IL-1 cluster gene polymorphisms in Turkish patients with Behçet's disease

Several cytokine genes may play crucial roles in host susceptibility to Behçet’s Disease (BD), since the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphisms. The association of the IL‐1 cluster gene polymorphisms with the development of BD was investigated in this study. DNA samples were obtained from a Turkish population of 97 patients with BD, and 77 healthy control subjects. All genotyping (IL‐1α, IL‐1β, IL‐1R and IL‐1Ra) experiments were performed using sequence specific primers PCR (PCR‐SSP). When compared to the healthy controls, the frequencies of IL‐1Ra IL‐1α and IL‐1R gene polymorphisms were not significantly different in BD patients. The frequency of IL‐1β?511 TT genotype was higher in the BD group in comparison to the control group. Interestingly, we demonstrated that IL‐1 β +3962 gene polymorphism seems to be associated with the presence of Erythema nodosum in BD patients. Our data suggest that polymorphisms in IL‐1β gene may affect host susceptibility to BD. In order to confirm the biological significance of our results, further studies should be performed in a large‐scale study and/or in different ethnic groups.     

Interleukin-18 promoter polymorphisms in patients with Behçet's disease

Beh?et's disease (BD) is an idiopathic systemic inflammatory disease and is considered to be a T helper 1 (Th1) type cytokine driven disorder. Moreover, levels of interleukin-18 (IL-18), a pivotal mediator of Th1 cytokine response, have been reported to be upregulated in BD. Therefore, we investigated the distribution of IL-18 promoter -607 C/A and -137 G/C polymorphisms in 103 BD patients (mean age 41.0 years; 48 male, 55 female) using allele-specific-polymerase chain reaction. As compared with healthy control subjects, BD patients had a significantly higher frequency of the -607 CC genotype (42.7% vs 23.3%, odds ratio [OR] = 2.455, 95% confidence interval [CI] = 1.350-4.461, p(c) = 0.021) and a higher frequency of the -607 C allele (60.7% vs 48.1%, OR = 1.668, 95% CI = 1.129-2.464, p = 0.0101). Haplotype analysis showed that BD patients had significantly less -607A/-137G haplotype (27.3% vs 44.2%, OR = 0.469, 95% CI = 0.268-0.820, p(c) = 0.032) and -607A/-137G haplotype homozygote (5.8% vs 20.4%, OR = 0.242, 95% CI = 0.096-0.612, p(c) = 0.014) than control subjects. In addition, the frequency of -607C/-137G haplotype homozygote was significantly higher in BD patients than control subjects (48.5% vs 20.4%, OR = 3.684, 95% CI = 1.997-6.791, p(c) = 0.0014). Although there were no associations between the polymorphisms and clinical manifestations or severity, patients with the -607 CC genotype or -607C/-137G haplotype homozygote showed significantly earlier symptom development (p = 0.034 by ANOVA; p = 0.009 by t-test, respectively) than those with other genotypes or diplotypes. These results suggest that the IL-18 promoter gene is a candidate susceptibility gene in BD patients.     

Association analysis of Toll-like receptor 7 gene polymorphisms and Behçet's disease in Japanese patients

Action of Toll-like receptors (TLRs) is deeply associated with defense mechanisms of the innate and adaptive immune responses to microbial pathogens. There have been reports of genetic polymorphisms within the TLR7 gene being closely related to a variety of inflammatory and infectious diseases. Behçet's disease (BD) is an autoinflammatory disease, and the pathogenesis has yet to be fully discovered. We investigated whether polymorphisms of Toll-like receptor 7 (TLR7) are associated with BD by analyzing the frequency of eight single nucleotide polymorphisms (SNPs) within 200 Japanese BD patients and 102 randomized controls. We genotyped nine SNPs in the TLR7 gene and assessed the allele/genotype diversity between cases and controls for all SNPs. In all eight SNPs, statistically significant differences were not observed between cases and controls.     

Lack of association of Toll-like receptor 9 gene polymorphism with Behçet's disease in Japanese patients

Toll-like receptors (TLRs) play an important role in the induction of defense mechanisms of the innate and adaptive immune responses to microbial pathogens. Genetic polymorphisms within the TLR9 gene have been reported to be associated with a variety of inflammatory and infectious diseases. Beh?et's disease (BD) is a chronic inflammatory disease, and the etiology of BD has yet to be fully elucidated. We investigated the potential association of the TLR9 gene with susceptibility to BD by analyzing the frequency of nine single nucleotide polymorphisms (SNPs) in a population of 200 Japanese BD patients and 102 randomized controls. Our results showed that SNPs in the TLR9 gene were not significantly associated with susceptibility to BD.     

Class I and class II MHC polymorphisms in Mexican patients with Behçet's disease

Beh?et's disease is a multi-system inflammatory disorder of unknown etiology. The disease is more prevalent in Eastern Mediterranean countries and Japan where there is a linkage to HLA-B51. Mexican Mestizos are suitable subjects for studying the role of ethnicity in the susceptibility to Beh?et's disease. High-resolution HLA class I and class II typing was performed by polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) reverse dot blot and PCR-single-strand polymorphism in 32 patients with Beh?et's disease and 99 healthy ethnically-matched controls. A significant increased frequency of HLA-B(*)44 (P = 0.02; OR = 2.78; CI 95% = 1.1-7.7), HLA-B(*)52 (P = 0.02; OR = 5.33; CI 95% = 1.07-29.1), and HLA-B(*)56 (P = 0.003; OR = 4.19; CI 95% = 3.37-5.21) as well as HLA-DRB1(*)01 and HLA-DRB1(*)13 (p = 0.007; OR = 3.36; CI 95% = 1.22-9.27) was found in Mexican patients with Beh?et's disease when compared to controls. The low frequency of native markers in Mexican Mestizo patients with Beh?et's disease suggests that genetic admixture between Eastern Mediterraneans and Orientals with Amerindians is a recent event that increased the risk of developing Beh?et's disease in the Mexican population.     

Interleukin-4 gene polymorphisms confer Behçet's disease in Turkish population

Several cytokine genes may play crucial roles in host susceptibility to Behçet’s Disease (BD), because the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphisms. The association of the IL‐4 and IL‐4Rα gene polymorphisms with the susceptibility to BD was investigated in this study. DNA samples were obtained from a Turkish population of 97 patients with BD and 76 healthy control subjects. All genotyping (IL‐4 and IL‐4Rα) experiments were performed using PCR sequence‐specific primers. When compared with the healthy controls, the frequency of IL‐4 ?1098 TG and ?590 CT genotypes was higher in the patients with BD. Analysis of allele frequencies showed that IL‐4 ?1098 G and IL‐4 ?590 T alleles were more common in the patients with BD when compared with healthy controls. Also, IL‐4 TTC and haplotypes were found to confer BD. Interestingly, we demonstrated that IL‐4Rα gene polymorphism seems to be associated with the Pathergy test positivity in patients with BD. Our data suggest that IL‐4 gene promoter polymorphisms may affect susceptibility to BD and increase risk of developing the disease. However, in order to confirm and assess the association of IL‐4 and IL‐4Rα gene polymorphisms with the BD, large cohort studies are needed.     

Influence of sex on patients with Behçet's disease in Korea

Behçet''s disease (BD) is a multisystemic inflammatory disorder known as having a histopathological findings of vasculitis. The influence of sexual difference on BD is a well-known fact and there are several reports suggesting a more severe course of the disease among young males. The purpose of our study was to determine the effects of gender on the severity and clinical features of BD patients in Korea. The study included 1,901 patients with BD who fulfilled the criteria of International Study Group for Behçet''s Disease or corresponded to the complete or incomplete type for the revised criteria of Behçet''s Disease Research Committee of Japan. BD in Korea showed a female predominance (M:F=0.61:1). The skin lesions were observed in 79.9% of patients, of which 77.6% had erythema nodosum-like lesion, which was more frequent in females. The ocular lesions were more common in males showing a higher frequency of uveitis. Ocular and vascular symptoms as clinical features with severe complications or mortality were more frequent in males than in females. The mean age at the onset of patients with the worst prognosis such as ocular, gastrointestinal, neurologic, and vascular involvements was significantly younger in male than in female patients (p<0.05). In conclusion, this study elucidated the influences of sexual difference on BD in Korea.     

IL-10 genotype analysis in patients with Behçet's disease

Beh?et's disease (BD) is a multisystem inflammatory disease characterized by recurrent orogenital ulceration, ocular inflammation, and skin lesions. The etiology of the disease is currently unknown but evidence suggests that there is a strong genetic component mediating the chronicity of the disorder. We have examined the association between polymorphisms at position -1082, and -819 in the promoter region of the gene encoding IL-10 in patients with Beh?et's disease from two distinct patient populations. The IL-10 -1082AA genotype was weakly associated with BD when all patients were analyzed as a group (pc = 0.04, OR 1.4, 95% CI 1.1-1.9), but not in the UK or Middle Eastern (ME) cohorts of patients alone compared to local controls. An association with IL-10 -819T was evident in all BD patients, (pc = 0.02, OR 1.5, 95% CI 1.1-2.0), and this was because of an association in the UK but not ME patients (pc = 0.0004, OR 2.1, 95% CI 1.4-3.3). The -1082A/-819T haplotype, which is linked to low production of this cytokine, was not significantly associated with Beh?et's disease. This link between BD, a chronic, relapsing, autoinflammatory condition, and a genotype associated with low IL-10 production provides evidence that abnormalities in the genetic control of cytokine levels may be relevant in influencing the immune response in Beh?et's disease in some patient groups.     

Levels of IL-15 in serum and cerebrospinal fluid of patients with Behçet's disease

Interleukin‐15 (IL‐15) is a novel proinflammatory cytokine, involved in the pathogenesis of inflammatory/autoimmune disease. The objective of our study was to measure serum and cerebrospinal fluid (CSF) IL‐15 levels in patients with Behçet's disease (BD). CSF/serum IL‐15 ratio was introduced to assess the origin of elevated IL‐15 levels. We measured serum and CSF‐IL‐15 levels in 40 patients with BD (20 patients in active stage). Inflammatory and non‐inflammatory neurological disease patients acted as controls. Active BD patients have significantly higher serum IL‐15 levels (median 10.4 pg/ml; range 5.3–17.4) compared with BD in remission (6.05 pg/ml; 4–10.4) and healthy controls (4.65 pg/ml; 3.9–6.2). Similar serum IL‐15 levels were found in active neuro‐BD and inflammatory neurological disease (9.5 pg/ml; 5–13). Elevated levels of IL‐15 were observed in CSF samples from neuro‐BD patients (11 pg/ml; 8.5–15) and inflammatory neurological disease patients (10 pg/ml; 6.5–14) compared with patients with non‐inflammatory neurological disease (4 pg/ml; 4–5.5; P < 0.001). Vascular cerebral BD lesions were associated with high CSF/serum IL‐15 ratio. Our findings suggest that IL‐15 is involved in BD inflammatory process, particularly in vasculitis foci, as an elevated CSF/serum IL‐15 ratio characterizes vascular cerebral lesions.     

PTPN22 gene polymorphism in Behçet's disease

A functional single nucleotide polymorphism (SNP) of PTPN22 gene encoding the protein tyrosine phosphatase has been reported to be associated with autoimmune disorders such as rheumatoid arthritis, systemic lupus erythematosus and type I diabetes. PTPN22 R620W polymorphism has a wide variation of allelic frequencies among different populations. This polymorphism is investigated in Turkish patients with Beh?et's disease (BD), a systemic vasculitis with immune activation. DNA samples from 134 patients with BD and 177 healthy controls are genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism method for the SNP (rs2476601, A/G) of PTPN22 gene. Polymorphic region was amplified by PCR and digested with XcmI enzyme. The frequency of heterozygous genotype (AG) was 5.1% (9/177) in control group, whereas polymorphic allele was not present in the whole BD group (P = 0.012, OR 0.65, 95% confidence interval 0.0-1.1). Both the lower prevalence in the general population and the absence in BD show the limited role of PTPN22 polymorphism in the pathogenesis of autoimmunity in Turkey.     

Alpha tropomyosin as a self-antigen in patients with Behçet's disease

We report for the first time a significant increased lymphoproliferative response to alpha tropomyosin as well as observing autoantibodies to tropomyosin observed in Behcet's disease (BD) patients with posterior uveitis. Peripheral blood mononuclear cells (PBMCs) from 18 BD patients with posterior uveitis, 18 patients with other forms of noninfectious uveitis, 9 patients with retinal damage due to photocoagulation as well as 18 healthy donors were evaluated for antigen-specific lymphoproliferative responses to alpha tropomyosin and its derivative peptides. The proliferative responses of PBMCs to these antigens were studied using (3)H thymidine incorporation assay. Serum samples were also screened by ELISA for autoantibodies against tropomyosin. Six of the 18 (33%) BD patients with posterior uveitis showed increased proliferative response to alpha tropomyosin or its derivative peptides, while none of the healthy, disease controls were positive. The mean lymphoproliferative responses to tropomyosin were significantly higher (P < 0.02) in the BD patients compared to healthy or disease controls. Higher titres of anti-tropomyosin antibodies were also seen in four of the 18 BD patients but none in the healthy or disease control groups (P < 0.002). The occurrence of these abnormalities supports a possible role for alpha tropomyosin as a self-antigen in a subset of patients with Behcet's disease.     

Intima-media thickness and arterial stiffness of carotid artery in Korean patients with Behçet's disease

Behçet''s disease (BD) is a systemic vasculitis involving diverse sizes of arteries and veins. We performed this study to evaluate the vascular changes by assessment of the arterial stiffness and intima-media thickness (IMT) of carotid artery in Korean patients with BD. Forty-one patients with BD and age-, and sex-matched 53 healthy subjects were recruited in this study. Carotid arterial stiffness and IMT were assessed by using high-resolution B-mode ultrasonography. Arterial stiffness parameters such as carotid arterial distensibility coefficient, stiffness index, and incremental elastic modulus (E_inc) were significantly increased in BD patients compared with those in healthy subjects, but not in IMT. Positive relationship was noted between age and IMT, whereas age of onset was significantly associated with arterial stiffness in BD. This finding suggests impaired endothelial function before visible structural changes of arterial wall in BD. Age and age of onset may be an independent risk factor for carotid IMT and arterial stiffness, respectively. Further studies in more large populations are required to confirm our results.     

Serum oxidant/antioxidant status in patients with Behçet's disease

The aims of this study were to assess whether the increased oxidative stress in affected tissues is reflected by serum lipid peroxidation and to check for alterations in serum levels of extracellular antioxidants and antioxidant enzyme activities in patients with Behcet's disease (BD). Serum malondialdehyde (MDA) and ceruloplasmin (Cp) levels and CuZn-superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) activities were increased, while serum transferrin (Trf) levels were diminished in patients with active ocular BD (n = 19), inactive ocular BD (n=18), and nonocular BD (n=15), compared to healthy controls (n = 20). Serum MDA levels in patients with active ocular BD and nonocular BD were significantly higher than in the inactive ocular BD group. Patients with active ocular BD also had significantly higher serum Cu-Zn SOD activities, compared to the inactive ocular BD. Erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) levels were higher in patients with active ocular BD, inactive ocular BD, and nonocular BD, compared to the control group. In addition, patients with active ocular BD and nonocular BD had significantly higher ESR and serum CRP levels, compared to the inactive ocular BD group. Serum albumin concentrations showed no significant differences among the BD patients and controls. The authors speculate that in BD patients, serum superoxide radicals may be dismutated to H2O2 by increased CuZn-SOD activity and the conversion of H2O2 to hydroxyl radical may be enhanced by iron, owing to diminished serum Trf; these mechanisms may contribute to the increased serum lipid peroxidation.     

Aberrant Fas ligand expression in lymphocytes in patients with Behçet's disease

BACKGROUND: Defects in immune responses have been reported in patients with Beh?et's disease (BD). To further characterize the immune dysfunction and its contribution to the pathogenesis, we have studied Fas ligand (FasL) expression in peripheral blood lymphocytes (PBL) and mononuclear cells in the skin lesions in patients with BD. METHODS: FasL expression in PBL was studied with RT-PCR and immunoblotting with rabbit anti-human FasL antibody. We studied the expression of FasL in cryostat sections of biopsy specimens of erythema nodosum lesions from 4 patients with BD and of a genital ulcer lesion in another patient using immunohistochemical staining. Apoptotic cell death was detected with the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method. RESULTS: We found that FasL mRNA and FasL protein expression was detected marginally in the unstimulated PBL, and was induced upon activation in normal individuals. PBL from patients with BD exhibited an enhanced expression of FasL mRNA and FasL protein without in vitro stimulation. Moreover, mitogen stimulation failed to augment FasL expression of their lymphocytes, suggesting a dysregulation of FasL expression of PBL in patients with BD. The skin biopsy specimens revealed that cells infiltrating into skin lesions expressed FasL and there were several TUNEL staining-positive cells in the lesions, suggesting that Fas/FasL-mediated apoptosis is involved in the development of the skin lesion and thus may be associated with the pathogenesis. CONCLUSIONS: We found an excessive expression of FasL in circulating as well as skin-infiltrating lymphocytes and the presence of apoptotic cells in the skin lesions, suggesting that lymphocytes expressing FasL aberrantly may play a role in the development and pathogenesis of BD.     

Allelic diversity and affinity variants of MICA are imbalanced in Spanish patients with Behçet's disease

The aetiology of Behçet's disease (BD) is still unknown, but genetic and environmental factors are involved. HLA‐B*51 is considered a susceptibility marker and some MICA alleles have also been associated. Cytotoxic T lymphocytes have been suggested as responsible for BD lesions by engaging MICA through NKG2D surface molecules. In the present study, HLA‐B and MICA alleles were typed by polymerase chain reaction using sequence‐specific primers, in 165 healthy Spanish controls and 42 BD patients. In the healthy group, MICA*008 (28.48%), MICA*004 (17.58%), MICA*002 (14.24%) and MICA*009 (9.39%) were the predominant alleles and the most common haplotype was MICA*004‐B*44 (12.12%). MICA*001 (5.15%), MICA*004, MICA*011 (4.54%) and MICA*018 (5.15%) were more frequent, and MICA*010 (1.81%) and MICA*008 were less prevalent than in other Caucasoid populations. Similar results have been reported in North African individuals and this could support the hypothesis of a common ancestral origin of both populations. The frequencies of MICA*009 and MICA*019 were significantly increased in our BD patients in comparison with controls: 22.62% versus 9.39% and 10.71% versus 1.81% respectively. The increase of MICA*019 had not been described in other BD cohorts, and it corroborates the genetic heterogeneity at MICA locus in BD patients. High‐affinity MICA alleles for NKG2D were more frequent in controls than in patients. Moreover, high‐affinity alleles were not found in homozygous BD patients. These results argue against the hypothesis of an autoaggressive response in BD patients through MICA–NKG2D interactions.     

Sleep disorders in Behçet's disease, and their relationship with fatigue and quality of life

Behçet’s disease, a systemic vasculitis, can cause varying degrees of activity limitation, fatigue and quality of life impairment. To date, there have been no studies regarding sleep disturbance and its relationship with fatigue and life quality in Behçet’s disease. We aimed to evaluate sleep disorders and polysomnographic parameters, and to determine their relationship with fatigue and quality of life in Behçet’s disease. Fifty‐one patients with Behçet’s disease without any neurological involvement were interviewed regarding sleep disorders. Twenty‐one subjects with no sleep complaints were included as the control group. Sleep‐related complaints were evaluated in a face‐to‐face interview. Sleep quality, excessive daytime sleepiness, fatigue, depression, anxiety, disease activity/severity, and quality of life questionnaires and an overnight polysomnography were performed. Prevalences of restless legs syndrome (35.3%) and obstructive sleep apnea syndrome with/without other sleep disorders (32.5%) were higher than in the control group and the general population. Fatigue was higher in patients with restless legs syndrome and obstructive sleep apnea syndrome, and in those with lower minimum oxygen saturation; hence, only patients with restless legs syndrome had quality of life impairment. Sleep efficiency index and sleep continuity index were lower, and wake after sleep onset, respiratory disturbance index and apnea–hypopnea index were higher than in controls (P < 0.01). Neither sleep disorders nor polysomnographic parameters were related to disease activity and severity. In conclusion, it is important to question sleep disorder followed by a polysomnography, if necessary, in order to improve quality of life and fatigue in Behçet’s disease.     

Factor V gene (1691A and 4070G) and prothrombin gene 20210A mutations in patients with Behçet's disease

OBJECTIVES: Beh?et's disease (BD) is a chronic inflammatory disorder of still unknown etiology, characterized by endothelial cell injury/dysfunction and thrombosis and/or aneurysm of large blood vessels. Thrombophilia may play a role in the pathogenesis of thrombosis in BD. The common inherited gene defects, factor V (FV) 1691A (Leiden) and prothrombin (PT) 20210A, are known risk factors for thrombosis. The FV 4070G polymorphism was shown to influence circulating FV levels and to contribute to the activated protein C resistance phenotype. The aim of the study was to evaluate the role of FV 1691A, FV 4070G and PT 20210A gene mutations in Turkish BD patients with and without venous thrombosis. METHODS: Seventy-one patients with BD (27 with venous thrombosis) and 91 healthy subjects were included in the study. FV 1691A, FV 4070G, and PT 20210A mutations were determined by a method based on PCR-RFLP. RESULTS: The frequency of FV 1691A heterozygous mutation in BD patients with venous thrombosis (25.9%) was significantly higher than that in healthy subjects (8.8%; OR = 3.63; 95% CI 1.18-11.2). Although the frequency of this mutation in patients with venous thrombosis was higher than that in the patients without venous thrombosis (11.4%), the difference did not reach a statistically significant level (OR = 2.73; 95% CI 0.77-9.70). In BD patients with thrombosis, the frequencies of FV 4070G and PT 20210A were not significantly different compared to the BD patients without venous thrombosis and healthy subjects. CONCLUSIONS: Our results suggest that the FV 1691A, FV 4070G, and PT 20210A mutations are unlikely to play an important role in the pathogenesis of thrombosis in patients with BD.     

Behçet's disease combined with various types of fistula

Behçet''s disease (BD) is a chronic, relapsing, multisystem disorder, characterized by recurrent oral ulcer, genital ulcers, eye lesion, and skin lesion. The underlying pathology is nonspecificvasculitis of all vessel sizes, and severe vasculitis can result in fistula formation of neighboring tissues due to a necroticprocess. Herein, eleven cases of BD combined with fistula are presented. In the present study, various types of fistula were associated; enterocutaneous fistula in six patients, and rectovaginal fistula in two. The other three patients showed aortoduodenal fistula, urethrovaginal fistula and urethrocutaneous fistula. They were treated with a corrective operation, but the prognoses were poor due to frequent relapses.     

Analysis of microsatellite polymorphism around the HLA-B locus in Iranian patients with Behçet's disease

We have previously suggested that in a Japanese population the susceptible locus for Beh?et's disease (BD) is HLA-B51 itself. To confirm this finding in another population, we performed HLA class I typing using the PCR-SSP method and analyzed eight polymorphic markers distributed within 1100 kb around the HLA-B gene using automated sequencer and subsequent automated fragment detection by fluorescent-based technology with the DNA samples of 84 Iranian patients with BD and 87 healthy ethnically matched controls. As a result, three microsatellite alleles (MICA-A6, MIB-348, C1-4-1-217) and HLA-B51 were found to be strongly associated with BD. Of these alleles HLA-B51 is the most strongly associated allele. There were no alleles that were increased in allele frequency at any microsatellite loci centromeric of MICA or telomeric of HLA-B51. Therefore, HLA-B51 was confirmed to be by far the most strongly associated gene with BD in an Iranian population.