Apremilast: A Review in Oral Ulcers of Behçet's Disease.

The oral phosphodiesterase 4 inhibitor apremilast (Otezla®) is indicated for the treatment of oral ulcers associated with Behçet's disease in some countries, including the USA (where it is the first agent approved for the disease) and Japan. In phase 2 and 3 trials in adults with this chronic and debilitating disorder, 12 weeks of treatment with apremilast 30 mg twice daily reduced the number and pain of oral ulcers and disease activity relative to placebo, with these clinical benefits being accompanied by improvements in health-related quality of life (HR-QOL). Benefits of apremilast were seen regardless of baseline patient/disease characteristics and in Japanese patients, and were sustained over up to 64 weeks of treatment. Apremilast was generally well tolerated, with gastrointestinal adverse events being among the most common tolerability issues. Emerging real-world data also support the drug's use in this setting. Thus, for patients with oral ulcers associated with Behçet's disease, apremilast provides an effective and generally well tolerated approved treatment option.

Paraoxonase and Arylesterase Levels in Behcet's Disease and Their Relations with the Disease Activity.

The aim of this study was to determine the paraoxonase (PON) and arylesterase (ARE) enzyme activity levels in Behcet's disease (BD) and to investigate whether they are associated with the disease activity. Twenty-six patients (study group) with active BD and 28 healthy controls (control group) were included in this study. While the patients who had at least one of the symptoms related to genital ulcer, skin lesions, active uveitis, arthritis, thrombophlebitis, or central nervous system involvement in addition to oral ulcers were considered as the active group, the patients who did not show clinical symptoms in the last one month due to the medical treatment were considered as the inactive group in the clinical evaluation of patients with BD. The PON and ARE levels were found to be significantly lower in the study group than the control group (p < 0.05). The PON levels of the active and inactive groups were 96.23 ± 57.84 and 112.2 ± 65.14, respectively. The ARE levels of the active and inactive groups were 30.49 ± 5.81 and 30.85 ± 6.40, respectively. No significant correlations were found between clinical findings and the activity levels of PON and ARE in the active patient group (p > 0.05). The activities of the antioxidant PON and ARE enzymes are reduced in BD. Therefore, it may be useful to add antioxidant therapy to the conventional treatment of the disease.

Carbonic anhydrase I and II autoantibodies in Behçet's disease.

BACKGROUND: Behçet's disease is a vasculitis, seen more frequently around the Mediterranean and the Far East, and evinces with oral and genital ulcerations, skin lesions and uveitis. Carbonic anhydrase (CA) is a metalloenzyme which is widely distributed in the living world, and it is essential for the regulation of acid-base balance. Anti-CA antibodies have been reported in many disorders, such as systemic lupus erythematosus, Sjögren's syndrome, rheumatoid arthritis, endometriosis, idiopathic chronic pancreatitis, type 1 diabetes and Graves' disease. The goal of this study was to investigate CA I and II autoantibodies in Behçet's disease (BD). METHODS: 35 patients with BD and 29 healthy controls were included in the study and CA I and II autoantibody levels were investigated by ELISA. RESULTS: The CA I and II autoantibody levels of BD group were significantly higher than the healthy group (p=0.013, p inf 0.0001, respectively). A cut-off value of 0.250 ABSU for anti-CA I was associated with 34 % sensitivity and 100 % specificity and a cut-off value of 0.171 ABSU for anti-CA II was associated with 54 % sensitivity and 100 % specificity for predicting BD. CONCLUSION: The CA I and II autoantibody levels in patients with BD were found higher compared to control group and the results suggest that CA I and II autoantibodies may be involved in the pathogenesis of BD.

Serum anti-lysozyme is associated with disease activity of Behçet's disease.

OBJECTIVES: We investigated the association between autoantibodies against non-myeloperoxidase (MPO) neutrophil granule antigens and activity of Behçet's disease (BD). METHODS: We consecutively enrolled 51 BD patients. We assessed clinical data and BD activity using patients' index scores from the Behçet's Disease Current Activity Form and we performed tests for antibodies against proteinase 3 (PR3), MPO, bactericidal permeability increasing protein (BPI), cathepsin G, elastase, lactoferrin and lysozyme. RESULTS: The median patient index score was 2.0, and 56.9% of patients had active BD. In multivariate analysis of variables with significant correlations, only anti-lysozyme showed a significant correlation with BD activity (P = 0.002). In multivariate logistic regression analyses of variables, when patients were classified into groups according to the optimal cutoff levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and anti-lysozyme (ESR > 42.5 mm/h, CRP > 1.35 mg/L and anti-lysozyme > 2.95 IU/mL), the variable with independent predictive value was anti-lysozyme (odds ratio 8.384, P = 0.015). CONCLUSION: Anti-lysozyme was significantly correlated with disease activity score and it was the only independent value to predict active disease in patients with BD. Furthermore, patients having anti-lysozyme levels ≥ 2.95 IU/mL had a significantly higher risk of having active BD than those who did not.

Decreased Activity and Genetic Polymorphisms of CYP2C19 in Behçet's Disease.

Behçet's disease (BD) is a systemic autoimmune disorder. Cytochrome P450 enzymes (CYPs) are responsible for various drug metabolism reactions as well as those of endogenous substances which may be associated with autoimmune disease susceptibility. Recently, we reported that in patients with BD, CYP2C9 seems to be down-regulated due to inflammation. In the same Turkish patients with BD, we investigated whether also CYP2C19 activity is decreased. Lansoprazole (30 mg) was given as a probe drug to evaluate CYP2C19 activity in 59 patients with BD and 27 healthy control volunteers. An HPLC method was used to determine plasma lansoprazole and its metabolite, 5-hydroxy lansoprazole, concentrations. The genotyping for CYP2C19 *2, *3 and *17 polymorphisms was made using PCR-RFLP. The median lansoprazole/5-hydroxy lansoprazole metabolic ratio (MR) in patients with BD was 2.6-fold higher as compared to the healthy control group (p = 0.001, 22.6 (1.3-26) and 8.8 (0.5-140) as median and range, respectively). The CYP2C19*17*17 genotype frequency was found to be significantly less in the BD group as compared to the healthy controls (1.7% versus 14.8% in controls, p = 0.01). Additionally, colchicine treatment did not affect the CYP2C19 enzyme activity in six patients (p = 0.43). In conclusion, the patients with BD had lower CYP2C19 enzyme activity and lower frequency of the CYP2C19*17 allele as compared to those of the healthy controls. Further studies are warranted on the mechanisms underlying this relation. This study should also be applied to other autoimmune diseases similarly characterized by local or systemic inflammation.

Association of Reduced Heme Oxygenase-1 with Decreased MicroRNA-196a2 Expression in Peripheral Blood Mononuclear Cells of Patients with Intestinal Behcet's Disease.

AIMS: To examine the expression of miRNAs and mRNAs of heme oxygenase 1 (HO-1) in patients with active intestinal Behcet's disease (BD). METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from BD patients with active ileocecal ulcers or from healthy donors. Expression levels of four miRNAs were studied using real-time PCR. The levels of mRNAs of ho-1, bach1, and CD14 were measured by qRT-PCR. Serum levels of cytokines were analyzed by ELISA. RESULTS: Among four miRNAs, only levels of miR-196a2 were significantly decreased from BD patients with active ileocecal ulcers as compared with healthy controls. Moreover, level of mRNA ho-1 expression in PBMCs from patients with BD was reduced. No significant difference on bach1 and CD14 mRNA levels was observed. Levels of IFN-γ, IL-17, IL-10, IL-1ß, and TNF-α were higher in patients with active intestinal BD than those in healthy controls. CONCLUSION: The present results suggest that miR-196a2 expression is decreased in active intestinal BD patients. Down regulated miR-196a2 may be involved in intestinal BD pathogenesis by targeting Bach1/ho-1. Consequently, pro-inflammatory cytokines are closely implicated in the evolution of intestinal BD.

PTPN22 is not associated with Behçet's disease. Study spanning the complete gene region in the Spanish population and meta-analysis of the functional variant R620W.

OBJECTIVES: The functional variant R620W of the protein tyrosine phosphatase non receptor-22 (PTPN22) gene plays an important role in susceptibility to several immuno-mediated pathologies. Behçet's disease (BD) is a complex disease related to the immune system with a demonstrated genetic base. The HLA class I genes are the most important genetic factors in BD although other genes are also involved in the susceptibility to this disease. The PTPN22 has been proposed as a candidate gene in BD but this association has not been clearly demonstrated yet. The aim of this study was to assess the association of PTPN22 with BD. METHODS: A cohort composed of 404 Spanish BD patients and 1517 unrelated healthy individuals ethnically matched was genotyped in rs2476601 (R620W). Five tag SNPs: rs1217412, rs2476599, rs3789607, rs3765598 and rs1217419 (spanning a 57 Kb region between 3'UTR and 5'UTR) and rs2488457 (located at the promoter region) were also studied in order to perform a screening of the complete gene. Genotyping was performed using TaqMan® assays. The rs2476601 data were included in a meta-analysis together with those published till the date. The rest of SNPs were used in a case-control study. RESULTS: No evidence of the association of rs2476601 with BD in the meta-analysis (P = 0.504 in the model of alleles) was found. In the case-control study, no statistically significant differences were observed when comparing the distribution of variants in patients and controls. CONCLUSIONS: Our results do not support a major role of the PTPN22 gene in BD.

The serum angiotensin converting enzyme and lysozyme levels in patients with ocular involvement of autoimmune and infectious diseases.

BACKGROUND: Increased serum levels of angiotensin converting enzyme and lysozyme are considered as inflammatory markers for diagnosis of sarcoidosis which is an autoimmune inflammatory disease. The purpose of this study is to evaluate the significance of differences in serum angiotensin converting enzyme and lysozyme levels of patients with ocular involvement of other autoimmune inflammatory and infectious diseases. METHODS: This is a prospective study involving patients with ankylosing spondylitis, behcet's disease, presumed sarcoidosis, presumed latent tuberculosis, presumed latent syphilis, and control group. The serum levels of angiotensin converting enzyme and lysozyme were analyzed by enzyme-linked immunosorbent assay. Bonnferoni analysis was used to assess pairwise comparisons between the groups. RESULTS: There was a significant increase in serum angiotensin converting enzyme level in patients with presumed sarcoidosis compared to ankylosing spondylitis (p = 0.0001), behcet's disease (p = 0.0001), presumed latent tuberculosis (p = 0.0001), presumed latent syphilis (p = 0.0001), and control group (p = 0.0001). The increase in serum lysozyme level was significant for patients with presumed sarcoidosis with respect to ankylosing spondylitis (p = 0.0001), behcet's disease, (p = 0.0001) presumed latent tuberculosis (p = 0.001), presumed latent syphilis (p = 0.033), and control group (p = 0.0001). CONCLUSION: Elevated serum angiotensin converting enzyme levels are significant for patients with presumed sarcoidosis compared to ocular involvement of other autoimmune diseases such as behcet's disease and ankylosing spondylitis, and ocular involvement of infectious diseases such as presumed latent tuberculosis and presumed latent syphilis. However, elevated serum lysozyme level might be also detected in ocular involvement of infectious diseases such as presumed latent tuberculosis and presumed latent syphilis. TRIAL REGISTRATION NUMBER: NCT02627209. Date of registration: 12/09/2015.

Plasma thiopurine S-methyltransferase levels and azathioprine-related adverse events in patients with Behçet's disease.

OBJECTIVES: Thiopurine S-methyltransferase (TPMT) is the key enzyme inactivating azathioprine (AZA), an immunosuppressive agent commonly used for treating inflammatory diseases including Behçet's disease (BD), systemic lupus erythematosus (SLE) and systemic vasculitis. Low TPMT levels facilitate occurrence of AZA-related adverse effects. We investigated TPMT levels in patients with BD, compared to healthy controls and patients with SLE or systemic vasculitis. METHODS: This cross-sectional study included 101 BD (77 using AZA), 74 SLE (35 using AZA), and 44 vasculitis (18 using AZA) patients and 101 healthy controls. Plasma TPMT levels were measured using ELISA. Student's t- and Kruskal-Wallis tests were used to compare TPMT levels according to possible risk factors. Receiver operating characteristic (ROC) analysis was used to determine whether a cut-off TPMT level could be found to predict AZA-related adverse effects. RESULTS: Plasma TPMT levels (mean± SD ng/mL) in BD (22.80±13.81) were comparable with healthy controls (22.71±13.49), but significantly lower than in SLE group (29.37±11.39) (p<0.001). TPMT levels in 130 patients receiving AZA were similar to the rest of the group. AZA-related adverse effects were identified in only 8 patients (5 with BD and 3 with SLE). TPMT levels were significantly lower in those 8 patients (14.08±9.49 vs. 25.62±12.68) (p=0.013), besides a cut-off value for predicting adverse effects was determined for the BD group with ROC analysis (area under the curve: 0.813). CONCLUSIONS: This is the first study to evaluate TPMT activity in a Turkish adult population. Although low plasma TPMT level is not the only factor determining AZA toxicity, a TPMT cut-off value may help to predict AZA-related adverse effects in BD.

Lack of association of TNFAIP3 and JAK1 with Behçet's disease in the European population.

OBJECTIVES: Behçet's disease (BD) is an immune-mediated and complex disease which has been associated with HLA class I molecules although other genes such as IL23R and IL10 have also been involved in the susceptibility to BD. Recently, an association of variants of the JAK1 and TNFAIP3 genes with the disease has been reported in the Chinese Han population. The aim of the present work was to asses whether the association described in Asian populations is replicated in Europeans. METHODS: This study includes a total of 1155 Spanish subjects of European origin (372 BD and 783 unrelated healthy individuals). Patients were recruited from different hospitals and controls were collected in the same geographic regions and they matched with patients in age and gender. A total of five SNPs, two in the JAK1 gene: rs2780815 and rs310241 and the other three in the TNFAIP3: rs10499194, rs9494885 and rs610604, were included in this study. The genotyping of these SNPs was performed using a real time PCR system (TaqMan® SNP Genotyping Assays). RESULTS: No statistically significant differences were found when the patient and control groups were compared. The distribution of the risk alleles was similar in patients with and without eye manifestations and in patients with and without HLA-B*51. CONCLUSIONS: The association of variants of the genes JAK1 and the TNFAIP3 with BD which has been described in the Chinese population was not replicated in Europeans.

Activation of the JAK/STAT pathway in Behcet's disease.

Th1/Th17-type T-cell responses are upregulated in Behcet's disease (BD). However, signaling pathways associated with this aberrant immune response are not clarified. Whole-genome microarray profiling was performed with human U133 (Plus 2.0) chips using messenger RNA of isolated CD14(+) monocytes and CD4(+) T cells from peripheral blood mononucleated cell (PBMC) in patients with BD (n = 9) and healthy controls (HCs) (n = 9). Flow cytometric analysis of unstimulated (US) and stimulated (phytohaemagglutinin) signal transducer and activator of transcription (STAT3) and pSTAT3 expressions of PBMCs were also analyzed (BD and HC, both n = 26). Janus family of kinase (JAK1) was observed to be upregulated in both CD14(+) monocytes (1.95-fold) and CD4(+) T lymphocytes (1.40-fold) of BD patients. Using canonical pathway enrichment analysis, JAK/STAT signaling was identified as activated in both CD14(+) monocytes (P = 9.55E-03) and in CD4(+) lymphocytes (P =8.13E-04) in BD. Interferon signaling was also prominent among upregulated genes in CD14(+) monocytes (P = 5.62E-05). Glucocorticoid receptor signaling and interleukin (IL-6) signaling were among the most enriched pathways in differentially expressed genes in CD14+ monocytes (P = 2.45E-09 and 1.00E-06, respectively). Basal US total STAT3 expression was significantly higher in BD (1.2 vs 3.45, P < 0.05). The JAK1/STAT3 signaling pathway is activated in BD, possibly through the activation of Th1/Th17-type cytokines such as IL-2, interferon (IFN-γ), IL-6, IL-17 and IL-23.

Purification of paraoxonase enzyme from the sera of patients with Behcet's disease and analyzing the effects of the drugs containing imuran (azathioprine), prednisolone (methylprednisolone) and colchium (colchicine).

In this study, serum samples from 50 patients with the diagnosis of Behcet's disease and 20 healthy volunteers were analyzed. The study consists of three parts. In the first part, paraoxonase (PON) activities were determined in the serum samples of 50 patients with Behcet's disease and 20 healthy people. In the second part, equal volumes of serum samples from 50 patients were pooled and PON enzymes were purified by using Sepharose-4B-L-tyrosine tyrosine-1-naphtylamine affinity column. Optimum temperature, optimum pH, Vmax and Km values of the pure enzymes were determined. The same purification procedure was also performed in the serum samples of 20 healthy people. Electrophoretic mobility was observed (via SDS-PAGE) in the PON enzymes that were purified from the serum samples of patients with Behcet's disease and healthy people. In the third part, in vitro effects of drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of Behcet's disease were tested on the PON enzymes of the patients with Behcet's disease and control group. IC50 values and Ki constant values were measured and inhibition types were determined for the drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of the Behcet's disease and demonstrate in vitro inhibition effects.

Mevalonate kinase gene mutations and their clinical correlations in Behçet's disease.

AIM: Genetics is suggested to play a role in the development of Behçet's disease (BD). Shared phenotipic features requires an approach to differential diagnosis from periodic febrile syndromes. We planned to study for mevalonate kinase (MVK) as a candidate for a susceptibility gene for Behçet's disease. METHOD: Consecutive Behçet patients and apperently healthy subjects were included. Severity score of Behçet disease was calculated. Genotyping of mevalonate kinase gene was performed by polymerase chain reaction/sequence-based typing technique. RESULTS: Fifty BD patients (median age: 38.30 ± 11.06 years) and 51 controls (median age: 33.88 ± 12.47 years) were recruited. Three types of mutations have been found: first, a single nucleotide polymorphism (SNP) c.769-38C>T (rs35191208) in 21 of 50 BD patients and in 15 of 51 controls. Both groups were comparable for the frequency of c.769-38C>T (P > 0.05). In all of the cases with c.769-38C>T, a second SNP, c885+24G>A (rs2270374) was also present (previously reported to be in linkage disequilibrium with the first SNP). A third SNP, c.769-7T>G (rs104895331) was found in three of 50 BD patients and in one of the control group. We found this SNP together with c769-38C>T and c.885+24G>A. The neurological involvement was found to be more frequent in the BD patients with c.769-3C>T when compared to the BD patients without this polymorphism (P = 0.012). CONCLUSION: Our results suggested that the effects of MVK mutations in Behçet's disease could be an additional genetic susceptibility factor for the patients with neurological involvement. However, these results need confirmation in larger study populations and in different ethnic groups.

Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and variations of homocysteine concentrations in patients with Behcet's disease.

BACKGROUND: Behcet's disease (BD) is a chronic, relapsing, multi-systemic inflammatory disorder of unknown causes. This disease is mainly characterized by mucocutaneous, ocular, vascular, and central nervous system manifestations. The aim of this study is to investigate the associations between C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the plasma homocysteine (Hcy), folate, and B12 levels in a relatively large cohort of Tunisian patients with BD. METHODS: The study included 142 patients with BD and 172 healthy controls. The C677T and A1298C polymorphisms were genotyped using PCR-RFLP. Serum Hcy level was determined using a fluorescence polarization immunoassay. Serum folate and vitamin B12 levels were measured by electrochemiluminescence immunoassay. RESULTS: Genotype and allele frequencies of the two studied MTHFR polymorphisms did not show any significant differences among BD patients compared to controls. Patient carriers of the 677TT variant and the 677T allele displayed significantly higher Hcy concentration. Moreover, no significant association was found between neither A1298C polymorphism nor the C allele and Hcy, folate, and B12 levels. In multivariate analyses, we reported that 677T allele, male gender, and creatinine level were independent risk factors for hyperhomocysteinemia (HHC). CONCLUSIONS: In the present study, we report the absence of any significant differences between genotype and allele frequencies for both studied polymorphisms among BD patients compared to healthy controls. Besides, we showed that the T allele of MTHFR C677T polymorphism influenced the Hcy level which is an independent risk factor for HHC in Tunisian BD patients.

Lipoprotein-associated phospholipase A2 level in patients with Behçet's disease.

BACKGROUND: Behçet's disease (BD) is a chronic multisystem inflammatory disorder characterized by vasculitis. Vasculitis is thought to underlie many of the clinical manifestations of Behçet's disease. Lipoprotein-associated phospholipase A2 (Lp-PLA2 ) is a highly specific biomarker for vascular inflammation, and has low biological variability. Those features make it more attractive than other inflammatory markers including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), which may reflect systemic inflammation non-specifically. OBJECTIVES: It was aimed to investigate circulating Lp-PLA2 levels and its relationship with CRP and ESR in patients with BD by considering disease activity. METHODS: Study group included 72 patients with BD (34 men and 38 women with a mean age of 35.3 years) and 30 sex- and age-matched healthy subjects (15 men and 15 women with a mean age 32.6 years). Patients group included 40 patients with active and 32 patients with inactive BD. RESULTS: Lp-PLA2 , CRP and ESR levels were found to be significantly higher in patient group than controls. In addition, those levels were also significantly higher in patients with active BD than in patients with inactive disease. Lp-PLA2 showed positive correlations with CRP and ESR (r = 0.63, P < 0.05 and r = 0.33, P < 0.05 respectively). Lp-PLA2 also showed significant important area under curve (AUC) value (0.779), besides CRP (0.941) and ESR (0.888). Optimum cut-off value was obtained as 218.5 ng/mL. CONCLUSIONS: It was concluded that Lp-PLA2 may be a new useful biomarker to evaluate clinical or subclinical activity of the disease besides CRP and ESR.

Association between Rho-kinase (ROCK2) gene polymorphisms and Behçet's disease.

Behçet's disease (BD) is a multi-systemic vasculitis. The aim of this study was to investigate the association between Rho-kinase (ROCK2) gene polymorphisms and patients with BD in a Turkish population. A total of 194 BD patients and 276 healthy controls with similar age and sex were included to this study. Polymorphisms were analyzed in genomic DNA using a BioMark 96.96 dynamic array system. mRNA from blood samples was extracted, and real-time polymerase chain reaction was performed for ROCK2 gene expression. There were marked changes in both genotype (TT, 41.8%; TA, 30.3%) and allele (T, 57%; A, 43%) frequencies for the rs35768389 (Asp601Val) polymorphism in patients compared with controls (TT, 64.6%; TA, 9.4%, P < 0.0001; T, 69.3%; A, 30.7%, P = 0.0004). Although CC genotype (52.0%) of rs1515219 polymorphism were more frequent, CT genotype (27.7%) were less frequent among the patients than controls (CC, 31.7%, CT, 44.6%, P = 0.0001). There was an increase in C allele (65.8% vs 54.0%) and decrease in T allele frequencies (34.2% vs 46.0%, P = 0.001) in patients. However, no associations were found with rs726843, rs2290156, rs965665, rs10178332, rs2230774, rs6755196, rs10929732, and rs34945852 polymorphisms. There was an increase in peripheral blood mRNA ROCK2 expressions in patients. This is the first study to examine the involvement of ROCK2 gene variation in the risk of incident BD. The results strongly suggest that ROCK2 gene polymorphisms may modify individual susceptibility to BD in the Turkish population.

The impact of smoking on clinical features of Behçet's disease patients with glutathione S-transferase polymorphisms.

OBJECTIVES: Various cancer studies have suggested that polymorphism of GSTM1 may influence the ability to detoxify chemicals in cigarette smoke. In the present study the effect of smoking on clinical features of Behçet's disease were investigated in patients having GST-M1 and/or -T1 null polymorphisms. METHODS: Ninety-seven patients meeting International Study Group Criteria for Behçet's disease (63 male, 34 female) and 172 healthy controls (94 male, 78 female) were included into the study. GST-M1 and -T1 polymorphisms were investigated using polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: Frequency of GSTM1- and/or GSTT1-null polymorphisms were comparable between the Behçet and the control groups. Smoking patients with GSTM1 null-polymorphism have decreased risk of developing papulopustuler lesions (OR=0.227 [0.063-0.818], χ2=5.463, p=0.019). Non-smoking patients with GSTM1 null-polymorphism has increased risk for having chronic arthritis (OR=5.988 [0.845-43.478]) but smoking patients with GSTM1 null-polymorphism have decreased risk (OR=0.741 [0.593-0.926]). GSTT1 null-polymorphism is associated with the presence of venous insufficiency (χ2=6.273, p=0.012, OR=2.740 [1.224-6.135]); smoking further increases the risk (χ2=7.840, OR=3.333 [1.412-7.874], p=0.005). GSTM1 null-polymorphism seemed to effect development of large vessel vasculitis (OR=1.158 [0.981-1.367], χ2=4.760, p=0.029). Male smoker Behçet patients even have more risk (OR=1.250 [0.971-1.610]). CONCLUSIONS: Several manifestations of Behçet's disease may be influenced by smoking, and this effect can be augmented in patients carrying GST gene polymorphism, which code enzymes crucial for the detoxification of chemicals.

Replication study confirms the association between UBAC2 and Behçet's disease in two independent Chinese sets of patients and controls.

INTRODUCTION: The purpose of this study was to replicate genetic factors associated with the susceptibility to Behçet's disease (BD). We conducted a two-stage candidate genes association and functional study, involving 477 BD patients and 1,334 normal controls of Chinese Han descent. METHODS: The genotyping of five candidate genes/loci, including LOC100129342, KIAA1529, CPVL, UBASH3B and UBAC2, were performed using TaqMan single nucleotide polymorphism (SNP) assays. Real-time PCR and luciferase reporter assay were performed to test the function of the identified promoter polymorphism. The main outcome measures were genotype frequencies and expression levels in BD patients. RESULTS: The first-stage study results showed that UBAC2 (rs9513584, Pc = 0.018, OR = 1.4), but not LOC100129342, KIAA1529, CPVL, UBASH3B was associated with the susceptibility to BD in Chinese Han. The fine-mapping association study of UBAC2 identified six risk SNPs for BD in the Chinese cohort; three of them were verified in validation study (rs3825427, first-stage Pc = 2.2 × 10-3, second-stage Pc = 9.3 × 10-3, combined Pc = 6.9 × 10-6; rs9517668, first-stage Pc = 1.7 × 10-3, second-stage Pc = 0.03, combined Pc = 3.3 × 10-4; rs9517701, first-stage Pc = 5.1 × 10-3, second-stage Pc = 9.0 × 10-3, combined Pc = 2.9 × 10-5; respectively). Functional analysis showed that the risk T allele of the promoter polymorphism rs3825427 had a significantly lower promoter activity than the non-risk G allele (P = 0.002) and a decreased expression of UBAC2 transcript variant 1 in peripheral blood mononuclear cells (PBMCs) and skin of normal controls carrying the risk T allele than that in individuals with the G allele (P = 0.045, P = 0.025; respectively). The mRNA expression of UBAC2 transcript variant 1 was significantly decreased in PBMCs and skin of BD patients as compared with controls (P = 0.025; P = 0.047, respectively). The mRNA expression of UBAC2 transcript variant 2 was significantly increased in skin of BD patients as compared with controls (P = 0.004). CONCLUSIONS: This study replicates a predisposition gene to BD, UBAC2, and suggests that UBAC2 may be involved in the development of BD through its transcriptional modulation.

Associations between eNOS polymorphisms and susceptibility to Behcet's disease: a meta-analysis.

OBJECTIVE: To determine whether endothelial nitric oxide synthase (eNOS) polymorphisms confer susceptibility to Behcet's disease (BD). METHODS: A meta-analysis was conducted on the associations between the G894T and 4b/a polymorphisms of eNOS and BD using: (i) the allele contrast, (ii) the recessive model, (iii) the dominant model and (iv) the additive model. RESULTS: A total of eight studies, which included 841 cases and 866 controls, were included in the meta-analysis. Meta-analysis of the G894T polymorphism revealed no association with BD in all study subjects or in Turkish and Asian populations. However, one Tunisian study of the T allele showed a significant association with BD (OR = 0.707, 95% CI = 0.510-0.980, P = 0.038), but the OR of the T allele among Tunisians was lower, whereas it was higher in Europeans (OR = 2.129, 95% CI = 1.407-3.220, P = 0.0003). Meta-analysis showed no association between BD and the 4b/a polymorphism in all study subjects. Stratification by ethnicity indicated no significant association between the a allele of the 4b/a polymorphism and BD in Turkish and Asian populations. CONCLUSIONS: This meta-analysis shows that the eNOS G894T and the 4b/a polymorphisms are not associated with BD in the Turkish and Asian populations. These data suggest that the G894T and the 4b/a polymorphisms may not confer susceptibility to BD in the Turkish and Asian populations.