Significant associations of HLA-B*5101 and B*5108, and lack of association of class II alleles with Behçet's disease in Italian patients

Beh?et's disease has been known to be strongly associated with human leukocyte antigen (HLA) B51, one of the split antigens of HLA-B5. An increased incidence of HLA-B51 in the patient group has also been reported in an Italian population. Since the B51 antigen has been recently identified to comprise nine alleles, B*5101-B*5109, we performed HLA-B51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method as well as serological HLA-A and -B typing among 21 Italian patients with Beh?et's disease in order to investigate whether there is any correlation of one particular B51-associated allele with Behcet's disease. In addition, HLA class II genotyping was performed by the PCR-restriction fragment length polymorphism (RFLP) method. As a result, only the phenotype frequency of the B51 antigen was found to be significantly increased in the patient group as compared to the ethnically matched control group by the corrected P-value analysis (71.4% in patients vs. 17.9% in controls; chi2 = 14.26, Pc = 0.0042, R.R. = 11.5). In the B51 allele genotyping, 11 out of 15 B51-positive patients were B*5101 and the remaining four were B*5108, whereas all of 5 normal controls were B*5101, showing significant association of each allele with Beh?et's disease. No significant difference was observed between the patient and control groups in the HLA class II allelic distribution. This study revealed a strong association of Beh?et's disease in Italian with B*5108 as well as B*5101, providing important insight into the molecular mechanism underlying an HLA association with Beh?et's disease.     

HLA-B*51 and B*15 alleles confer predisposition to Behçet's disease in Moroccan patients

HLA class I polymorphism in Moroccan patients with Beh?et's disease has not been investigated so far. In this study, HLA-B* phenotype frequencies were analyzed in 86 unrelated Moroccan patients (45 males, 41 females) and 111 ethnically matched healthy controls. The predisposing effect of the B*51 was confirmed (30.2% in patients and 15.3% in controls, OR = 2.39, 95% CI [1.2-4.8], p = 0.015). It was mostly observed in males with young age at disease onset (OR= 5.5 [1.9-15.9], p = 0.002 compared to controls). The Moroccan BD group also presented a previously unknown association with HLA-B*15 (25.6% of patients versus 11.7% of controls, OR = 2.59 [1.2-5.5], p = 0.014), both in females and in males with late-onset of the disease. Altogether, the B*15 and/or B*51 alleles were expressed in 55.8% of patients compared to 27% of controls (OR = 3.4 [1.9-6.2], p < 10-4, Pc = 0.003). Our data indicate HLA-B effects on BD pathogenesis should be considered separately for men and women.     

HLA class I genotyping including HLA-B*51 allele typing in the Iranian patients with Behçet's disease

It is well known that Beh?et's disease (BD) is strongly associated with human leukocyte antigen (HLA) B51 in many ethnic groups. However, there has been no published report as yet with respect to this association among the Iranian people. Furthermore, since it is now known that the B51 antigen can be encoded by 21 alleles, B*5101-B*5121, we performed HLA-B*51 allele typing as well as HLA class I genotyping of 48 Iranian patients with this disease. As a result, the frequency of the B*51 allele was significantly higher (62.1%) in the patient group as compared with the ethnically matched control group (31.8%) (Pc=0.067, R.R.=3.51). In the genotyping of B*51 alleles, 33 out of the 36 B*51-positive patients possessed B*5101 and the remaining 3 carried B*5108. This study revealed that Iranian patients with BD also had a strong association with HLA-B51. In addition, this significantly high incidence of HLA-B*51 was found to be caused by an increase in both the HLA-B*5101 and HLA-B*5108 alleles. However, there was no significant difference in the HLA-B*51 allelic distribution between the patient and control groups.     

A weak association of HLA-B*2702 with Behçet's disease

This study aimed to analyse the association of HLA-B alleles other than -B51 with Beh?et's disease (BD). We also investigated the frequency of HLA-B alleles sharing the same natural killer cell immunoglobulin-like receptor (KIR) binding sequence with HLA-B51. Broad-genotyping of HLA-B locus by PCR-SSOP in 174 Turkish BD patients and 191 healthy controls confirmed the strong association of B*51 with BD (60.9% in BD patients, 24.6% in healthy controls, OR = 4.78). No other HLA-B allele was identified showing an association with BD after adjusting for multiple testing or by using relative predispositional effects (RPE) analysis after the deletion of B*51. HLA-B alleles reacting with the sequence specific oligonucleotide probe 23, which corresponds to the KIR binding site of B*51, were found to be positive in 127 BD patients (73%) and 90 controls (47%) (OR = 3.03, 95% CI 2-4.7). The repeated RPE analysis after separating HLA-B alleles carrying B51-KIR binding sequence as distinct alleles within a broad-type allele group revealed B*2702 allele as the only allele showing an association with BD after the deletion of B*51. Selective increase of B*2702, the only B*27 allele carrying the same KIR binding sequence with B*51, warrants investigation of the possibility of interaction of HLA molecules with KIRs on NK or other T cells in the pathogenesis of BD.     

Re-evaluation of heterogeneity in HLA-B*510101 associated with Behçet's disease

Beh?et's disease (BD) is a chronic inflammatory disease characterized by oral aphthous ulcers, genital ulcers, uveitis and skin lesions. Etiology and pathogenesis of BD are not fully elucidated, but the association with human leukocyte antigen (HLA)-B51 or B*5101 has been repeatedly reported. Previous studies have shown that there are few sequence variations in the protein-coding region of B51, while there is a report on many variations in the 5'-flanking region and intron. In this study, HLA-B*5101 gene from 37 individuals including Japanese, Turkish, Jordanian and Iranian patients and healthy controls were fully sequenced to further clarify the B*5101 gene in association with BD. We found that all the patients and healthy controls carried B*510101 with no variation in the 5'-flanking region, exon and intron. However, seven polymorphisms were found in the 3'-flanking region. These polymorphisms composed of six haplotypes that were shared and stretched over the ethnic groups, suggesting that the susceptibility to BD was conferred by the B*510101 itself and not by any genes in linkage disequilibrium with B*510101. In addition, phylogenetic analyses of B*510101 showed that the 3'-flanking sequences followed an evolutional divergence differently from that of the other regions, implying that a unifying selection might operate to conserve B*510101.     

HLA-B phenotype modifies the course of Behçet's disease in Moroccan patients

In Moroccan patients, predisposition to Beh?et's disease is associated with HLA-B*51, mostly in males with young age at disease onset. In addition, the disease is associated with B*15 both in females and in males with late disease onset. We analyzed the clinical presentation, the severity and the course of the disease in 86 Moroccan patients according to their HLA-B phenotype. The presence of the B*51 or B*15 did not predispose to a particular clinical manifestation, nor to a more severe presentation of the disease. By contrast, outcome of the disease significantly differed depending on HLA-B phenotype, with an increase of symptoms in most B*51+ patients and in half of B*15 patients, and a remission or a decrease of symptoms in all B*51-B*15- patients. This variable course was mostly observed for ocular lesions, skin lesions, articular symptoms, and neurological symptoms. These data may suggest that treatment should be given early in the course of the disease in B*51 or B*15-positive patients in order to stabilize the inflammatory process.     

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.     

HLA-B*27 allele associated to Behçet's disease and to anterior uveitis in Moroccan patients

Human leukocyte antigen HLA-B51 is the most strongly associated gene with Beh?et disease (BD) in different ethnic populations. We analyze the influence of HLA-B alleles in BD predisposition in Moroccan population and its association with clinical manifestations. The HLA-B phenotype frequencies were analyzed by serologic HLA class I typing and by polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) reverse dot blot hybridization in 120 unrelated Moroccan patients: all of whom fulfilled the international study group criteria for Beh?et's disease, and in 112 ethnically matched healthy controls. Besides HLA-B*51 allele (20%), a significant increased frequency of the HLA-B*27 allele was found in Moroccans patients with Beh?et's disease when compared to controls (13.3% of patients versus 2.7% of controls, chi square =?8.75, OR =?5.59, 95% IC [1.58-19.75] and particularly in the patients who presented an anterior uveitis (25% vs. 5.5%, p 相似文献   

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.     

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.     

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.     

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.     

New insights of HLA class I association to Behçet's disease in Portuguese patients

Human leukocyte antigen (HLA)-B*51 is a well-known genetic factor associated with Beh?et's disease (BD). To analyse the influence of HLA-B*51 and other HLA class I alleles in BD susceptibility in a Portuguese population and its association with disease severity, we studied 78 BD patients and 208 healthy controls. The patients were classified into two severity groups as described by Gul et al. As expected, a higher frequency of HLA-B*51 was found. The frequency of HLA-Cw*16 alleles was significantly higher in patients. Regarding severity, HLA-B*27 frequency was higher in the severe group compared with controls and with the mild group. Thus, HLA-B*51 and HLA-Cw*16 seem to confer susceptibility to BD in this patients. HLA-B*27 may be important as a prognostic factor.     

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.     

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.     

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.     

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.     

Behçet's disease from the aspect of autoinflammatory disease

Beh?et's disease is a systemic inflammatory disease presented with recurrent oral aphtha, cutaneous manifestations, uveitis, and genital ulcer. The etiology of Beh?et's disease is still unknown, but both genetic background and environmental factors are thought to be important in the pathogenesis of Beh?et's disease. Beh?et's disease has long been regarded as a Th1 type autoimmune disease, because of the association with HLA-B51 and hyperreactivity against streptococcal antigen. However, it was recently found that Beh?et's disease and autoinflammatory diseases share several clinical features. Furthermore, increased activity of neutrophils and elevated levels of interleukin-1β are observed in both Beh?et's disease and autoinflammatory diseases. The relationship between Beh?et's disease and autoinflammatory diseases, especially Familial Mediterranean fever, is speculated, because both diseases are prevalent in the Mediterranean basin and treated with colchicine. Genetic researches on Beh?et's disease and FMF suggest that the MEFV gene mutated in Familial Mediterranean fever is a probable susceptibility gene for Beh?et's disease. Although many observations suggest that Beh?et's disease might be autoinflammatory, there is evidence implying autoimmune pathogenesis of Beh?et's disease. For example, some symptoms of Beh?et's disease is treated with T cell suppressing agents. Recent data suggest that a novel subset of T cells, Th17, plays a crucial role in pathogenesis of Beh?et's disease, and genome-wide association researches verified it. IL-17, which is the secreted from of Th17 activates neutrophils. Hence, IL-17 might cause the symptoms resembling autoinflammatory diseases. Recently, Anti-IL-1 treatment proved to be effective and other susceptibility genes are being investigated. These new findings will shed light on the long-sought pathogenesis of Beh?et's disease.     

New insights in the clinical understanding of Behçet's disease

Behçet''s disease is a chronic relapsing multisystemic inflammatory disorder characterized by four major symptoms (oral aphthous ulcers, genital ulcers, skin lesions, and ocular lesions) and occasionally by five minor symptoms (arthritis, gastrointestinal ulcers, epididymitis, vascular lesions, and central nervous system symptoms). Although the etiology of Behçet''s disease is still unknown, there have been recent advances in immunopathogenic studies, genome-wide association studies, animal models, diagnostic markers, and new biological agents. These advances have improved the clinical understanding of Behçet''s disease and have enabled us to develop new treatment strategies for this intractable disease, which remains one of the leading causes of blindness.