Behçet's disease, the Silk Road and HLA-B51: historical and geographical perspectives

Polymorphisms of Promoter Region of TNF-α Gene in Iranian Azeri Turkish Patients with Behçet's Disease

Behçet's disease (BD) is a complex chronic relapsing inflammatory disorder of unknown etiology. Alterations of the tumor necrosis factor (TNF) expression related to the polymorphic alleles of TNF gene may implicate a pathogenetic role in increased activity of this cytokine in BD. A current study aimed at investigating the possible association between BD and its clinical features in Iranian Azeri Turks with two functional TNF-α gene polymorphisms (at the positions of -238 and -857). A total number of 166 Iranian subjects were enrolled into two different groups; patients with BD (n = 64), and ethnically matched healthy controls (n = 101). The genotype distributions of BD patients and healthy controls were determined. The frequency of TNF-α -857C allele was significantly higher in Behçet's patients than that of healthy controls (P = 0.001; odds ratio [OR] = 2.616; 95% confidence interval [CI] = 1.129-6.160), whereas the frequency of TNF-α -238A allele was similar in both groups. The sole TNF-α haplotype-857C-1031C, was associated with an increase in the risk of developing BD. The TNF-α -857C allele was considerably associated with BD in this cohort. The findings of this study, collectively, indicate that TNF-α -857C-1031C haplotype located in the promoter region of the gene could exert major influence on the susceptibility to BD.

Update on the Medical Management of Gastrointestinal Behçet's Disease

Behçet's disease (BD) is a multisystemic disorder of unknown etiology mainly defined by recurrent oral aphthosis, genital ulcers, and chronic relapsing bilateral uveitis, all of which represent the "stigmata" of disease. However, many other organs including the vascular, neurological, musculoskeletal, and gastrointestinal systems can be affected. The gastrointestinal involvement in Behçet's disease (GIBD), along with the neurological and vascular ones, represents the most feared clinical manifestation of BD and shares many symptoms with inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis. Consequently, the differential diagnosis is often a daunting task, albeit the presence of typical endoscopic and pathologic findings may be a valuable aid to the exact diagnosis. To date, there are no standardized medical treatments for GIBD; therefore therapy should be tailored to the single patient and based on the severity of the clinical features and their complications. This work provides a digest of all current experience and evidence about pharmacological agents suggested by the medical literature as having a potential role for managing the dreadful features of GIBD.

Association of TNFSF4 Polymorphisms with Vogt-Koyanagi-Harada and Behcet's Disease in Han Chinese

To investigate whether single nucleotide polymorphisms (SNPs) of the Tumor Necrosis Factor Superfamily 4 (TNFSF4) gene are associated with Vogt–Koyanagi–Harada (VKH) and Behcet’s disease (BD) in a Chinese Han population. A two-stage case control study was carried out in 1331 VKH, 938 BD and 1752 healthy controls. Ten TNFSF4 SNPs, including rs1234314, rs1234315, rs2205960, rs704840, rs2795288, rs844654, rs12039904, rs10912580, rs844665, and rs844644, were genotyped using the PCR-restriction fragment length polymorphism method. Genotype and allele frequencies were analyzed between cases and healthy controls using the X² or Fisher’s exact test and p values were corrected for multiple comparisons. We observed a significantly increased frequency of the TT genotype of rs1234315 in BD patients (Pc = 1.44 × 10⁻⁵, OR = 1.734, 95% CI = 1.398–2.151). The frequency of the TT genotype of rs12039904 was significantly higher in patients with VKH disease as compared to controls (Pc = 4.62 × 10⁻⁵, OR = 1.959, 95% CI = 1.483–2.588). Analysis of clinical manifestations in VKH disease and BD did not show an association with the TNFSF4 gene polymorphisms. The study suggests that the TNFSF4 gene may be involved in the susceptibility to VKH disease and BD in Han Chinese.

Identification of Novel Biomarkers for Behcet Disease Diagnosis Using Human Proteome Microarray Approach

Behcet disease (BD) is a chronic systemic vasculitis and considered as an autoimmune disease. Although rare, BD can be fatal due to ruptured vascular aneurysms or severe neurological complications. To date, no known biomarker has been reported for this disease, making it difficult to diagnosis in the clinics. To undertake this challenge, we employed the HuProt arrays, each comprised of ∼20,000 unique human proteins, to identify BD-specific autoantibodies using a Two-Phase strategy established previously. In Phase I, we profiled the autoimmunity on the HuProt arrays with 75 serum samples collected from 40 BD patients, 15 diagnosed autoimmune patients who suffer from Takayasu arteritis (TA; n = 5)), ANCA associated vasculitis (AAV; n = 5), and Sjogren's syndrome (SS; n = 5), and 20 healthy subjects, and identified 20 candidate autoantigens that were significantly associated with BD. To validate these candidates, in Phase II we constructed a focused array with these 20 candidate BD-associated antigens, and use it to profile a much larger cohort, comprised of serum samples collected from 130 BD patients, 103 autoimmune patients (i.e. 40TA, 40 AAV and 23 SS), and 110 healthy controls. This allowed us to validate CTDP1 (RNA polymerase II subunit A C-terminal domain phosphatase)as a BD-specific autoantigen. The association of anti-CTDP1 with BD patients was further validated using the traditional Western blotting analysis. In conclusion, anti-CTDP1 antibody serves a novel autoantibody for Behcet disease and is expected to help more accurate clinical diagnosis.

Association study of rs924080 and rs11209032 polymorphisms of IL23R-IL12RB2 in a Northern Chinese Han population with Behcet's disease

OBJECTIVES

Two genome-wide association studies (GWAS) have identified the IL-23 receptor- IL-12 receptor β2 (IL23R-IL12RB2) as the susceptibility genetic region in Turkish and Japanese population with Behçet's disease (BD). We investigated the association of this region with BD in a Northern Chinese Han population.

METHODS

A total of 407 patients with BD and 421 healthy controls were genotyped for single nucleotide polymorphisms (SNPs) rs924080 and rs11209032 using the Sequenom MassArray system.

RESULTS

Statistically significant associations with BD were detected at two SNPs namely, rs924080 and rs11209032, both, by allele analysis (OR=1.58, 95% CI=1.25-2.00, P_c=2.52×10^-4, and OR=1.45, 95% CI=1.19-1.76, P_c=3.46×10^-4, respectively), and genotype analysis (P_c=1.22×10^-3andP_c=1.77×10^-3, respectively). Significant differences were observed in the genotype frequency distribution for these SNPs under the additive, dominant and recessive models (all P_c<0.05). The haplotypes (AT and GC) formed by the two SNPs were associated with BD (all permutation P<0.05). A meta-analysis also appeared to support the association of the two SNPs with BD.

CONCLUSION

SNPs (rs924080 and rs11209032) of the IL23R-IL12RB2 region were found to be associated with BD in a Northern Chinese Han population.

Bibliometric analysis on global Behçet disease publications during 1980-2014: is there a Silk Road in the literature?

BACKGROUND

Behçet disease (BD) is a chronic and multisystemic vasculitis characterized with recurrent oral and genital ulcers, uveitis, arthritis and skin manifestations. The highest prevalence of the disease has been reported in regions historically involved in the Silk Road routes.

OBJECTIVE

We aimed to analyse Behçet literature and evaluate whether there is a concordance between ancient Silk Road regions and the distribution of publication productivity.

METHODS

The bibliometric analysis of the publications published during 1980-2014 using Thomson Reuters Web of Science database was performed. We generated infographics of productivity and also analysed the correlations among economical productivities, technological advancement levels and humanity index and productivity performances of 78 countries in Behçet literature.

RESULTS

Turkey ranked first in Behçet literature with 1837 articles followed by Japan and the USA. Turkey, Tunisia and Israel occupied the first three places in productivity. Significant correlations were noted between 2014 gross economic and technological indices and publication numbers of the countries. We found that European countries had high productivity, although they had low prevalence of BD. We detected no concordance between the productivity density of the countries and the ancient Silk Road routes.

CONCLUSION

Most publications were reported from developed countries although undeveloped or developing countries had higher prevalence of BD. Physicians in undeveloped and developing countries should be supported and encouraged to perform novel studies on BD.

Identification of susceptibility SNPs in IL10 and IL23R-IL12RB2 for Behçet's disease in Han Chinese

BACKGROUND

Although previous genome-wide association studies in various cohorts have identified several susceptibility loci underlying Behçet's disease (BD), this has not yet led to a breakthrough in the management of BD.

OBJECTIVE

This study aimed to further investigate the association of 26 candidate single nucleotide polymorphisms with previous genome-wide association studies-identified nearly positive P values (5.0 × 10^-8 < P < 1.0 × 10^-5) in Chinese Han patients with BD.

METHODS

A case-control association study was performed in 1206 patients with BD and 2475 healthy controls. Genotyping was performed using iPLEX Gold genotyping assay. Gene expression and cytokine production was quantified by real-time PCR and ELISA.

RESULTS

The results showed that significantly higher frequencies of the IL23R-IL12RB2/rs924080 TT genotype (P = 2.03 × 10^-8; odds ratio [OR] = 1.50), IL23R-IL12RB2/rs12141431 CC genotype (P = 2.18 × 10^-8; OR = 1.53), IL10/rs1800871 TT genotype (P = 5.88 × 10^-8; OR = 1.47), and IL10/rs3024490 TT genotype (P = 2.80 × 10^-5; OR = 1.34) were found in BD. Functional experiments showed an increased IL23R expression and IL-17 production in rs12141431/CC genotype carriers compared with GG genotype carriers. A decreased IL10 expression and IL-10 production was observed in rs3024490/TT genotype carriers as compared with GG genotype carriers.

CONCLUSIONS

Our findings not only confirmed the association of IL10/rs1800871 and IL23R-IL12RB2/rs924080 with BD but also identified 2 susceptibility single nucleotide polymorphisms in IL10 and IL23R-IL12RB2 (rs3024490 and rs12141431) with BD in Han Chinese.

Methylation Status of Alu and LINE-1 Interspersed Repetitive Sequences in Behcet's Disease Patients

Behcet's Disease (BD) is a multisystem chronic inflammatory disease. The pathology is believed to involve both genetic susceptibility and environmental factors. Hypomethylation leading to activation of interspersed repetitive sequences (IRSs) such as LINE-1 and Alu contributes to the pathologies of autoimmune diseases and cancer. Herein, the epigenetic changes of IRSs in BD were evaluated using combined bisulfite restriction analysis-interspersed repetitive sequences (COBRA-IRS). DNA from neutrophils and peripheral blood mononuclear cells (PBMCs) of BD patients with ocular involvement that were in active or inactive states and healthy controls were used to analyze LINE-1 and Alu methylation levels. For Alu sequences, significant differences were observed in the frequency of ^uC^uC alleles between PBMCs of patients and controls (p = 0.03), and between inactive patients and controls (p = 0.03). For neutrophils, the frequency of ^uC^uC was significantly higher between patients and controls (p = 0.006) and between inactive patients and controls (p = 0.002). The partial methylation (^uC^mC + ^mC^uC) frequencies of Alu between inactive patients and control samples also differed (p = 0.02). No statistically significant differences for LINE-1 were detected. Thus, changes in the methylation level of IRS elements might contribute to the pathogenesis of BD. The role of Alu transcripts in BD should be investigated further.

Association between Functional MICA-TM and Behcet's Disease: A Systematic Review and Meta-analysis

The relationships between polymorphisms of the trans-membrane(TM) region located in the major histocompatibility complex (MHC) class I chain-related gene A (MICA) and Behcet's disease (BD) have been discussed previously, however, the results were contradictory. In this study, we thoroughly assess whether MICA-TM gene variants are associated with BD by means of a systematic review and meta-analysis. Our study focused on the effects of polymorphisms of MICA-A4, A5, A5.1, A6, and A9 from the included articles. Sixteen previous original publications representing 1,555 BD patients and 2,086 unrelated healthy controls analyzed the association of BD with MICA-TM gene polymorphisms. For the five alleles, MICA-A6 showed a strongly positive correlation with BD patients and could be viewed as an increased risk factor of BD (OR = 2.34, 95%CI: 2.02-2.70). Furthermore, MICA-A4, A5, A5.1, and A9 exhibited negative associations with BD (OR = 0.71, 95%CI: 0.58-0.86; OR = 0.75, 95%CI: 0.63-0.90; OR = 0.63, 95%CI: 0.44-0.91; OR = 0.70, 95%CI: 0.58-0.84, respectively). Our meta-analysis confirmed MICA-A6 could be responsible for BD in three ethnic regions and should probably be treated as a risk factor for BD. MICA-A4, A5, A5.1, and A9 could be regarded as protective factors, especially in the Middle East and East Asia.

Behçet's disease physiopathology: a contemporary review

Behçet’s disease, also known as the Silk Road Disease, is a rare systemic vasculitis disorder of unknown etiology. Recurrent attacks of acute inflammation characterize Behçet’s disease. Frequent oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions are the most common manifestations. Inflammation is typically self-limiting in time and relapsing episodes of clinical manifestations represent a hallmark of Behçet’s disease. Other less frequent yet severe manifestations that have a major prognostic impact involve the eyes, the central nervous system, the main large vessels and the gastrointestinal tract. Behçet’s disease has a heterogeneous onset and is associated with significant morbidity and premature mortality. This study presents a current immunological review of the disease and provides a synopsis of clinical aspects and treatment options.

miR-23a, miR-146a and miR-301a confer predisposition to Vogt-Koyanagi-Harada syndrome but not to Behcet's disease

Ninety-eight miRNAs are involved in the immune response. However, the genetic roles of these miRNAs remain unclear in Behcet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome. This study aimed to explore the association and functional roles of copy number variants (CNV) in several miRNAs with BD and VKH syndrome. Genotyping of CNVs was examined by TaqMan PCR. The expression of miR-23a, transfection efficiency and cytokine production were measured by real-time PCR, flow cytometry or ELISA. First, replication and combined studies for miR-23a, miR-146a and miR-301a demonstrated a similar association with VKH syndrome (Combined: P = 5.53 × 10(-8); P = 8.43 × 10(-31); P = 9.23 × 10(-8), respectively). No association of CNVs of the above mentioned miRNAs was observed in BD patients. mRNA expression of miR-23a showed a positive association with its copy numbers. Additionally, individuals with high copy number of miR-23a show an increased production of interleukin-6 (IL-6), but not IL-8 and monocyte chemoattractant protein-1 (MCP-1) by stimulated PBMCs. miR-23a transfected ARPE-19 cells modulated the production of IL-6 and IL-8, but not MCP-1. Our results suggest that CNVs of miR-146a, miR-23a and miR-301a confer susceptibility to VKH syndrome, but not to BD. The contribution of miR-23a to VKH syndrome may be mediated by increasing the production of IL-6.

Intestinal Behçet's Disease: A True Inflammatory Bowel Disease or Merely an Intestinal Complication of Systemic Vasculitis?

Behçet's disease (BD) is a multi-systemic inflammatory disorder of an unknown etiology and shows a chronic recurrent clinical course. When the disease involves the alimentary tract, it is called intestinal BD because of its clinical importance. Intestinal BD is more frequently reported in East Asian countries than in Western or Middle Eastern countries. While any part of the gastrointestinal tract can be involved, the most common location of intestinal BD is the ileocecal area. A few, large, deep ulcerations with discrete border are characteristic endoscopic findings of intestinal BD. Currently, there is no single gold standard test or pathognomonic finding of intestinal BD. However, recently developed novel diagnostic criteria and a disease activity index have helped in assessing intestinal BD. As intestinal BD shares a lot of characteristics with inflammatory bowel disease, including genetic background, clinical manifestations, and therapeutic strategies, distinguishing between the two diseases in clinical practice is quite difficult. However, biologic agents such as anti-tumor necrosis factor α antibody shows a considerable efficacy similar to inflammatory bowel disease cases. It is important to distinguish and treat those two disease entities separately from the standpoint of precise medicine. Clinicians should require comprehensive knowledge regarding the similarities and differences between intestinal BD and inflammatory bowel disease for making an accurate clinical decision.

Epidemiology and treatment of angiolymphoid hyperplasia with eosinophilia (ALHE): A systematic review

BACKGROUND

Current knowledge of angiolymphoid hyperplasia with eosinophilia (ALHE) derives from retrospective reports and case series, leading to a nonevidence-based treatment approach.

OBJECTIVE

We sought to systematically review the literature relating to cutaneous ALHE to estimate its epidemiology and treatment outcomes.

METHODS

A literature search of PubMed, EMBASE, Web of Science, and Google Scholar was conducted. Articles detailing cases of histologically confirmed cutaneous ALHE were included.

RESULTS

In all, 416 studies were included in the review, representing 908 patients. There was no sex predominance among patients with ALHE. Mean age at presentation was 37.6 years. There was a significant association between presence of multiple lesions and pruritus, along with bleeding. Surgical excision was the most commonly reported treatment for ALHE. Treatment failure was lowest for excision and pulsed dye laser. Mean disease-free survival after excision was 4.2 years. There were higher rates of recurrence postexcision with earlier age of onset, longer duration of disease, multiple lesions, bilateral lesions, pruritus, pain, and bleeding.

LIMITATIONS

Potential for publication bias is a limitation.

CONCLUSIONS

Surgical excision appears to be the most effective treatment for ALHE, albeit suboptimal. Pulsed dye and other lasers may be effective treatment options. More studies are needed to improve the treatment of ALHE.

Not all the infected develop the disease - A "Lotus and Cactus" model

The immunogenetic dictum "not all the infected develop the disease" can best be explained by a "Lotus and Cactus" model. Lotuses grow in ponds and cacti in deserts: analogously, we can say that tubercle patient's lung (genetic makeup) functions as an ideal 'broth' for Mycobacterium tuberculosis (M.tb) germs to grow, but not the lungs of an endemic control. HLA association studies from Europe to Asia since 1983 till date, have shown a persistent HLA DR2 (15) association. Further, HLA DR2 and non-DR2 endemic controls showed disparate patterns of immune responses and gene expressions. The host and pathogen MHC diversities, Th1-Th2 paradigm and cytokine circuits all may play a crucial role in TB susceptibility. It is possible to decipher the protective immunity by controlling the known confounders - epidemiological, demographic, socio-biological and also host and pathogen diversities. This has become significant with our understanding on the 'out of Africa' migration and neolithic co-dispersal of M.tb with modern human. Divergence and expansion of various MHCs (eg HLA-DRB1*15, HLA-B*57) and non-MHC alleles in various continents might be responsible for the skewed transmission and distribution of the infectious diseases around the globe. The 'Lotus and Cactus' model proposed here exemplifies this. A holistic genetic epidemiology approach employing modern tools is the need of the hour to better understand infectious disease susceptibility.

The immunogenetics of Behçet's disease: A comprehensive review

Behçet's disease is a chronic multisystem inflammatory disorder characterized mainly by recurrent oral ulcers, ocular involvement, genital ulcers, and skin lesions, presenting with remissions and exacerbations. It is thought that both environmental and genetic factors contribute to its onset and development. Although the etiology of Behçet's disease remains unclear, recent immunogenetic findings are providing clues to its pathogenesis. In addition to the positive association of HLA-B*51, which was identified more than four decades ago, and which has since been confirmed in multiple populations, recent studies report additional independent associations in the major histocompatibility complex class I region. HLA-B*15, -B*27, -B*57, and -A*26 are independent risk factors for Behçet's disease, while HLA-B*49 and -A*03 are independent class I alleles that are protective for Behçet's disease. Genome-wide association studies have identified associations with genome-wide significance (P < 5 × 10(-8)) in the IL23R-IL12RB2, IL10, STAT4, CCR1-CCR3, KLRC4, ERAP1, TNFAIP3, and FUT2 loci. In addition, targeted next-generation sequencing has revealed the involvement of rare nonsynonymous variants of IL23R, TLR4, NOD2, and MEFV in Behçet's disease pathogenesis. Significant differences in gene function or mRNA expression associated with the risk alleles of the disease susceptibility loci suggest which genes in a disease-associated locus influence disease pathogenesis. These genes encompass both innate and adaptive immunity and confirm the importance of the predominant polarization towards helper T cell (Th) 1 versus Th2 cells, and the involvement of Th17 cells. In addition, epistasis observed between HLA-B*51 and the risk coding haplotype of the endoplasmic reticulum-associated protease, ERAP1, provides a clue that an HLA class I-peptide presentation-based mechanism contributes to this complex disease.

Interleukin-23 Receptor Gene Polymorphism May Enhance Expression of the IL-23 Receptor, IL-17, TNF-α and IL-6 in Behcet's Disease

Purpose

Recent studies identified an association between Behcet’s disease (BD) and the IL-23R gene polymorphism (rs17375018) in different populations. This study examined whether this IL-23R gene polymorphism is associated with enhanced inflammatory responses.

Methods

We recruited 27 BD patients and 32 controls with three genotypes. Peripheral blood mononuclear cells (PBMCs) were seeded with or without anti-CD3 and CD28. Cells were incubated for 24 hours, and then supernatants were collected and stored at −20◦C until analyzed. Levels of interferon (IFN)-γ, tissue necrosis factor (TNF)-α, interleukin (IL)-17 and IL-6 were detected by ELISA. IL-23R expression was assessed by quantitative real-time polymerase chain reaction (RT-PCR).

Results

The expression of IL-23R was significantly higher in both BD patients and healthy controls with the GG genotype compared to the AG and AA genotype with anti-CD3 and CD28 stimulation (all P-value < 0.05). Among the PBMCs cultured with anti-CD3 and CD28 stimulation, there was an elevated secretion of TNF-α, IL-6 and IL-17 in BD patients and healthy controls with the GG genotype. However, there was no significant change in secretion of IFN- γ in BD patients and healthy controls among the genotype of this IL-23R gene polymorphism.

Conclusions

The results suggest that the GG genotype of the rs17375018 variant in the IL-23R gene enhances pro-inflammatory cytokine responses.

Behçet disease and protein-losing enteropathy due to intestinal lymphangiectasia

We report an unusual case of a patient with Behçet's disease that developed protein-losing enteropathy due to intestinal lymphangiectasia.

Cardiac manifestations in Behcet's disease

Behcet's disease (BD) is a chronic inflammatory disorder, with vasculitis underlying the pathophysiology of its multisystemic effects. Venous pathology and thrombotic complications are hallmarks of BD. However, it has been increasingly recognised that cardiac involvement and arterial complications are also important aspects of the course of the disease. Cardiac lesions include pericarditis, endocarditis, intracardiac thrombosis, myocardial infarction, endomyocardial fibrosis, and myocardial aneurysm. Treatment of cardiovascular involvement in BD is largely empirical, and is aimed towards suppressing the vasculitis. The most challenging aspect seems to be the treatment of arterial aneurysms and thromboses due to the associated risk of bleeding. When the prognosis of cardiac involvement in BD is not good, recovery can be achieved through oral anticoagulation, immunosuppressive therapy, and colchicine use. In this review, we summarise the cardiovascular involvement, different manifestations, and treatment of BD.

Electron Transfer Flavoprotein Subunit Beta Is a Candidate Endothelial Cell Autoantigen in Behçet's Disease

Behçet’s disease (BD) is a chronic inflammatory disease with multisystem involvement, and it is listed as a rare disease in the United States but is common in the Middle East, China, and Japan. The aim of this study was to identify novel autoantigens in Chinese patients with BD. First, the candidate autoantigens were screened by Western blotting, and the sequences of putative antigens were identified by LC-MALDI-TOF/TOF mass spectrometry. Next, the screened protein was cloned, expressed and purified. Then, an optimized ELISA was developed, and the serological criteria were evaluated using a large number of confirmed patients. One antigen with a molecular weight of approximately 28 kDa was identified as electron transfer flavoprotein subunit beta (ETFB). Positive reactivity was detected in recombinant human ETFB sera from 38 of 92 BD patients (41 %) and 1 of 90 healthy controls (1 %).

Behçet's Disease: Do Natural Killer Cells Play a Significant Role?

Behçet's disease (BD) is a complex inflammatory disease, of unknown etiology. While disease pathogenesis remains unclear, a strong relationship between BD and HLA-B*51 has been established over the last 30 years. A number of theories exist regarding the cause of BD; however, few are able to account for the increased rates of HLA-B*51 positive individuals, particularly around the Mediterranean basin and Middle-East where the prevalence is highest. This review outlines current immunogenetic data on BD and the immunoregulatory role natural killer cells may play. It also describes the interaction of the killer immunoglobulin-like receptor - KIR3DL1 with its ligand Bw4, which is found on HLA-B51. Finally, CD94/NKG2D, MICA, and ERAP are outlined with regard to their potential roles in BD.

Association analysis of TGFBR3 gene with Behçet's disease and idiopathic intermediate uveitis in a Caucasian population

BACKGROUND

Transforming growth factor β (TGFβ) is an important immunoregulatory cytokine in regulatory T cell (Treg) and Th17-mediated pathology, including uveitis due to Behçet's disease (BD). Of the three isoforms, TGFβ2 is found at highest levels in the aqueous humour of uninflamed eyes. TGFβ signals through a cell-surface receptor comprising three subunits (TGFBR1, 2 and 3). TGFBR3 is considered necessary for TGFβ2 signal transduction, but not for other isoforms. A polymorphism in TGFBR3 (rs1805110) has previously been identified in Han Chinese patients with BD. We investigated the frequency of this polymorphism in a Caucasian population with BD and idiopathic intermediate uveitis (IIU).

METHODS

The single-nucleotide polymorphism (SNP) rs1805110 in TGFBR3 was genotyped in 75 BD patients, 92 IIU disease controls and 85 disease-free controls. The association with both diseases was analysed using Fisher's exact test.

RESULTS

No significant difference in rs1805110 allele or genotype frequency was observed. A low frequency of the T allele was observed (5.88% control, 9.33% BD, 10.33% IIU) with the TT genotype absent in patients with BD and IIU (1.18% control, 0% BD and 0% IIU). Stratification analysis according to clinical features of BD did not associate with the tested SNP.

CONCLUSIONS

RS1805110 is not associated with BD or IIU in Caucasian patients. The T allele frequency is consistent with that presented for Caucasian populations in the HapMap database (p>0.05). Our results differ from the previous analysis in Han Chinese patients (p<0.0001), however, the possibility of having a much smaller effect due to the low minority frequency cannot be excluded.

Annexin A2 as a target endothelial cell membrane autoantigen in Behçet's disease

Cell membrane proteins are believed to play a critical role in the pathogenesis of autoimmune diseases. However, few membrane autoantigens have been linked with Behçet's disease. Here, a cell-chip was performed to identify autoantibody target cells, and the suspected autoantigens were detected using immunoblotting. The amino acid sequences of the detected proteins were determined using LC-MALDI-TOF/TOF. Putative proteins were recombinantly expressed and purified, and a corresponding ELISA was developed and clinically validated using real clinical samples. It was found that a 36-kDa membrane protein--annexin A2--was detected in approximately one-third of the patients' blood circulation. The immunohistochemistry results showed that annexin A2 was highly expressed in vascular endothelial cells. Moreover, vascular involvement was significantly higher in the anti-annexin A2 antibody-positive group versus the anti-annexin A2 antibody-negative group among all the clinical samples analyzed, indicating that annexin A2 is a novel endothelial cell membrane antigen involved in Behçet's disease.

Behcet's disease presenting with recurrent ocular, oral, and scrotal inflammatory lesions in a young Tanzanian man: a case report

KEY CLINICAL MESSAGE

Behcet's disease (BD) is a rare condition which is diagnosed clinically. Only few cases have been reported in sub-Saharan Africa. We report a Tanzanian male who presented with typical features of BD and was successfully treated. There should be an increase in awareness on BD to improve the management.

Effectiveness and tuberculosis-related safety profile of interleukin-1 blocking agents in the management of Behçet's disease

Behçet's disease (BD) is a multi-systemic disorder of unknown etiology characterized by relapsing oral-genital ulcers, uveitis, and involvement of the articular, gastrointestinal, neurologic, and vascular systems. Although the primum movens of this condition remains unknown, a tangled plot combining autoimmune and autoinflammatory pathways has been hypothesized to explain its start and recurrence. In-depth analysis of BD pathogenetic mechanisms, involving dysfunction of multiple proinflammatory molecules, has opened new modalities of treatment: different agents targeting interleukin-1 have been studied in recent years to manage the most difficult and multi-resistant cases of BD. Growing experience with anakinra, canakinumab and gevokizumab is discussed in this review, highlighting the relative efficacy of each drug upon the protean BD clinical manifestations. Safety and tolerability of interleukin-1 antagonists in different doses have been confirmed by numerous observational studies on both large and small cohorts of patients with BD. In particular, the potential for Mycobacterium tuberculosis reactivation and tuberculosis development appears to be significantly lower with interleukin-1 blockers compared to tumor necrosis factor-α inhibitors, thus increasing the beneficial profile of this approach.

Epigenome-wide scan identifies a treatment-responsive pattern of altered DNA methylation among cytoskeletal remodeling genes in monocytes and CD4+ T cells from patients with Behçet's disease

OBJECTIVE

The pathogenesis of Behçet's disease (BD), an inflammatory disease with multisystem involvement, remains poorly understood. This study was undertaken to investigate whether there are DNA methylation abnormalities in BD that might contribute to the pathogenesis of the disease.

METHODS

We examined genome-wide DNA methylation patterns in monocytes and CD4+ T cells from 16 male patients with untreated BD and age, sex, and ethnicity-matched healthy controls. Additional samples were collected from 12 of the same BD patients after treatment and achievement of disease remission. Genome-wide DNA methylation patterns were assessed using the Infinium HumanMethylation450 BeadChip array, which includes >485,000 individual methylation sites across the genome.

RESULTS

We identified 383 CpG sites in monocytes, and 125 in CD4+ T cells, that were differentially methylated between BD patients and controls. Bioinformatic analysis revealed a pattern of aberrant DNA methylation among genes that regulate cytoskeletal dynamics, suggesting that aberrant DNA methylation of multiple classes of structural and regulatory proteins of the cytoskeleton might contribute to the pathogenesis of BD. Further, treatment of BD modified the differences in DNA methylation observed in patients compared to controls; indeed, among CpG sites that were differentially methylated after disease remission versus before treatment, there was widespread reversal of the direction of aberrant DNA methylation observed between the patient and control groups.

CONCLUSION

The results of this epigenome-wide study-the first such study in BD-provide strong evidence that epigenetic modification of cytoskeletal dynamics underlies the pathogenesis of BD and its response to treatment.

Identification of prohibitin as an antigen in Behcet's disease

OBJECTIVE

This study is intended to screen potential antigen for Behcet's disease (BD) by using human microvascular endothelial cells (HUVEC).

METHODS

Following cell-based indirect immunofluorescence assay with sera from BD patients, proteins extracted from HUVEC were separated and detected by Western blotting. Then the target protein was identified by LC-MALDI-TOF/TOF, the recombinant target protein was expressed, purified and then used as coating antigen to test the prevalence of autoantibodies in patient's sera.

RESULTS

The Western blotting result showed that some patients' sera could react with a protein band with about 30 kDa of molecular weight, which was further identified as prohibitin by mass spectrometry. The prevalence of serum antibodies against recombinant human prohibitin was detected in 16 of 58 BD patients (28%) but none in healthy controls.

The prevalence of Behçet's disease in a city in Central Anatolia in Turkey

BACKGROUND

The prevalence of Behçet's disease (BD) is much higher in countries along the ancient Silk Route, extending from Japan to Mediterranean countries including Turkey, than in northern Europe and the USA.

OBJECTIVES

The present study aimed to investigate the prevalence of BD in Kayseri, a city in Central Anatolia in Turkey.

METHODS

This study investigated cross-sectional prevalences of BD in individuals aged >10 years in Kayseri, Turkey, in two stages. The first stage aimed to identify individuals with recurrent oral ulcers (ROUs) through home visits, and the second stage aimed to further examine those with ROUs for the presence of other BD-related manifestations under hospital conditions. The study was conducted using the criteria defined by the International Study Group for Behçet's Disease. The sample size was determined to be 4697 with an expected sampling error of 5.5 per 10,000, with a 95% confidence interval. A standard questionnaire was administered to a total of 5218 individuals.

RESULTS

A history of ROU was recorded in 470 (9.0%) of the 5218 residents, and a previous diagnosis of BD was recorded in nine individuals. The prevalence rate of BD was estimated as 17 cases per 10,000 population in Kayseri, Turkey.

CONCLUSIONS

The present study contributes towards estimations of prevalences of BD in Turkey and towards raising public awareness about the disease. It also supports previous studies that have reported the world's highest prevalences of BD in Turkey.

Gender disparities in ocular inflammatory disorders

Ocular inflammatory disorders disproportionately affect women, and the majority of affected women are of childbearing age. The role of sex or reproductive hormones has been proposed in many other inflammatory or autoimmune disorders, and findings from non-ocular autoimmune diseases suggest a complex interaction between sex hormones, genetic factors and the immune system. However, despite the age and sex bias, factors that influence this disparity are complicated and unclear. This review aims to evaluate the gender disparities in prevalence, incidence and severity of the most common infectious and non-infectious ocular inflammatory disorders.

MDR1 C3435T polymorphism associated with the development of clinical features in Behçet's disease in Iranian Azeri Turkish patients

BACKGROUND

Behçet's disease (BD) is a systemic vasculitis of unknown cause with a higher prevalence along the ancient Silk Road. Behçet's occasional familial aggregation and its close association with genes of major histocompatibility complexes justify that genetic factors play an important role in the development of the disease. In this study, we evaluated the association of multidrug resistance (MDR1) C3435T polymorphism with the severity of BD.

METHOD

We investigated the distribution of MDR1 C3435T polymorphism in 69 patients from the Iranian Azeri Turks group with BD and 92 ethnically sex-matched healthy controls, via the polymerase chain reaction-restriction fragment length polymorphism technique.

RESULT

Although there was no significant association of MDR1 C3435T polymorphism between two groups of patients and healthy controls, our data showed a substantial association of CC genotype with the development of several clinical features, including erythema nodosum (P = 0.001, OR = 2.686, 95%), pseudofolliculitis (P = 0.002, OR = 2.812, 95%), and skin lesions (P = 0.040, OR = 1.934, 95%).

CONCLUSION

These results suggest that CC genotype is a risk factor for the development of some clinical features of BD in patients from the Iranian Azeri Turk ethnic group.

Genetic variations of IL-12B, IL-12Rβ1, IL-12Rβ2 in Behcet's disease and VKH syndrome

Purpose

To investigate the associations of single nucleotide polymorphisms (SNPs) of three genes (IL-12B, IL-12Rβ1 and IL-12Rβ2) in Behcet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome in a Chinese Han population.

Methods

A total of 806 BD cases, 820 VKH patients, and 1600 healthy controls were involved in this study. The first investigation included 400 BD patients, 400 VKH cases, and 600 healthy individuals. A second confirmatory study included a separate set of 406 BD patients, 420 VKH cases and another 1000 normal controls. Genotyping was carried out by PCR-restriction fragment length polymorphism assay and results were validated by using direct sequencing. The χ2 test was performed to compare the allele and genotype frequencies between cases and healthy controls.

Results

This study comprised two phases. In the first phase study, a significantly increased frequency of the rs3212227/IL-12B genotype CC and C allele was found in BD patients as compared to controls (Bonferroni corrected p value (p_c) = 0.009, OR 1.8; p_c = 0.024, OR 1.3, respectively). Moreover, the frequency of the C allele of rs3212227/IL-12B was also significantly increased in VKH patients (p_c = 0.012, OR 1.3, 95% CI 1.1 to 1.6). No associations were found for the other seven tested SNPs either in BD or VKH disease. The second study as well as the combined data confirmed the significant association of rs3212227/IL-12B with BD (CC genotype: combined p_c = 6.3×10⁻⁷, OR = 1.8; C allele: combined p_c = 2.0×10⁻⁵, OR = 1.3, respectively) and the C allele frequency of rs3212227/IL-12B as the risk factor to VKH patients (combined p_c = 2.5×10⁻⁵, OR 1.3, 95% CI 1.2 to 1.5).

Conclusions

Our study revealed that the IL-12B gene is involved both in the susceptibility to BD as well as VKH syndrome.

Gender Differences in Behçet's Disease Associated Uveitis

Behçet's disease is a systemic vasculitis of unknown etiology, characterized by oral and genital ulceration, skin lesions, and uveitis as well as vascular, central nervous system, and gastrointestinal system involvement. It is prevalent in the Middle East, Mediterranean, and Eastern Asia. The aim of this review is to evaluate the gender differences in clinical manifestations of Behçet's disease, treatment responses, mortality, and morbidity. Behçet's disease has been reported to be more prevalent in males from certain geographic regions and particular ethnic groups; however, recent reports indicate more even gender distribution across the world. There are gender differences in clinical manifestations and severity of the disease. Ocular manifestations, vascular involvement, and neurologic symptoms are more frequently reported in male patients whereas oral and genital ulcers, skin lesions, and arthritis occur more frequently in female patients. The disease can have a more severe course in males, and overall mortality rate is significantly higher among young male patients.

[Parenchymal neuro-Behcet's disease. Clinical and paraclinical characteristics, a report of 40 cases]

OBJECTIVE

Describe the clinical and paraclinical characteristics of parenchymal neuro-Behcet's disease.

METHODS

This is a prospective, descriptive study, concerning 40 patients with parenchymal neuro-Behcet's disease. The patients were followed during 3 years, benefited a thorough physical examination and paraclinical made of inflammatory laboratory tests, infectious serology, serum/CSF autoimmunity assessment, brain/spine MRI and evoked potentials. We also evaluated the frequency of HLA-B51.

RESULTS

We identified 22 men and 18 women. The average age was 32 years. The beginning was poly-symptomatic in 65% cases. Twenty-eight patients (70%) reported a decrease in visual acuity, 40% (16 cases) associated with uveitis, 33 cases (82.5%) complained of headache and 11 cases (27.5%) with dizziness. Inaugural signs consisted of motor disorders (50%) and balance disorders (40%). The inflammatory serum markers were positive in 75% and oligoclonal bands present in CSF were found in 7 patients. Infracentimetric demyelinating lesions in MRI study were located in the brainstem (52.5%), the subcortical white matter (40%), the periventricular region (42.5%), cerebellum (32.5%), basal ganglia (30%), internal capsule (25%) and corpus callosum (12.5%). The HLA-B51 was found in 53% of cases.

CONCLUSION

Behçet's disease mainly affects young male. The neurological complications are highly polymorphic, involving severe vital or functional prognosis.

Behçet's syndrome pathophysiology and potential therapeutic targets

Behçet syndrome is a systemic inflammatory disorder characterized by multiorgan involvement such as oral and genital ulcers, uveitis, skin lesions as well as by less frequent, but often more severe, central nervous system and vascular manifestations. The pathogenetic mechanisms are still incompletely known; however the interaction between a specific genetic background and environmental or infectious factors certainly contributes to the immune dysregulation that characterizes this disease. The discovery of new immunological pathways in Behçet syndrome pathogenesis may help us to set up new treatments. In this review, we will focus our attention on the possible mechanisms underlying Behçet syndrome pathogenesis and their potential role as novel therapeutic targets.

Ethnicity and association with disease manifestations and mortality in Behçet's disease

BACKGROUND

Behçet's disease (BD) significantly increases morbidity and mortality. BD mainly affects young adults with a peculiar geographical distribution. It has been suggested that BD varies in its phenotypic expression in different ethnic groups.

METHODS

We investigated potential ethnicity-related differences relative to phenotype and prognosis of BD patients in a French multiethnic country. We included 769 consecutive patients fulfilling the international criteria of classification for BD, in the 3 largest ethnic groups of our cohort [European (n = 369), North African (n = 350) and sub Saharan African (n = 50)]. Factors that affect prognosis were assessed by multivariate analysis.

RESULTS

535 (69.6%) patients were male and the median (IQR) age at diagnosis was of 30.9 (24.9-37.2) years. Sub Saharan African BD patients had a higher frequency of CNS involvement (48% vs 32.3% vs 29.5%, p = 0 .035), a higher rate of death (12% vs 6% vs 3.5%, p = 0.029) and a lower frequency of HLA B51 allele (29.4% vs 49.2% vs 55.8%, p = 0.009) compared to those from North Africa and Europe, respectively. Multivariate analysis showed that male gender (HR: 5.01, CI: 1.51-16.65), cardiovascular involvement (HR: 2.24, CI: 1.15-4.36), and sub Saharan African origin (HR 2.62 (0.98-6.97) were independently associated with mortality. The 15-year mortality rate was of 19%, 9% and 6% in sub Saharan African, North African and European BD patients, respectively (p = 0.015).

CONCLUSION

We reported ethnicity-related differences with respect to phenotype of BD. Sub Saharan Africans patients exhibited a worse prognosis.

Polymorphisms of interleukin 6 and interleukin 10 in Egyptian people with Behcet's disease

Cytokines play critical roles in the pathogenesis of Behçet's disease (BD). They mediated many of the effectors and regulatory functions of immune and inflammatory responses. Many studies have linked Interleukin-6 (IL-6) and Interleukin-10 (IL-10) pathologically to BD. Thus, this study aimed to investigate the associations between IL-6 and IL-10 promoter single-nucleotide polymorphisms (SNPs) and the susceptibility to BD and their implication on plasma levels. We genotyped IL-6 -174 G/C (rs1800795) using Mutagenically Separated Polymerase Chain Reaction PCR (MS-PCR) and IL-10 -1082 G/A (rs1800896) and -819 C/T (rs1800871) using Sequence Specific Primer PCR (SSP-PCR) in 87 Egyptian patients and 97 controls. The plasma levels of IL-6 and IL-10 were measured using Enzyme-linked Immunosorbent Assay (ELISA). Significant increase in the frequency of -1082 GG genotype (P<0.05, OR=2.25, 95%CI=1.03-4.91) and significant decrease in the frequency of -1082 GA genotype (P<0.05, OR=0.53, 95%CI=0.29-0.96) was demonstrated in BD patients compare to controls. Patients with genital ulcer had significantly lower frequency of -1082 GG (P<0.05, OR 0.2, 95% CI=0.04-0.99) and G allele (P<0.05, OR=0.28, 95%CI=0.08-0.93), while patients with ocular manifestations had significantly higher frequency of -1082 G allele (P<0.01, OR=2.28, 95%CI=1.19-4.36). BD patients had significantly higher level of IL-6 (P<0.001) and significantly lower level of IL-10 (P<0.001) compared to controls. The changes in the level of cytokines were independent of any genotype of IL-6 or any genotype/haplotype of IL-10. Patients with active disease state had significantly higher level of IL-6 compared to patients in remission (P<0.05). In conclusion, our preliminary study indicates that the polymorphism at IL-10 -1082 G/A may play a role in BD susceptibility. The significant increase in IL-6 level and the significant decrease in IL-10 level in BD patients were independent of any particular genotype in IL-6 or any particular genotype/haplotype in IL-10.

Intercellular adhesion molecule-1 polymorphisms in patients with Behçet disease: a meta-analysis

OBJECTIVES

To examine the association between the Intercellular adhesion molecule-1 (ICAM1) Polymorphisms and Behçet's disease.

METHODS

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials for original studies up to July 31, 2012 were searched for relevant studies. All pooled odds ratios (ORs) were derived from either fixed or random-effects model with its 95% confidence intervals (CI).

RESULTS

Five studies met the inclusion criteria. Overall, ICAM1 E469 (OR = 1.45, 95% CI = 1.06-1.97), genotype ICAM1 469 E/E (OR = 1.45, 95% CI = 1.09-1.94), ICAM1 241 G/R (OR = 3.65, 95% CI = 1.69-7.89), had significant associations with Behçet's disease. A significant association was found between the presence of skin lesions and genotype ICAM1 469 E/E (OR = 3.52, 95% CI = 1.62-7.66).

CONCLUSIONS

Behçet's disease was associated with the ICAM1 E469, genotype ICAM1 469 E/E, ICAM1 241 G/R polymorphisms in different ethnic groups. Among patients, genotype ICAM1 469 E/E had a significant association with skin lesion.

Causal attributions about disease onset and relapse in patients with systemic vasculitis

OBJECTIVE

Patients vary in their beliefs related to the cause of serious illness. The effect of these beliefs among patients with systemic vasculitis is not known. Our study aimed to describe causal attributions about disease onset and relapse in systemic vasculitis and to examine whether causal beliefs differ by type of vasculitis or are associated with negative health outcomes.

METHODS

Patients with vasculitis were recruited to complete an online questionnaire. Categories of causal beliefs were assessed with the Revised Illness Perception Questionnaire (IPQ-R). Differences in beliefs about disease onset versus relapse were compared across different forms of vasculitis. Causal beliefs were assessed in association with several health outcomes including fatigue, functional impairments, and personal understanding of the condition.

RESULTS

The questionnaire was completed by 692 patients representing 9 forms of vasculitis. The majority (90%) of patients had beliefs about the cause of their illness. Causal attributions were highly variable, but altered immunity and stress were the most commonly agreed-upon causal beliefs. Frequencies of causal beliefs were strikingly similar across different forms of vasculitis, with a few notable exceptions primarily in Behçet disease. Beliefs differed about causes of disease onset versus relapse. Specific beliefs about disease onset and relapse were weakly associated with fatigue, functional impairments, and understanding of the condition.

CONCLUSION

Patient beliefs related to the cause of systemic vasculitis are highly variable. Patterns of causal beliefs are associated with important negative health outcomes. Clinicians who care for patients with vasculitis should be mindful of these associations and consider asking about patients' causal beliefs.

Diagnosis and management of Neuro-Behçet's disease: international consensus recommendations

Neuro-Behçet’s disease (NBD) is one of the more serious manifestations of Behçet’s disease (BD), which is a relapsing inflammatory multisystem disease with an interesting epidemiology. Though NBD is relatively uncommon, being potentially treatable, neurologists need to consider it in the differential diagnosis of inflammatory, infective, or demyelinating CNS disorders. Evidence-based information on key issues of NBD diagnosis and management is scarce, and planning for such studies is challenging. We therefore initiated this project to develop expert consensus recommendations that might be helpful to neurologists and other clinicians, created through an extensive literature review and wide consultations with an international advisory panel, followed by a Delphi exercise. We agreed on consensus criteria for the diagnosis of NBD with two levels of certainty in addition to recommendations on when to consider NBD in a neurological patient, and on the use of various paraclinical tests. The management recommendations included treatment of the parenchymal NBD and cerebral venous thrombosis, the use of disease modifying therapies, prognostic factors, outcome measures, and headache in BD. Future studies are needed to validate the proposed criteria and provide evidence-based treatments.

Validity and agreement of uveitis experts in interpretation of ocular photographs for diagnosis of Behçet uveitis

Abstract Purpose: To evaluate agreement and estimate sensitivity and specificity of uveitis specialists' interpretation of ocular photographs in diagnosing Behçet uveitis.

METHODS

Fourteen Turkish uveitis specialists, masked to demographic and clinical features of patients, independently labeled ocular photographs (29 Behçet/30 other diagnoses) as "Behçet uveitis" or "non-Behçet." Level of agreement was evaluated using kappa statistics. Photographs were categorized based on ocular signs captured and performance of observers.

RESULTS

Exact agreement with the correct diagnosis was 56-81%. Seven reviewers correctly labeled more than 70% of photographs. Interobserver agreement among those 7 reviewers revealed moderate (κ = 0.41-0.60) or substantial (κ = 0.61-0.80) agreement in 76% of pairs. Smooth layered hypopyon, superficial retinal infiltrate with retinal hemorrhages, and branch retinal vein occlusion with vitreous haze were correctly recognized as Behçet uveitis by majority of reviewers.

CONCLUSIONS

There are ocular signs of Behçet disease that can be considered diagnostic even in the absence of any other clinical information.

IL10 polymorphisms associated with Behçet's disease in Chinese Han

OBJECTIVE

IL-10 is a potent anti-inflammatory cytokine that plays important roles in the pathogenesis of Behçet's disease (BD). Two genome-wide association studies have identified IL10 as a potential risk factor for BD. Here, we investigated the association between IL10 polymorphisms and BD in Chinese Han.

METHODS

407 BD patients and 679 healthy controls were enrolled, and genotyped by Sequenom MassArray system (Sequenom iPLEX assay, San Diego, CA).

RESULTS

The frequency of risk allele of rs1800871 was notably higher in BD patients than in controls (71.9% vs. 66.2%, OR: 1.30, 95%CI: 1.08-1.58, pc=0.024). Similarly, rs1518111, which showed strong linkage disequilibrium (r(2)=1) with allele rs1800871, was also associated with BD (pc=0.026). Rs3021094 was in association with BD in a dominant model (pc=0.035), and the haplotype (GACC) formed by rs1518111, rs3021094, rs3790622, and rs1800871 was associated with BD (pc=0.023). Results obtained from meta-analysis combined with our data showed that rs1800871 and rs1518111 were associated with BD.

CONCLUSION

IL10 may be the susceptibility gene for BD in Chinese Han population.