differences between patients and controls in any of the parameters studied. When we studied BD patients with and without thrombotic events, the only thrombophilic defect that differed was the prothrombin G20210A mutation: Three out of 23 patients with thrombosis were carriers, compared with none of 56 patients without thrombosis (p = 0.022). Two of the three carriers developed catastrophic or recurrent thrombotic episodes; one was a homozygous carrier of the G20210A prothrombin mutation and the other was doubly heterozygous for the G20210A prothrombin mutation and factor V Leiden. A meta-analysis demonstrated an association of factor V Leiden and prothrombin mutation with thrombosis in BD. When studies from Turkey were excluded from the meta-analysis, only the prothrombin G20210A mutation was associated with thrombosis.

Behçet's disease (BD) is a chronic inflammatory disorder in which thrombosis and posterior ocular involvement occur in about 30% of patients, whose ethiology is unknown. It has not been established whether mean platelet volume (MPV), a marker of platelet activation, is involved in the pathogenesis of thrombotic events and posterior uveitis in these patients. We aimed to analyze whether there are differences in MPV in BD patients when compared with controls and its relation with the presence of thrombosis and posterior uveitis. We determined MPV and platelet count, along with Creactive protein (CRP) and cardiovascular risk factors (because of their influence on MPV) in 89 BD patients (of which 24 had thrombosis and 23 had posterior uveitis) and 89 sex-and age-matched healthy controls. BD patients showed statistically higher MPV than controls: 10.98 ± 1.19 fL vs. 10.60 ± 1.21 fL (P = 0.044) and higher CRP: 5.9 ± 8.9 mg/L vs. 1.4 ± 1.7 mg/L (P = 0.001). The percentage of hyperlipemia and diabetes was higher in cases than in controls (P = 0.032, P = 0.013, respectively). No differences in MPV were observed when comparing: patients with and without thrombosis: 11.8 ± 1.27 fL vs. 10.94 ± 1.28 fL (P = 0.654); with and without posterior uveitis: 10.76 ± 1.18 fL vs. 11.03 ± 1.30 fL P = 0.398; with CRP and cardiovascular risk factors (P > 0.05). MPV correlated negatively with platelet count (r = -308, P < 0.01), but not with CRP (r = -0.22, P = 0.772). MPV seems to relate to neither thrombosis nor posterior uveitis in BD patients.

SummaryBehçet's disease is a multi-systemic inflammatory disorder of unknown cause. Most abnormalities have been associated with endothelial injury caused by vasculitis. Thrombosis occurs in about 25% of patients, although the mechanism is unknown. The objective of this study was to evaluate the protein C activation system in Behçet's disease and its correlation with venous thromboembolism (VTE). Thirty-nine patients (12 with VTE) and 78 age-and sex-matched controls were included in the study, and levels of protein C, protein S, activated protein C (APC), protein C inhibitor (PCI), soluble thrombomodulin (TM), antithrombin (AT), a 1 -antitrypsin, fibrinogen, factor VIII, von Willebrand factor (VWF) and C-reactive protein (CRP) were measured. APC and TM levels were significantly lower in patients than in controls, whereas protein S, AT, a 1 -antitrypsin, fibrinogen, factor VIII, VWF and CRP levels were significantly higher in patients than in controls. APC, PCI and TM levels were lower in patients with VTE (0AE65 ± 0AE19 ng/ml, 86% ± 22% and 15AE5 ± 7AE1 ng/ml respectively) than in those without VTE (0AE78 ± 0AE17 ng/ml, 100% ± 15% and 22AE1 ± 15AE3 ng/ml) (P < 0AE05). In patients, APC levels below 0AE75 ng/ml (10th percentile of the control group) increased the risk of VTE about fivefold (odds ratio ¼ 5AE1; 95% confidence interval ¼ 1AE1-23AE4). These results show that reduced APC levels are associated with the high incidence of VTE in Behçet's disease.

Psoriasis patients show elevated CECs and MPs, as a sign of endothelial dysfunction, which correlates with inflammatory markers as well as subclinical atherosclerosis and some capillaroscopy findings.

Red blood cell distribution width (RDW) has been shown to be associated with disease activity in several inflammatory disorders. However only one study to show this has been conducted in patients with Behçet's disease (BD).The aim of the present study was to analyse the association of RDW with BD and its main complications; i.e.; thrombosis and posterior uveitis. A second aim was to analyse the possible correlation between RDW and both haematological and inflammatory parameters.Eighty-nine patients with BD (48 males/41 females) and 94 controls (49 males/45 females) were included in the study. Patients were in an inactive phase of the disease, showing only minimum activity. RDW was statistically higher in patients than in controls (14.02 ± 1.32 vs. 13.15 ± 0.75; p < 0.001) as were CRP, fibrinogen, leucocytes and neutrophils (p < 0.001). No differences in haematimetric indices (MCV, MCH, MCHC) were observed (p > 0.05). RDW correlated negatively with haemoglobin, MCH and MCHC (p < 0.05), and directly with homocysteine (p < 0.01). No correlation was found between RDW and the several inflammatory parameters analysed (p > 0.05). The multivariate regression analysis revealed that haemoglobin and homocysteine were independent predictors of RDW (beta coefficient: −0.310; p = 0.003, beta coefficient: 0.379; p < 0.001, respectively). RDW >14 was associated with neither thrombosis nor uveitis (p = 0.935; p = 0.553, respectively).Our results indicate that BD patients show increased RDW when compared with controls. This increase seems to be related with haematimetric indices and with homocysteine levels. Lack of correlation with inflammatory markers may be due to the fact that patients were in an inactive phase of the disease.