Impaired prostacyclin synthesis by vessel walls in Behçet's disease

An update on the use of biologic therapies in the management of uveitis in Behçet's disease: a comprehensive review

ᅟ: Behçet's disease (BD) is a systemic vasculitis characterised by a relapsing remitting course, affecting multiple organ systems. In the eye, it is a cause of potentially blinding inflammation in the form of uveitis. Management of uveitis in BD often requires the use of systemic immunosuppression, in order to reduce disease activity and prevent accumulation of irreversible damage. Whilst corticosteroids remain the mainstay of treatment, long-term use is limited by the development of adrenocorticotrophic side effects. There has therefore been significant interest in the use of corticosteroid-sparing immunosuppressive agents, and more recently, biologic therapies. Recent publications have demonstrated biologic therapy to have beneficial effects both on overall disease control, and quality of life for patients with BD. Widespread use of such agents is however limited, partly by the lack of high quality research evidence, and partly by the prohibitive cost of biologic treatments. In this review, we discuss the most recent research investigating the use of biologic therapy in uveitis due to BD, with consideration of health economics and quality of life outcomes.

Common FMF alleles may predispose to development of Behcet's disease with increased risk for venous thrombosis

BACKGROUND

Behcet's disease (BD) is an inflammatory disorder of unknown cause, associated with vasculitis. Arterial or venous thrombosis occurs in about 25% of BD patients. Familial Mediterranean fever (FMF) is another inflammatory disorder, which stems from mutations in the FMF gene (MEFV) and shares a number of features with BD.

OBJECTIVE

MEFV analysis in patients with BD suggests that mutated MEFV may act as a susceptibility gene in BD. We studied the rate and the clinical correlates of MEFV mutations in Israeli BD patients.

METHODS

Included were 54 BD patients who satisfied the International Study Group criteria for BD. All BD patients were genotyped using polymerase chain reaction (PCR) and restriction enzyme analysis for the three most common MEFV mutations (M694V, V726A, and E148Q). The association between BD manifestations and MEFV alleles was analysed.

RESULTS

Twenty-one BD patients were found to carry a single MEFV mutation and three additional patients were compound heterozygotes, a frequency significantly higher than that expected for ethnically matched healthy individuals. There were no statistically significant differences between carriers and non-carriers with respect to gender, frequency of HLA B5 antigen, cutaneous lesions, joint disease, and severity score. However, carriers did experience thrombosis more often [54% vs. 17%, p<0.005, odds ratio (OR) = 6.9, 95% confidence interval (CI) 1.75-26.9] and uveitis less often (20% vs. 40%, p<0.05, OR = 0.2, 95% CI 0.04-0.92).

CONCLUSIONS

MEFV appears to be a susceptibility and modifier gene in BD.

Caspase-9 expression is increased in endothelial cells of active Behçet's disease patients

BACKGROUND

Behçet's disease is a multisystem disease of unknown etiology. Caspase-9 is responsible for initiating the caspase activation cascade during apoptosis. The aim of this study was to examine caspase-9 expression in both endothelial and perivascular infiltrates of patients with active Behçet's disease.

METHODS

Fifteen patients with active Behçet's disease, attending the First Dermatology Department, Ankara Numune Hospital, Ankara, Turkey between June 2003 and December 2005, were included in the study. Oral biopsy specimens from nine healthy volunteers were taken as the healthy control group, and skin biopsies from 18 psoriasis patients were used as the inflammatory control group. The specimens were examined with caspase-9 primary antibody. Statistical analyses were performed using SPSS 11.5.

RESULTS

The mean caspase-9-positive endothelial cell counts were 7.17 +/- 2.45 in active Behçet's disease, 4.81 +/- 0.76 in healthy controls, and 4.35 +/- 1.34 in inflammatory controls. The difference between Behçet's disease and healthy controls was statistically significant, with increased endothelial staining in active Behçet's disease (P = 0.049). The difference between Behçet's disease and inflammatory controls was also statistically significant; the rate of staining was higher in Behçet's disease (P = 0.006). The mean caspase-9-positive dermal perivascular cell counts were 5.15 +/- 2.32 in Behçet's disease, 3.32 +/- 0.82 in healthy controls, and 5.54 +/- 4.95 in inflammatory controls. These values did not show any statistically significant difference (P = 0.407).

CONCLUSION

Endothelial cells are one of the key cells in Behçet's disease, and our findings support the role of endothelial cells in the etiopathogenesis of Behçet's disease.

Peripheral insulin resistance in patients with Behcet's disease

In this study, we examined peripheral insulin resistance in patients with Behçet's disease (BD) characterized by chronic inflammation and endothelial dysfunction. Fourteen patients with BD and 15 healthy controls were recruited to the study. Insulin resistance was investigated by the hyperinsulinaemic-euglycaemic glucose clamp technique. BD patients displayed an enhanced rate of insulin resistance compared to healthy controls (P = 0.014). The insulin sensitivity (M), measured as the glucose utilization rate under steady-state conditions of euglycaemia, was significantly decreased (P = 0.001) in BD patients compared to the controls (4.09 +/- 0.16 vs. 5.60 +/- 0.27 mg/kg/min). The C-reactive protein (CRP) level, but not the erythrocyte sedimentation rate (ESR), was significantly related to the presence of insulin resistance (CRP: r(s) = 0.589, P = 0.27; ESR: r(s) = 0444, P = 0112), whereas no relationship was found between the M-value and ESR or CRP. We conclude that patients with BD exhibit peripheral insulin resistance; this could be explained as the diverse consequences of inflammation and endothelial dysfunction in BD.

Factor V Leiden and prothrombin gene G20210A mutations in Italian patients with Behçet's disease and deep vein thrombosis

OBJECTIVE

To evaluate the frequency and type of vascular lesions and to study the association of factor V gene G1691A (Leiden) and prothrombin gene G20210A polymorphisms with venous thrombosis in Italian patients with Behçet's disease (BD).

METHODS

Included were 118 consecutive Italian BD patients followed over a 3-year period (1997-1999) who satisfied the International Study Group criteria for BD. The control group consisted of 132 healthy Italian blood donors. All BD patients and controls were genotyped by polymerase chain reaction and allele-specific restriction enzyme techniques for factor V Leiden and prothrombin gene G20210A polymorphisms.

RESULTS

Vascular lesions were observed in 37 (31.4%) patients. The 2 most common lesions were subcutaneous thrombophlebitis (10.2%) and deep vein thrombosis (DVT) of the legs (22.8%). No significant demographic and clinical differences between patients with and without DVT were present. The distribution of allele and genotype frequencies of prothrombin gene G20210A and factor V Leiden polymorphisms did not differ significantly between BD patients and healthy controls. The frequencies of carriage rates of prothrombin gene G20210A and factor V Leiden polymorphisms in BD patients with and without DVT were similar. However, the frequency of 20210A allele was significantly higher in BD patients with ocular disease than in those without, particularly in the patients with posterior uveitis/retinal vasculitis.

CONCLUSIONS

The frequency and types of vascular lesions in Italian BD patients were similar to those reported in studies from other countries. No association between factor V Leiden mutation and G20210A mutation in the 3'-untranslated region of the prothrombin gene with DVT was found. However, a prothrombin gene G20210A mutation may influence the development and severity of ocular involvement in BD.

Pathogenesis of Adamantiades-Behçet's disease

The aetiology of Adamantiades-Behçet's disease remains unknown and its pathogenesis is not fully understood. Linked intrinsic and extrinsic factors are thought to contribute to the development of the disease, which probably occurs by environmental triggering of a genetically determined disorder. Transmission is solely vertical, indicating that the disease is not contagious. Genetic factors have been investigated and a significant link of HLA-B51, especially of HLA-B5101, has been identified. However, none of the functional correlates of the disease appear to be restricted by HLA-B51. Recently, the role of the genes encoding TNF, Tap proteins and MICA has been emphasised. Extrinsic pathogenetic candidates have been identified, including bacterial ( Streptococcus sanguis, Mycoplasma fermentas) and viral (human herpes virus) antigens and environmental pollution, which may cross-react with oral mucosal antigens and induce immunological mechanisms. A common factor linking some of the possible pathogenetic agents is extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant Th1 cell responses. Neutrophils may also play a role in the pathogenesis of the disease, as they are attracted by macrophages and activated endothelial cells, which release cytokines and chemokines (especially IL-8) at the site of the lesions, and thus contribute to tissue damage and self maintenance of inflammation. Endothelial activation leading to a chronic local inflammation process together with platelet and serum factors enhance coagulation and thrombosis.

Association of class I HLA antigens with the clinical manifestations of Turkish patients with Behçet's disease

Genetic factors appear to be important in the pathogenesis of Behçet's disease. Although it is known to be strongly associated with HLA-B 51, the association of HLA class I antigens with specific clinical findings of the disease has not been studied extensively and the few studies are conflicting. The aim of this study was to investigate the association of HLA class I alleles with the manifestations of Behçet's disease in Turkish patients. Eighty-five patients with Behçet's disease were typed for HLA-A, B, and C antigens with the serologic, standard microlymphocytotoxicity technique. Possible associations of the HLA complex with clinical findings of Behçet's disease were examined. Statistically significant findings are as follows (P < 0.05): increased HLA-B 51 and decreased HLA-B35 frequency in patients with thrombophlebitis, increased HLA-A29 and decreased HLA-Bw6 frequency in patients with ocular involvement, decreased HLA-Cw2 frequency in patients with erythema nodosum, and decreased HLA-Cw 7 frequency in patients with genital ulceration. Of particular note, the results of this study suggest that the presence of HLA-B 51 and the absence of HLA-B35 can be regarded as laboratory risk factors of venous thrombosis in patients with Behçet's disease.

The multiple faces of Behçet's disease and its aetiological factors

Behçet's disease (BD) is a chronic, inflammatory multisystemic condition of unknown aetiology. It is clinically characterized by recurrent orogenital ulcerations and skin eruptions; ocular manifestations; arthritis; vasculitis and in some cases neurological and large vessel involvement. Aetiology has not been defined, but genetic, environmental, viral, bacterial and immunological factors have been proposed as causative agents. Treatment includes colchicine, thalidomide, steroids and immunosuppressive agents and it is based on the severity of systemic manifestations, such as central nervous system involvement, arterial aneurysms and thrombosis of the major veins. Mortality is related to major system involvement. In this article the different clinical features, the multiple faces of BD and a list of currently suspected aetiological factors of the disease are discussed, and treatment modalities summarized.

Behçet's disease

Behçet's disease is a systemic vasculitis of unknown aetiology characteristically affecting venules. Onset is typically in young adults with recurrent oral and genital ulceration, uveitis, skin manifestations, arthritis, neurological involvement, and a tendency to thrombosis. It has a worldwide distribution but is prevalent in Japan, the Middle East, and some Mediterranean countries. International diagnostic criteria have been proposed, however diagnosis can be problematical, particularly if the typical ulcers are not obvious at presentation. Treatment is challenging, must be tailored to the pattern of organ involvement for each patient and often requires combination therapies.

Arterial thrombosis leading to intestinal infarction in a patient with Behçet's disease associated with protein C deficiency

Behçet's disease may be a possible cause of both occlusive and aneurysmal arterial involvement as well as recurrent venous thrombosis. A case of Behçet's disease complicated with vascular involvement leading to intestinal infarction is presented. A 41-yr-old man suffering from Behçet's disease for 15 yr presented with a 2-day history of severe abdominal pain and bloody diarrhea. Intestinal infarction secondary to thrombosis of the superior mesenteric artery had been diagnosed during surgical exploration 3 yr previously. He was started on anticoagulation with nutritional support. The patient was readmitted with severe diarrhea and malabsorption symptoms 3 yr after intestinal resection. A thrombus located in the posterior wall of the infrarenal portion of aorta was detected by aortography and ultrasonography. Although thrombosis is a relatively common complication of Behçet's disease caused by vasculitis, protein C deficiency, which is a pertinent laboratory finding in this case, might be a secondary factor in the thrombotic event. This is the first case reported of mesenteric artery thrombosis leading to bowel infarction and abdominal aorta thrombosis associated with protein C deficiency.

Does hepatic vein outflow obstruction contribute to the pathogenesis of hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is one of the more common malignant diseases in the world. Here we have investigated role of hepatic venous outflow obstruction in the development of HCC. During a 10-year period from November 1986 to December 1996, 1,748 patients with clinical evidence of either portal hypertension, hepatic venous outflow obstruction, or inferior vena cava obstruction without Behçet's disease (BD) and 512 patients with Behçet's disease were examined at Hacettepe University Hospital. The presence of and the effect of hepatic venous obstruction on the subsequent development of HCC was assessed. In each case, hepatic vein thrombosis was assessed by hepatic venography and by digital subtraction angiography (DSA), computed tomography (CT), ultrasonography (US), and liver biopsy. Coagulation factors, including protein C, protein S, anti-thrombin III, and routine laboratory studies assessing the coagulability of blood were also investigated. The role of hepatic venous outflow obstruction on the subsequent development of HCC was determined by periodic laboratory investigations that included alpha-fetoprotein (AFP), ultrasonography, and when indicated liver biopsy. During the same time period all patients diagnosed as having HCC were investigated to identify all potential etiologic factors responsible for the HCC. Fifty-five (10.7%) of the 512 patients with BD were found to have one or more large vein thromboses. Sixteen of these 55 (29%) patients had hepatic vein thrombosis. During the follow-up period HCC developed in 2 of these 16 patients (12.5%), 34 and 21 months after a diagnosis of hepatic vein thrombosis was established. Forty patients from a total of 1,748 patients with clinical evidence of portal hypertension and cirrhosis, but without BD, were found to have evidence of hepatic vein thrombosis. Twenty-one of these 40 patients had an identifiable underlying disorder responsible for their hepatic vein thrombosis. Despite a full clinical and laboratory investigation in the other 19 patients, the etiologic factor responsible for the hepatic vein thrombosis remained obscure. Only one of these 19 patients, who also had portal vein thrombosis, developed HCC during a 9-year follow-up. Thus, a total of three of the 56 (5.36%) of cases of hepatic vein thrombosis developed an HCC. All of the hepatic tumors were of the multicentric, nodular, rapidly growing type. Despite the presence of hepatic vein thrombosis, there was no clear-cut histologic evidence for cirrhosis. Our experience suggests that hepatic vein thrombosis may be a contributing factor responsible for HCC development. Moreover, we advise that individuals with hepatic vein thrombosis should be assessed periodically for the development of HCC.

Thrombotic syndromes and autoimmune diseases

Maintenance of blood flow involves the dynamic interactions between the endothelium, circulating cellular components, coagulation factors, and factors involved in fibrinolysis. Autoantibodies, inflammatory cytokines and other undefined triggers in a genetically predisposed person may lead to an imbalance in the equilibrium between the various hemostatic pathways resulting in potentially catastrophic thrombotic events. This article reviews the clinical manifestations and treatment of selected, potentially life-threatening thrombotic syndromes that may occur in association with autoimmune diseases. Special mention is made of thrombotic events associated with Behçet's syndrome.

Bilateral central retinal vein thrombosis in Behçet's disease

Behçet's disease is a multisystem disorder affecting the skin, mucous membranes, eye, joints, central nervous system, and blood vessels. One of the known vascular complications of Behçet's disease is venous thrombosis or aneurysm formation. We report, herewith, a patient with Behçet's disease who developed radial artery aneurysm, deep venous thrombosis, and bilateral central retinal vein thrombosis. To our knowledge, this is the first report of bilateral central retinal vein thrombosis in association with Behçet's disease.

Anti-endothelial cell antibodies, endothelial proliferation and von Willebrand factor antigen in Behçet's disease

Endothelial cell dysfunction has previously been demonstrated in Behçet's disease which has vasculitic features. In this study we investigated anti-endothelial cell antibodies (AECA) and von Willebrand factor antigen (vWF) levels in patients with Behçet's disease. In vitro effects of patient sera on endothelial cell proliferation were also evaluated. AECAs were present in 29% of 70 Behçet's disease patients (Binding Index: 25 +/- 29% vs 9 +/- 7% in normal controls, p < 0.005). 95% of AECA positive patients were clinically active compared to 74% of AECA negative patients (p = 0.04). Among specific organ manifestations only active arthritis correlated with AECA positivity (6 of 7 patients vs 14 of 63, p = 0.002). AECA positive patients had a significantly higher mean ESR (37 +/- 24 mm/h vs 21 +/- 17 mm/h, p:0.006). Mean vWF levels were also significantly higher in patients compared to controls (166 +/- 75% vs 84 +/- 34%, p < 0.0001). No correlations were observed between AECA titres and vWF levels. No significant differences were observed between patients and controls when endothelial cell proliferation was studied (Proliferation Index: 1.25 +/- 0.28 vs 1.12 +/- 0.25, p = 0.5). Our results suggest that AECA may be related to disease activity in Behçet's disease. The presence of vWF, even in patients in complete remission, might be related to factors other than endothelial damage for vWF release from endothelial cells.

Behçet's syndrome and factor XII deficiency

Several mechanisms have been proposed to explain thrombotic tendency in Behçet's syndrome. We report the case of a 43-year old woman presenting retinal-vein thrombosis, factor XII deficiency and Behçet's syndrome. This kind of association has thus far never been reported. Factor XII deficiency is known to possibly induce various types of thrombosis and might explain the prevalence of ocular symptoms in our patient.

Treatment of Behçet disease with indomethacin

Thirty patients with Behçet disease (BD) were treated with oral indomethacin 25 mg four times daily for 3 months as an open label study. The study population consisted of 13 women and 17 men from 15 to 45 years of age (mean 27 years). At the initiation of the therapy, 28 patients had oral aphthous lesions, 23 had joint involvement, 13 had genital ulcerations, 8 had cutaneous lesions, and 4 had eye involvement. Eighty-eight percent of patients with skin lesions, 80% with joint involvement, 43% with oral aphthous lesions, and 38% with genital ulcerations responded to indomethacin therapy. In three patients indomethacin was changed to the suppository form due to gastrointestinal side effects. Although it is difficult to assess the efficacy of indomethacin in BD because of the intermittent nature of symptoms, the majority of patients showed improvement in their symptoms of arthritis and skin lesions. This study indicates that indomethacin can be used as effective therapy particularly in patients with joint involvement.

Prostanoid production in varicose veins: evidence for decreased prostacyclin with increased thromboxane A2 and prostaglandin E2 formation

In this study, formation of arachidonic acid-derived prostanoids was investigated in saphenous veins of varicosed and nonvaricosed patients, all undergoing saphenectomy respectively for varicosis or in preparation for coronary bypass operation. Venous production of prostacyclin (PGI2), thromboxane A2 (TXA2) and prostaglandin E2 (PGE2) was assessed by bioassay and/or radioimmunologic assays as appropriate. Fragments of saphenous veins from varicosed patients produced significantly less PGI2 and more TXA2 and PGE2 than those from the control patients. Addition of arachidonic acid to incubation mixtures dose dependently increased release of these prostanoids, but the levels of PGI2 produced were consistently lower in veins from varicosed patients. No differences were found in varicosed patients between various segments of the same vein, no matter whether macroscopically affected or unaffected. These results demonstrate that the cyclooxygenase pathway in the venous wall of subjects with varicosis is shifted toward lesser formation of PGI2 and higher production of proaggregatory and proinflammatory prostanoids such as PGE2 and TXA2. These biochemical changes may be relevant to inflammation and thrombogenesis in varicosis.

Vasculitis of breast in Behçet's disease--a case report

This is the case report of a thirty-one-year-old woman who presented with a large skin lesion on a breast that was first thought to be a malignant or inflammatory process. After a biopsy, the lesion was diagnosed as nonspecific vasculitis. No similar case has been found in a review of the literature.

Decreased prostacyclin sensitivity of platelets in patients with Behçet's syndrome

Patients with Behçet's syndrome have an increased risk of arterial and venous thrombosis, and abnormal platelet function has been implicated. Platelet function was studied in nine patients with Behçet's syndrome and in nine age- and sex-matched healthy volunteers. Platelet aggregation in response to ADP was measured, and the threshold concentration required to produce irreversible aggregation determined. Sensitivity of platelets to the inhibitory effect of prostacyclin was also determined. In addition, plasma levels of the platelet-specific proteins, beta-thromboglobulin and platelet factor 4, and stimulated platelet thromboxane B2 production, were measured. Platelets from patients with Behçet's syndrome showed normal aggregation in response to ADP, irrespective of disease activity. Platelet sensitivity to prostacyclin was, however, decreased compared with controls--with a mean prostacyclin ID50 of 5.5 +/- 1.3 ng ml-1 (mean +/- SEM) and 1.9 +/- 0.3 ng ml-1, respectively (P less than 0.01). This reduction in platelet sensitivity to prostacyclin was greatest in patients with the most active disease. These results suggest that Behçet's syndrome may be associated with altered platelet function, and this may have important consequences with regard to the increased risk of thrombosis associated with this condition.