Interactions between IL17A, IL23R, and STAT4 polymorphisms confer susceptibility to intestinal Behcet's disease in Korean population

Assessment of IL-6 Pathway Inhibition in Gastrointestinal Behçet's Disease from Immunological and Clinical Perspectives

Behçet's disease is an autoinflammatory disorder characterized by relapsing and remitting vasculitis that can manifest in various forms, including gastrointestinal Behçet's disease (GIBD). Its complications (e.g., intestinal perforation) are among the primary causes of morbidity and mortality. GIBD pathogenesis involves the enhanced production of certain cytokines, e.g., tumor necrosis factor α and interleukin-6 (IL-6), which could serve as a target for potential therapies. This review provides an overview of GIBD, including the diagnosis and immunopathogenesis as it is currently understood, and evaluates the emerging role of the inhibition of IL-6 (classic and trans-signaling) as an alternative treatment option for patients with GIBD. Given the current paucity of data, we reflected on the potential of IL-6 inhibitors such as tocilizumab and olamkicept based on immunopathogenic considerations and available clinical data in patients with inflammatory bowel disease (IBD), in whom clinical response or remission was induced. The selective inhibition of IL-6 trans-signaling may bring new impetus to the development of this drug class, particularly regarding safety. Still, the benefits of IL-6 inhibitors for patients with GIBD need to be evaluated in appropriate proof-of-concept studies. The clinical outcomes of IL-6 inhibitors in IBD are promising and may suggest their potential relevance in GIBD.

Associations of IL-17 and IL-17 receptor polymorphisms with Behçet's disease in Denizli Province of Turkey

Although the etiopathogenesis of Behçet's disease is not known, studies conducted in different populations show that it is a multifactorial disease that is thought to develop as a result of the interaction of environmental and genetic factors. IL-17 is thought to induce the neutrophilic inflammation and the tissue damage mediated by immune response in patients. Polymorphisms in the gene region encoding IL-17 and IL-17R molecules may play a critical role in the pathogenesis of the disease and contribute to the elucidation of disease mechanism. We aimed to show the association of IL-17A, IL-17F, and IL-17RC polymorphisms and haplotypes in Behçet's disease patients and its clinical features. We genotyped IL-17A (rs4711998 (A/G), rs8193036 (C/T), rs2275913 (A/G), rs3819025 (A/G), rs8193038 (A/G), rs3804513 (A/T), rs1974226 (C/T), rs3748067 (C/T)); IL-17F (rs763780 (T/C), rs2397084 (T/C)); and IL-17R (IL-17RC) (rs708567 (C/T)) polymorphisms in 88 patients with Behçet's disease and 133 healthy controls using PCR-RFLP-based approach. The results of our study showed that polymorphisms of IL-17A, rs8193036 (C/T), rs3819025 (G/A), rs3804513 (A/T), IL-17F rs2397084 (T/C), and IL-17RC rs708567 (C/T) are associated with the susceptibility to the BD. When the haplotype distributions of all loci of IL-17Aand IL-17A/IL-17F together were examined and in contrast to the data obtained from the controls, the GTGGAACC (27.84%) and GTGGAACCTT (25.57%) have the highest frequencies. In conclusion, the allele and genotype frequency differences of the IL-17A, IL-17F, and IL-17R and haplotype frequencies between Behçet's disease and controls indicate that the genetic structure of Behçet's disease may be different.

Possible Association of Mutations in the MEFV Gene with the Intestinal Phenotype of Behçet's Disease and Refractoriness to Treatment

BACKGROUND

Mediterranean fever (MEFV) gene mutations are responsible for familial Mediterranean fever (FMF) and associated with other inflammatory diseases. However, the effects of MEFV gene mutations on intestinal Behçet's disease (BD) are unknown. In this study, we investigated these mutations and clinical features in patients with intestinal BD.

METHODS

MEFV gene analysis was performed in 16 patients with intestinal BD, 10 with BD without intestinal lesions, and 50 healthy controls. Clinical features of patients with intestinal BD were retrospectively assessed.

RESULTS

The rates of MEFV gene mutations in patients with intestinal BD, BD without intestinal lesions, and healthy controls were 75%, 50%, and 38%, respectively. Only 2 of 12 patients with intestinal BD harboring MEFV gene mutations (17%) were controlled without immunosuppressive treatment, while 8 patients (67%) required therapy with tumor necrosis factor (TNF) inhibitors. Among patients with intestinal BD without MEFV gene mutations (four patients), three (75%) were controlled by the administration of 5-aminosalicylic acid with or without colchicine, and one (25%) required TNF inhibitors. All patients who underwent intestinal resection had MEFV gene mutations. Immunohistochemical analysis and in situ hybridization with interleukin-1β (IL-1β) showed a high expression of IL-1β only in injured areas, suggesting that IL-1β may be involved in the formation of ulcers in patients with intestinal BD carrying MEFV gene mutations.

CONCLUSION

Mutations in the MEFV gene may be associated with intestinal lesions of BD and refractoriness to treatment.

Associations between interleukin 17A and 17F polymorphisms and asthma susceptibility: A meta-analysis

Owing to their role in inflammatory reactions and immunological responses as well as their chromosomal location, interleukin (IL) 17A and 17F are regarded as candidate causal genes associated with asthma. The aim of this study was to determine whether IL17 polymorphisms are associated with susceptibility to asthma. We used the PubMed/Medline and Embase databases to search for studies reporting IL17 polymorphisms in patients with asthma and healthy controls. Meta-analyses were conducted to determine the associations between IL17A rs8193036 (-737C/T), rs2275913 (-197G/A), rs3819024 (A/G), rs3748067 (C/T), and rs4711998 (A/G) and IL17F rs763780 (7488A/G), rs2397084 (T/C), rs1889570 (C/T), rs11465553 (G/A), and rs1266828 (T/C) polymorphisms and asthma susceptibility. A total of 20 studies were included in this meta-analysis. Our results revealed the IL17A rs8193036 CC genotype was associated with asthma susceptibility (odds ratio [OR] = 1.490, 95% confidence interval [CI] = 1.027-2.161, p = .036). However, stratification by ethnicity indicated no association between this polymorphism and asthma in European and Asian subjects. Furthermore, no association was found between this polymorphism and asthma using the allele contrast, dominant or homozygous contrast models. No evidence of an association was found between any of the other IL17A and IL17F polymorphisms and asthma susceptibility in this meta-analysis. This meta-analysis showed that, among the studied polymorphisms, only the CC genotype of IL17A rs8193036 is associated with asthma susceptibility.

Baricitinib for the treatment of intestinal Behçet's disease: A pilot study

OBJECTIVES

The pilot study aims to explore the efficacy and safety of baricitinib in treating refractory intestinal Behçet's disease (BD).

METHODS

We consecutively enrolled patients with refractory intestinal BD from October 2020 to September 2022. They were treated with baricitinib 2-4 mg daily, with background glucocorticoids and immunosuppressants. Efficacy assessment included the global gastrointestinal symptom scores, the endoscopy scores, the Disease activity index for intestinal Behçet's disease (DAIBD), and the inflammatory parameters. Side effects were recorded.

RESULTS

The thirteen patients (six males and seven females) had a median follow-up of eleven months, 76.92% (10/13) patients achieved complete remission of global gastrointestinal symptom scores, and 66.7% (6/9) had mucosal healing on endoscopy. The DAIBD scores decreased significantly, as well as the C-reactive protein level. Baricitinib showed a glucocorticoid-sparing effect, and the safety profile is favorable.

CONCLUSION

Baricitinib might be a potential choice in treating refractory intestinal BD.

Genetics in Behcet's Disease: An Update Review

Behcet's disease (BD) is one of the most vision-threatening clinical entities of uveitis. Although the etiopathogenesis of BD remains obscure, accumulating evidence has demonstrated that both genetic and environmental factors may contribute to the development of BD. Genome-wide association studies (GWAS) and candidate association studies have identified several genetic variants strongly associated with BD, including variants in human leukocyte antigen (HLA) -A02, -A03, -A24, -A26, -A31, -B15, -B27, -B35, -B49, -B51, -B57, -B58, -C0704, CIITA, ERAP1, MICA, IL1A-IL1B, IL10, IL12, IL23R, IL-23R/IL-12RB2, IL1RL1-IL18R1, STAT4, TFCP2L1, TRAF5, TNFAIP3, CCR1/CCR3, RIPK2, ADO-ZNF365-EGR2, KLRC4, LACC1, MEFV, IRF8, FUT2, CEBPB-PTPN1, ZMIZ1, RPS6KA4, IL10RA, SIPA1-FIBP-FOSL1, VAMP1, JRKL/CTCN5, IFNGR1 and miRNA-146a. Epigenetic modifications are also reported to play essential roles in the development of BD, including DNA methylation and histone modification. We review here the recent advances in the genetic and epigenetic factors associated with the BD pathogenesis.

Elevated X-Box Binding Protein1 Splicing and Interleukin-17A Expression Are Associated With Active Generalized Vitiligo in Gujarat Population

Vitiligo is an autoimmune skin disorder defined by the destruction of functional epidermal melanocytes. It is a multifactorial and polygenic disorder caused due to oxidative stress, endoplasmic reticulum (ER) stress, and autoimmunity, among other factors. In the present study, we aimed to investigate the association of X-box Binding Protein 1 (XBP1) and Interleukin-17A (IL-17A) polymorphisms and monitor their systemic as well as skin expression levels in vitiligo patients from Gujarat population in India. XBP1 rs2269577 G/C, IL17A rs2275913 G/A and IL17A rs8193036 C/T polymorphisms were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method in 312 controls and 276 vitiligo patients. Transcript levels of spliced (sXBP1), unspliced XBP1 (uXBP1) and IL17A from peripheral blood mononuclear cells (PBMCs) as well as spliced and unspliced XBP1 from skin samples were analyzed by qPCR. IL-17A protein levels in suction-induced blister fluid (SBF) from the skin of study subjects were estimated by ELISA. The results revealed that genotype (p=0.010) and allele (p=0.014) frequencies of XBP1 rs2269577 G/C polymorphism were significantly different, however, no significant difference was observed in frequencies of IL17A rs2275913 G/A and IL17A rs8193036 C/T polymorphisms in control and patient population. Gene expression analysis revealed that sXBP1 and IL17A levels were significantly higher in PBMCs of generalized (p=0.030 and p=0.039, respectively) and active (p=0.024 and p=0.017, respectively) vitiligo patients. Moreover, we observed a significantly elevated sXBP1 expression (p=0.037) as well as IL-17A protein levels (p=0.009) in perilesional skin of vitiligo patients as compared to controls. Overall, these findings suggest XBP1 and IL17A play an important role in vitiligo and further substantiate the involvement of ER stress in exacerbating immune-mediated vitiligo pathogenesis.

Epidemiologic and Etiological Features of Korean Patients With Behçet's Disease

Behçet's disease (BD) is a multisystem disease in which environmental factors provoke an adverse immune response in patients with genetic susceptibility towards BD, subsequently leading to a cascade of dysregulated inflammation throughout the body. It is particularly prevalent in regions spanning the ancient Silk Road, including Korea, where the first known case of BD was reported in 1961. We summarize the history, epidemiology, and clinical presentation of BD in Korea, highlighting the clinical tendencies that are particularly seen in the Korean BD population as compared to European populations. Analysis of epidemiologic trends over the past three decades in Korea shows a decreasing prevalence of complete BD and a higher prevalence of intestinal BD. We also discuss the ever-evolving understanding of the pathogenesis of BD, noting the complex interplay among genetics, environment, and immunology. The HLA-B51 allele is the most significant known genetic risk factor in developing BD. We also discuss more recently studied associations between BD and immune factors such as IL-10, IL-23R-IL-12RB2, IL-1A-IL-1B, CCR1, ERAP1, and the GIMAP cluster, the last of which has been found to have an association with BD specifically in Korea. Environmental factors such as pollution and microbials are often the inciting event in developing BD, as they trigger an imbalanced immune response in genetically susceptible individuals, one that has been often found to exhibit an aberrant Th1/Th17 response. There would be value to further studying the pathogenesis and clinical characteristics of Korean BD.

Genetics of Behçet's Disease: Functional Genetic Analysis and Estimating Disease Heritability

Behçet's disease is a chronic multisystemic inflammatory disorder characterized by recurrent oral and genital ulcers. Although its etiology remains unclear, it is thought that both genetic and environmental factors contribute to the onset and progression of Behçet's disease. Here, we provide an updated view of the genetic landscape and architecture of Behçet's disease. Large-scale genetic studies performed to date revealed 21 genetic susceptibility loci associated with the disease at a GWAS level of significance (p-value = 5 × 10⁻⁸). We performed epigenetic pattern enrichment analysis in Behçet's disease associated loci, providing new insights into the molecular mechanisms underlying its pathophysiology. Our data suggest the crucial involvement of several immune cell types, including natural killer cells, monocytes, and B cells in the pathogenesis of the disease. Pathway enrichment analysis identified important biological processes involved. Using large-scale genetic data available from ~200 immune-related loci (Immunochip), we estimate Behçet's disease heritability to be at least 16%. We further used the same approach to estimate the heritability explained by the known Behçet's disease-associated loci, suggesting that they explain ~ 60% of the genetic component underlying Behçet's disease. These results indicate a significant role of non-genetic factors in causing Behçet's disease and that additional genetic variation influencing the risk of Behçet's disease remains to be identified. Finally, we calculated a cumulative genetic risk score across populations reinforcing the link between geographic variations in disease prevalence with its genetic component.

Interleukin 17A deficiency alleviates fluoride-induced testicular injury by inhibiting the immune response and apoptosis

The reproductive toxicity of fluoride (F) has been verified by various epidemiological and experimental studies. Our previous work suggested that the interleukin 17A (IL-17A) is involved in the testicular damage induced by excessive F exposure. In this study, we further investigated the role of IL-17A in F-induced testicular injury. Wild type (WT) and IL-17A knockout (IL-17A^-/-) mice were exposed to 0, 25, 50, or 100 mg/L sodium fluoride (NaF) for 90 days. We found that exposure to excessive F levels caused testicular damage, decreased semen quality, negatively affected testicular morphology, and increased the inflammatory response. Specifically, excessive F intake increased the expression levels of IL-17A in the testis and increased the protein levels of Act1, NF-κB, IL-17R, C/EBP-α, and TRAF6 in the IL-17A signaling pathway. The increase in IL-17A expression corresponded to increases expression of IL-17R, IL-6, IL-23, IL-1β, TGF-β and TNF-α as assessed by RT-PCR and ELISA assays. Remarkably, IL-17A knockout in mice ameliorated the effects of F on testicular damage, semen quality, testicular morphology, and the immune response. Additionally, we found the in vitro exposure of Leydig cells to NaF and recombinant IL-17A led to abnormal apoptosis and a decrease in testosterone secretion. Our findings prove that IL-17A plays a key role in the exacerbation of testicular injuries in F-exposed mice, and that IL-17A deficiency can alleviate F-induced injury by inhibiting the immune response and apoptosis in the testis. These data suggest that targeting IL-17A may be a useful therapeutic strategy for treating F-mediated toxicity in the testis.

Advances in Management of Intestinal Behçet's Disease: A Perspective From Gastroenterologists

Intestinal Behçet's disease (intestinal BD) is a rare chronic inflammatory disorder of the intestine that is characterized by recurrent intestinal manifestations with other systemic features of BD. Intestinal BD is diagnosed when a typically shaped ulcer is observed in the gastrointestinal tract, and the clinical findings meet the diagnostic criteria for BD. Owing to the small number of patients, intestinal BD is easily underestimated. On the other hand, but it often requires surgical treatment because of severe complications, including intestinal perforations or massive bleeding. The same treatment strategies used for inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis, are used for intestinal BD. 5-Aminosalicylic acids, corticosteroids, and immunomodulators are considered conventional therapies, but a considerable number of patients eventually become unresponsive to these pharmaceutical treatments. Recently, biologic agents, such as anti-tumor necrosis factor-alpha inhibitors, have also been suggested as a new treatment option for intestinal BD. This article reviews the pathogenesis and diagnosis of intestinal BD and the current treatment strategies that are expected to be useful for rheumatologic specialists.

Immune Response-Related Genes - STAT4, IL8RA and CCR7 Polymorphisms in Lung Cancer: A Case-Control Study in China

Purpose

This study aimed to evaluate the associations between immune response-related genes – STAT4, IL8RA and CCR7 polymorphisms and risk of lung cancer.

Methods

Seven polymorphisms of STAT4, IL8RA and CCR7 were genotyped in 350 cases and 350 controls using a MassARRAY platform.

Results

The STAT4 rs1400656-G and rs7574865-T alleles may decrease the susceptibility to lung cancer (p_rs1400656= 0.020; p_rs7574865= 0.014); while IL8RA rs1008562-C and CCR7 rs3136685-T alleles may increase the risk of disease (p_rs1008562< 0.001; p_rs3136685= 0.018). The STAT4 rs1400656-GA and rs7574865-GT genotypes were determined as protective genotypes against lung cancer risk (p_rs1400656= 0.048; p_rs7574865= 0.042). However, IL8RA rs1008562-CG/GG and CCR7 rs3136685-TT genotypes were significantly associated with an elevated risk of disease (p_rs1008562< 0.0001; p_rs3136685= 0.020). Genetic model analysis revealed that STAT4 rs1400656 and rs7574865 were relate to a declining risk of disease under dominant and log-additive models (rs1400656: p_dominant = 0.014, p_log-additive= 0.016; rs7574865: p_dominant = 0.013, p_log-additive= 0.013). In contrast, IL8RA rs1008562 exhibited a strong correlation with an elevated risk of lung cancer under all three models (p_dominant < 0.0001, p_recessive = 0.011, p_log-additive< 0.0001). Moreover, CCR7 rs3136685 was correlated with an increased risk of disease under recessive and log-additive models (p_recessive = 0.007, p_log-additive= 0.019); and CCR7 rs17708087 was also identified as a risk factor in the dominant model (p = 0.038).

Conclusion

These results widen the scope of knowledge about the association between STAT4, IL8RA and CCR7 polymorphisms and risk of lung cancer.

Activation of the interleukin-23/interleukin-17 signalling pathway in autoinflammatory and autoimmune uveitis

Uveitis is a group of diseases characterized by intraocular inflammation, of which some are driven by autoinflammatory or autoimmune responses, such as Vogt-Koyanagi-Harada disease, Behçet's disease, uveitis associated with spondyloarthritis, ocular sarcoidosis, sympathetic ophthalmia and birdshot chorioretinopathy. These entities have various clinical forms, but genetic and biomarker data suggest that they share a common molecular basis, activation of the Interleukin (IL)-23/IL-17 pathway. Multiple factors including genetic predisposition, various cytokine imbalances, infectious agents and gut alterations are found to trigger an aberrant response of this pathway. The enhanced activity of the IL-23/IL-17 pathway is committed to the expansion and pathogenicity of Th17 cells. Evidence from animal models demonstrates that the development of pathogenic Th17 cells is responsible for the induction of experimental autoimmune uveitis. Further findings indicate that retinal pigment epithelium (RPE) cells may be a target of IL-17. IL-17 triggers downstream inflammatory cascades and causes dysfunction of RPE cells, which may affect retinal barrier function and thereby promote intraocular inflammation. Currently, several emerging drugs blocking the IL-23/IL-17 pathway have been assessed for the treatment of uveitis in pilot studies. The purpose of this is to summarize updated biological knowledge and preliminary clinical data, providing the rationale for further development and evaluation of novel drugs targeting the IL-23/IL-17 pathway in autoinflammatory and autoimmune uveitis. Future studies may focus on translational medicine targeting the IL-23/IL-17 pathway for the improvement of diagnosis and treatment of uveitis. In conclusion, activation of the IL-23/IL-17 pathway is a critical biological event and can be an important target for the treatment of autoinflammatory and autoimmune uveitis.

Associations of Mitochondrial Deoxyribonucleic Acid Polymorphisms With Behçet's Disease in the Korean Population

Objectives

This study aims to examine the possible associations of mitochondrial single nucleotide polymorphisms (SNPs) and Behçet's disease (BD) in a larger patient group.

Patients and methods

Whole blood or buffy coat was collected from 98 BD patients (31 males, 67 females; mean age 48±2.8 years; range 20 to 60 years) from four university hospitals located in the Chung-Cheong district of the Republic of Korea, and 196 age- and sex-matched healthy controls (HCs) (62 males, 134 females; mean age 46.91±12.90 years; range 20 to 68 years) from Konyang University Hospital. Twenty targeted mitochondrial deoxyribonucleic acids (DNAs) were genotyped and compared using the revised Cambridge Reference Sequence. Chi square and Fisher's exact tests were used to analyze association of mitochondrial DNA SNPs with BD susceptibility and its clinical characteristics.

Results

There were no differences for m.248A>G, m.304C>A, m.709G>A, m.3010G>A, m.3970C>T, m.4883C>T, m.5178C>A, m.6392T>C, m.6962G>A, m.10310G>A, m.10609T>C, m.12406G>A, m.12882C>T, m.13928G>C, m.14668C>T, m.16129G>A, and m16304T> between patient and HC groups. However, m.16182A>C and m.16183A>C were more frequently observed in the patient group than the HC group (22 [22.4%] vs. 24 [12.2%], p=0.061 and 32 [32.7%] vs. 42 [21.4%], p=0.092) but without statistical significance. m.4883C>T and m.5178C>A were associated with posterior location of oral ulcers (p=0.025 for each) and m.16183A>C was associated with deep oral ulcers (p=0.001), while m.16189T>C was associated with deep oral ulcers and thrombosis (p=0.042, 0.048, respectively).

Conclusion

m.16182A>C and m.16183A>C may be associated with BD in the Korean population.

Proteomics-based functional studies reveal that galectin-3 plays a protective role in the pathogenesis of intestinal Behçet's disease

The pathogenesis of intestinal Behçet’s disease (BD) remains poorly understood. Therefore, we aimed to discover and validate biomarkers using proteomics analysis and subsequent functional studies. After two-dimensional electrophoresis, candidate proteins were identified using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS). We validated these results by evaluating the protein levels and their functions in vitro using HT-29 colorectal cancer cells, colon tissues from patients and mice, and murine bone marrow derived macrophages (BMDMs). Of the 30 proteins differentially expressed in intestinal BD tissues, we identified seven using MALDI-TOF/TOF MS. Focusing on galectin-3, we found that TGF-B and IL-10 expression was significantly lower in shLGALS3-transfected cells. Expression of GRP78 and XBP1s and apoptosis rates were all higher in shLGALS3-transfected cells upon the induction of endoplasmic reticulum stress. In response to lipopolysaccharide stimulation, microtubule-associated protein 1 light chain 3B accumulated and lysosomes decreased in these cells. Finally, Salmonella typhimurium infection induced caspase-1 activation and increased IL-1β production, which facilitated activation of the NLRC4 inflammasome, in Lgals3^−/− murine BMDMs compared to wild type BMDMs. Our data suggest that galectin-3 may play a protective role in the pathogenesis of intestinal BD via modulation of ER stress, autophagy, and inflammasome activation.

Behçet's disease: An immunogenetic perspective

Behçet's disease (BD) is a chronic and rare multisystemic disorder defined by autoimmunity and inflammatory characteristics, manifested by ocular lesions, recurrent genital and oral ulcers, skin symptoms and arthritis as well as neurological, intestinal, and vascular involvement. Despite the unknown cause of BD, there is some strong documentation for immunological, genetic, environmental, and infectious factors playing a role in the pathogenesis of BD. While the nature of the genetic variants remains unidentified, many genetic risk factors are considered to contribute to BD susceptibility. Along with human leukocyte antigen gene encoding B*51 (HLA-B*51) and areas including the major histocompatibility complex class I, genome-wide association studies have recognized numerous other BD susceptibility genes including those encoding interleukin (IL)-10, IL-12 receptor β 2 (IL-12RB2), IL-23 receptor (IL-23R), C-C chemokine receptor 1 gene, signal transducer and activator of transcription 4 (STAT4), endoplasmic reticulum aminopeptidase (ERAP1), and genes encoding killer cell lectin-like receptor family members (KLRC4-KLRK1). It is believed that BD could be considered as a disorder lying in between autoimmune and autoinflammatory syndromes. The positive responses to classical immunosuppressive agents like azathioprine and cyclosporine and involvement of autoantigens in the initiation of the disorder are the main BD features that reflect the autoimmune nature of the disorder. In this review, we address recent findings on the role of common cytokines, antibodies and immunogenetic factors in BD.

Immunopathogenesis of Behçet Disease

BACKGROUND

Behçet's Disease (BD, OMIM 109650) is a chronic relapsing inflammatory disease of unknown etiology with unpredictable exacerbations and remissions. First described in 1937 by the Turkish dermatologist HulusiBehçet, as a trisympton complex (oral and genital ulcers and uveitis), it is now recognized as a multisystemic disease. The syndrome can manifest in diverse ways and can involve nearly every organ system. Several studies have implicated T cells and monocytes in the pathogenesis of BD especially when these cells are stimulated by heat shock proteins and streptococcal antigen. This article presents a review of the relevant published literature about the immunopathogenesis of BD.

RESULT

The authors used MeSH terms "Behçet's disease" with "pathophysiology," "pathogenesis," "genetic", "epigenetic", "immunogenetic" or "immune response" to search the PubMed database. All the relevant studies identified were included.

Methylation status of interleukin-6 gene promoter in patients with Behçet's disease

BACKGROUND

IL-6 mRNA expression is significantly high in many autoimmune diseases such as Behçet's disease; this is often related with more aggressive phenotypes. Nevertheless, the essential molecular process for its high expression has not been completely realized. The aim of this study was undertaken to estimate the gene copy number variation and promoter methylation to IL-6's high expression.

METHODS

This study was performed on 51 patients and 61 healthy controls. Initially, DNA and RNA were extracted from all specimens. Promoter methylation levels of IL-6 were evaluated by MeDIP-qPCR technique. Also, IL-6 gene expression was measured by Real-time PCR. After that, we evaluated the relationship between gene expression and methylation, as well as their relationship with clinical specification.

RESULTS

As we expected, the expression level of IL-6 gene increased significantly in the patient group compared to the healthy subjects. Also, the relative promoter methylation level of the IL-6 mRNA was significantly lower in patient group compared to healthy group (p<0.001).

DISCUSSION

We disclosed that the promoter hypomethylation may be considered as one of the main defects for IL-6 mRNA high expression in patients with Behçet's disease.

Gastrointestinal Involvement in Behçet Disease

Behçet disease (BD) is a variable vessel vasculitis that can involve several organs and systems. Gastrointestinal (GI) involvement has an acute exacerbating course with ulcers, most commonly in the ileocolonic area. These ulcers can be large and deep, causing perforation and massive bleeding. This article highlights the current knowledge on the epidemiology, clinical findings, diagnosis, and management of GI involvement of BD, with emphasis on recent findings.

IL-23R and IL-17A polymorphisms correlate with susceptibility of ankylosing spondylitis in a Southwest Chinese population

The association between the IL-23R and IL-17A polymorphisms and ankylosing spondylitis (AS) in the Southwest Chinese Population is still unclear. The purpose of this study is to detect the association between IL-23R and IL-17A polymorphisms and AS. A case-control study consisting of 486 AS patients and 480 healthy controls was performed. We used the high-resolution melting methods (HRM) to genotype five selected single nucleotide polymorphisms (SNPs), rs6693831, rs7517847, rs1884444, rs10889677 in the IL-23R gene and rs2275913 in the IL-17A gene. Meanwhile, the laboratory indexes were recorded. In this study, patients with genotype CC (p = 8.574E-8) and allele C (p = 3.206E-31) on SNP rs6693831 (IL-23R) showed decreased risk of AS. The genotype TT (p = 4.551E-6) and allele T (p = 0.02) on SNP rs1884444 (IL-23R) showed significant lower risk of AS. Individuals carrying the allele A of rs2275913 showed higher morbidity of AS (p = 0.04). We first detected that rs6693831 and rs1884444 in IL-23R gene and rs2275913 in IL-17A gene have genetic association with AS.

The Role of Th17 Cells in the Pathogenesis of Behcet's Disease

Behcet's disease (BD) is a polysymptomatic and recurrent systemic vasculitis with a chronic course and unknown cause. The pathogenesis of BD has not been fully elucidated; however, BD has been considered to be a typical Th1-mediated inflammatory disease, characterized by elevated levels of Th1 cytokines such as IFN-γ, IL-2, and TNF-α. Recently, some studies reported that Th17-associated cytokines were increased in BD; thus, Th17 cells and the IL17/IL23 pathway may play important roles in the pathogenesis of BD. In this chapter, we focus on the pathogenic role of Th17 cells in BD.

Behçet disease: New aspects

Behçet disease is currently considered an "autoinflammatory disease" triggered by infection and environmental factors in genetically predisposed individuals. Although the disease is characterized by recurrent oral and genital aphthous ulcers and ocular involvement, it can affect multiple organ systems. Complex aphthosis is characterized by recurrent oral and/or genital aphthous ulcers. It is important to evaluate the patient with complex aphthosis for Behçet disease and related systemic disorders. We discuss the etiopathogenesis, clinical features, diagnostic criteria, and treatment approaches for complex aphthosis and Behçet disease in light of the current literature.

Association of cytokine gene polymorphisms (IL‑6, IL‑12B, IL‑18) with Behcet's disease : A meta-analysis

PURPOSE

This study aims to investigate the association of cytokine gene polymorphisms with the risk of Behcet's disease (BD) via comprehensive meta-analysis.

METHODS

The Embase and PubMed databases covering the period from the earliest possible year to May 2015 were searched. A total of 13 eligible articles including 2,065 BD patients and 1,559 controls were recruited. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of the associations. Potential publication bias was evaluated using Egger's linear regression test.

RESULTS

Meta-analysis indicated associations between IL‑6 rs1800795, IL‑12B rs3212227, and IL‑18 rs1946518 in all study subjects: IL‑18 rs1946518 in the dominant model (IL‑18 rs1946518: OR = 0.48, 95 % CI: 0.34-0.70, P = 0.000) and the homozygote model (IL‑18 rs1946518: OR = 0.40, 95 % CI: 0.25-0.65, P = 0.000); and IL‑6 rs1800795 and IL‑12B rs3212227 in the dominant model (IL‑6 rs1800795: OR = 0.53, 95 % CI: 0.39-0.72, P = 0.000; IL‑12B rs3212227: OR = 1.26, 95 % CI: 1.06-1.48, P = 0.007; IL‑18 rs1946518: OR = 0.46, 95 % CI: 0.33-0.65, P = 0.000). No significant evidence for associations of IL‑18 rs187238 polymorphisms with BD susceptibility was detected.

CONCLUSION

In summary, this meta-analysis finds that IL‑6 rs1800795 and IL‑18 rs1946518 polymorphisms decrease the risk of BD. However, IL‑12B rs3212227 increases BD susceptibility. Further large-scale investigation of this association is necessary.

Effect of donor STAT4 polymorphism rs7574865 on clinical outcomes of pediatric acute leukemia patients after hematopoietic stem cell transplant

STAT4 polymorphism, rs7574865 is linked to various autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. Its T minor allele is associated with higher STAT4 mRNA and protein expression, indicating a stronger skewed immune response than the norm. Although widely studied in autoimmune disease patients and the general population, its effect on immunocompromised subjects is still unknown. Especially in situations, i.e. post-hematopoietic stem cell transplantation (post-HSCT), where control of the immune response is crucial. Hence, this study investigates if the presence of the T minor allele in donors would affect immunological response and clinical outcomes post-HSCT. Samples from 161 pediatric patients who underwent allogeneic HSCT for acute leukemia and showed complete chimerism by donor cells were obtained. Six clinical outcomes were investigated; hepatic veno-occlusive disease, acute graft-vs-host disease, chronic graft-vs-host disease, cytomegalovirus (CMV) infection, relapse and overall survival. The TT genotype was found to be significant in the occurrence of CMV infection (P=0.049), showing higher incidence of CMV infection compared to the others. Multivariate analysis confirmed that association of the TT genotype is independent from other variables in CMV infection occurrence (P=0.010). This is the first study on STAT4 polymorphism rs7574865 in allogeneic HSCT as well as immunocompromised patients. As the TT genotype is associated with autoimmune diseases, our results seem at a paradox with current evidence hinting at a different role of STAT4 in normal circumstances versus immunocompromised patients. Further investigation is needed to elicit the reason behind this and discover novel applications for better post-transplant outcomes.

Cytotoxic Th1 and Th17 cells infiltrate the intestinal mucosa of Behcet patients and exhibit high levels of TNF-α in early phases of the disease

BACKGROUND

Gastrointestinal involvement is one of the most serious in Behçet disease, potentially leading to severe complications. Aim of this study was to investigate at mucosal level the T-cell responses in Behçet patients with early intestinal involvement.

METHODS

We isolated T cells from intestinal mucosa of 8 patients with intestinal symptoms started within 6 months. T lymphocytes were cloned and analyzed for surface phenotype and cytokines production.

RESULTS

We obtained 382 T-cell clones: 324 were CD4+ and 58 were CD8+. Within the 324 CD4+ clones, 195 were able to secrete IFN-γ and TNF-α, but not IL-4, nor IL-17 thus showing a polarized Th1 profile, whereas CD4 clones producing both IFN-γ and IL-17 (Th1/Th17 profile) were 79. Likewise, the number of CD8 clones producing type 1 cytokines was higher than those of CD8 clones producing both type 1 and 2 cytokines.Almost all intestinal-derived T-cell clones expressed perforin-mediated cytotoxicity and Fas-Fas Ligand-mediated pro-apoptotic activity.

CONCLUSIONS

Our results indicate that in the early stages of the disease, both Th1 and Th17 cells drive inflammation leading to mucosal damage via abnormal and long-lasting cytokines production as well as via both perforin- and Fas-Fas ligand-mediated cytotoxicity. Finally, all the T cells at mucosal level were able to produce large amount of TNF-α, suggesting that its production is a property of intestinal T cells of patients with early active intestinal disease. These results support the therapy with anti-TNF-α agents and suggest the use of anti-IL-17 monoclonal antibodies in Behçet patients with early intestinal involvement.

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.

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.

The relevance of miRNA-21 in HSV-induced inflammation in a mouse model

The purpose of this study was to clarify the correlation between microRNA-21 (miR-21) expression and inflammation in a herpes simplex virus (HSV)-induced Behçet’s Disease (BD) mouse model. miR-21 was compared between BD patients and healthy controls in peripheral blood mononuclear cells (PBMC). For miR-21 inhibition, miR-21 antagomir was applied to BD mice. The change of symptoms was monitored. The levels of cytokines and related molecules were determined by ELISA and real time qPCR. Treatment with colchicine or pentoxifylline down-regulated the level of miR-21 with improved symptoms in mice. miR-21 inhibition was accompanied by down-regulated serum levels of IL-17 and IL-6. The expression levels of PDCD4, RhoB, PD-1, IL-12p35, and toll-like receptor-4 were also regulated by miR-21 inhibition. miR-21 was correlated with HSV-induced BD-like inflammation in mice and BD patients. The expression of miR-21 was regulated by antagomir in mice.

Specific association of IL17A genetic variants with panuveitis

BACKGROUND/AIMS

A pathogenic role of Th17 cells in uveitis has become clear in recent years. Therefore, in the present study, we aimed to evaluate the possible influence of the IL17A locus on susceptibility to non-anterior uveitis and its main clinical subgroups.

METHODS

Five IL17A polymorphisms (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909), selected by tagging, were genotyped using TaqMan assays in 353 Spanish patients with non-anterior uveitis and 1851 ethnically matched controls.

RESULTS

The case/control analysis yielded a consistent association between two of the analysed genetic variants, rs8193036 and rs2275913, and the presence of panuveitis under a dominant model (pFDR=2.86E-03, OR=2.26, 95% CI 1.42 to 3.59 and pFDR=0.033, OR=1.83, 95% CI 1.13 to 2.97, respectively). Subsequently, a specific association of both polymorphisms with the diffuse form of the disease was evident in the subphenotype analysis when considering this same genetic model (panuveitis vs posterior and intermediate uveitis: rs8193036, p=0.020; rs2275913, p=0.038). Independent effects of rs8193036 and rs2275913 were observed by conditional regression analysis.

CONCLUSIONS

Polymorphisms within the IL17A locus show a novel association with panuveitis. Our data agree with the elevated levels of this cytokine that are found in patients with uveitis, supporting a crucial role of Th17 cells in this pathology.

SUBTITLE

Our results clearly evidenced the role of IL17A as a novel genetic risk factor for panuveitis, thus suggesting the implication of Th17 cells in the extensive inflammation of the uveal tract that occurs in this subtype of uveitis.

Serum Cytokine Levels in Behçet's Disease

BACKGROUND

The aim of this study is to investigate and compare the serum levels of various cytokines in patients with Behçet's Disease and healthy controls.

METHODS

Thirty-five patients with Behçet's disease and 29 age and sex-matched healthy controls were included in the study. The patients were separated into groups with active and inactive disease. Serum IL-2, IL-6, IL-8, IL-10, IL-17A, and IFN-γ levels were determined using the enzyme-linked immunosorbent assay method. Cytokine levels of the two patient groups and healthy controls were compared using SPSS 15.0.

RESULTS

Ten patients with active disease and 25 patients with inactive disease were present. Serum IL-8 levels of active BD patients were higher compared to inactive patients (P = 0.048) and healthy controls (P = 0.02). IL-8 levels were correlated with the duration of symptoms (r = 0.490, P = 0.003) and time passed since diagnosis (r = 0.579, P ˂ 0.001).

CONCLUSION

Behçet's disease involves complex interactions of cells of the immune system, mainly T lymphocytes and neutrophils. Further studies on the cytokine profile in Behçet's disease will aid in elucidation of its pathogenesis.

Association between STAT4 gene polymorphisms and autoimmune thyroid diseases in a Chinese population

The STAT4 gene encodes a transcriptional factor that transmits signals induced by several key cytokines which play important roles in the development of autoimmune diseases. The aim of this study was to explore the association of STAT4 polymorphism with Graves’ disease (GD) and Hashimoto’s thyroiditis (HT). A total of 1048 autoimmune thyroid diseases (AITDs) patients (693 with GD and 355 with HT) and 909 age- and gender-matched controls were examined. STAT4 polymorphisms (rs7574865/rs10181656/rs7572482) were genotyped by multiplex polymerase chain reaction (PCR) and ligase detection reaction (LDR). The results indicated that the frequencies of rs7574865 genotypes in patients with GD differed significantly from the controls (p = 0.028), the T allele frequency of GD patients was also significantly higher than the controls (p = 0.020). The genotypes of rs10181656 differed significantly in GD patients from controls (p = 0.012); G allele frequencies were significantly higher in AITD patients than the controls (p = 0.014 and 0.031, respectively). The frequencies of haplotype GC with GD and HT patients were significantly lower than their controls (p = 0.015 and 0.030, respectively). In contrast, the frequencies of haplotype TG with GD and HT patients were significantly higher than their controls (p = 0.016 and 0.048, respectively). These findings strongly suggest that STAT4 rs7574865/rs10181656 polymorphisms increase the risk of AITD in a Chinese population.

Association of a TNIP1 polymorphism with Vogt-Koyanagi-Harada syndrome but not with ocular Behcet's disease in Han Chinese

Objectives

The aim of the study was to investigate the association of TNFα-induced protein 3 interacting with protein 1 (TNIP1) gene polymorphisms with Vogt–Koyanagi–Harada (VKH) syndrome and Behcet’s disease (BD) in a Han Chinese population.

Methods

A total of 656 BD patients, 961 VKH syndrome patients and 1534 healthy controls were included in this two-stage case control study. Seven SNPs, including rs17728338, rs7708392, rs10036748, rs3762999, rs999556, rs4958881 and rs3792783, belonging to TNIP1 were genotyped and analyzed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The data were analyzed by using the χ2 or Fisher's exact test and corrected for multiple comparisons by the Bonferroni method.

Results

A significantly increased frequency of the GG genotype and a decreased frequency of the AG genotype of rs17728338 were found in VKH patients (Pc = 0.038 OR = 1.934, 95% CI  = 1.438∼2.601). No significant difference was noted in allele or genotype frequencies of rs7708392, rs10036748, rs3762999, rs999556, rs4958881 and rs3792783, between VKH patients and healthy controls (Pc>0.05). No significant difference was noted in allele or genotype frequencies of the tested 7 SNPs between BD patients and healthy controls. Analysis of extraocular clinical findings, did not reveal an association of the TNIP1 gene polymorphisms with BD or VKH syndrome subgroups.

Conclusion

A TNIP1 polymorphism may be a risk factor for VKH syndrome in Han Chinese.

Significant association between interleukin-17A polymorphism and colorectal cancer

Interleukin (IL) 17A is an inflammatory cytokine expressed by Th 17 cells and plays a role in tissue inflammation by inducing release of proinflammatory and neutrophil-mobilizing cytokines. We have investigated the association between colorectal cancer and polymorphisms of IL17A (rs2275913. G197A). The study was performed in 241 subjects (102 with colorectal cancer and 139 healthy controls). Genotypes were determined by fluorescent-based restriction fragment length polymorphism method. The association between the molecular features at the gene in relation to tumor and patient clinical characteristics was analyzed. There was a significant difference between the genotype frequencies of IL17A G197A of control subjects (GG 68.34 % and GA + AA 31.65 %) and patients with colorectal cancer (GG 47.05 % and GA + AA 52.94 %) (p = 0.001 with odds ratio (OR) 2.45 (1.43-4.11)). IL17A G197A polymorphism is particularly associated with colon cancer. Indeed, the IL17A GG genotype could be considered as a protective factor against colon cancer (p = 0.00001) with OR 3.77 (2.04-6.99). We have noted a significant association of IL17A G197A polymorphism not only with tumor localization (p = 0.003) but also with tumor differentiation (p = 0.0005) in CRC patients. We have also showed a significant association of G197A variant with an increased risk of advanced stage (p = 0.005). Our result suggests that the A allele of IL17A gene is involved in susceptibility to colorectal cancer and is associated with clinical features as tumor location, tumor differentiation, and TNM stage. IL17A polymorphism may serve as biomarker of disease location and progression.

Skewed Helper T-Cell Responses to IL-12 Family Cytokines Produced by Antigen-Presenting Cells and the Genetic Background in Behcet's Disease

Behcet's disease (BD) is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. Recently, we found that Th17 cells, a new helper T (Th) cell subset, were increased in patients with BD, and both Th type 1 (Th1) and Th17 cell differentiation signaling pathways were overactivated. Several researches revealed that genetic polymorphisms in Th1/Th17 cell differentiation signaling pathways were associated with the onset of BD. Here, we summarize current findings on the Th cell subsets, their contribution to the pathogenesis of BD and the genetic backgrounds, especially in view of IL-12 family cytokine production and pattern recognition receptors of macrophages/monocytes.

Association Analysis of IL10, TNF-α, and IL23R-IL12RB2 SNPs with Behçet's Disease Risk in Western Algeria

Objective: We have conducted the first study of the association of interleukin (IL)-10, tumor necrosis factor alpha (TNF-α), and IL23R-IL12RB2 region single nucleotide polymorphisms (SNPs) with Behçet’s disease (BD) in Western Algeria.

Methods: A total of 51 BD patients and 96 unrelated controls from West region of Algeria were genotyped by direct sequencing for 11 SNPs including 2 SNPs from the IL10 promoter [c.-819T > C (rs1800871), c.-592A > C (rs1800872)], 6 SNPs from the TNF-α promoter [c.-1211T > C (rs1799964), c.-1043C > A (rs1800630), c.-1037C > T (rs1799724), c.-556G > A (rs1800750), c.-488G > A (rs1800629), and c.-418G > A (rs361525)], and 3 SNPs from the IL23R-IL12RB2 region [g.67747415A > C (rs12119179), g.67740092G > A (rs11209032), and g.67760140T > C (rs924080)].

Results: The minor alleles c.-819T and c.-592A were significantly associated with BD [odds ratio (OR) = 2.18; 95% confidence interval (CI) 1.28–3.73, p = 0.003]; whereas, there was weaker association between TNF-α promoter SNPs or IL23R-IL12RB2 region and disease risk.

Conclusion: Unlike the TNF-α and the IL23R-IL12RB2 region SNPs, the two IL10 SNPs were strongly associated with BD. The -819T, and -592A alleles and the -819TT, -819CT, and -592AA and -592CA genotypes seem to be highly involved in the risk of developing of BD in the population of Western Algeria.

A genome-wide association study identifies risk loci to equine recurrent uveitis in German warmblood horses

Equine recurrent uveitis (ERU) is a common eye disease affecting up to 3-15% of the horse population. A genome-wide association study (GWAS) using the Illumina equine SNP50 bead chip was performed to identify loci conferring risk to ERU. The sample included a total of 144 German warmblood horses. A GWAS showed a significant single nucleotide polymorphism (SNP) on horse chromosome (ECA) 20 at 49.3 Mb, with IL-17A and IL-17F being the closest genes. This locus explained a fraction of 23% of the phenotypic variance for ERU. A GWAS taking into account the severity of ERU, revealed a SNP on ECA18 nearby to the crystalline gene cluster CRYGA-CRYGF. For both genomic regions on ECA18 and 20, significantly associated haplotypes containing the genome-wide significant SNPs could be demonstrated. In conclusion, our results are indicative for a genetic component regulating the possible critical role of IL-17A and IL-17F in the pathogenesis of ERU. The associated SNP on ECA18 may be indicative for cataract formation in the course of ERU.

Potentially functional polymorphism in IL-23 receptor and risk of acute myeloid leukemia in a Chinese population

The interleukin-23 (IL-23) and its receptor (IL-23R) mediate the direct antitumor activities in human hematologic malignancies including pediatric acute leukemia. Two potentially functional genetic variants (IL-23R rs1884444 T>G and rs6682925 T>C) have been found to contribute to solid cancer susceptibility. In this study, we conducted a case-control study including 545 acute myeloid leukemia (AML) patients and 1,146 cancer-free controls in a Chinese population to assess the association between these two SNPs and the risk of AML. We found that IL-23R rs1884444 TG/GG and rs6682925 TC/CC variant genotypes were associated with significantly increased risk of AML [rs1884444: adjusted odds ratio (OR) = 1.28, 95% confidence interval (CI) = 1.01–1.62; rs6682925: adjusted OR = 1.30, 95%CI = 1.01–1.67], compared to their corresponding wild-type homozygotes, respectively. These findings indicated that genetic variants in IL-23R may contribute to AML risk in our Chinese population.

Difference of interleukin-23 receptor gene haplotype variants in ulcerative colitis compared to Crohn's disease and psoriasis

OBJECTIVE

Polymorphisms of the interleukin-23 receptor (IL23R) gene have been found to play a role in the development of several autoimmune diseases. Our aim was to examine the possible effect of not only simple individual variants, but of haplotypes composed of them.

SUBJECTS

We analysed 263 patients with psoriasis, 199 patients with Crohn's disease (CD), 282 patients with ulcerative colitis (UC), and 253 controls for rs1884444, rs11805303, rs7517847, rs2201841, rs10889677 and rs11209032 variants.

METHODS

The genotypes were determined by using PCR/RFLP assay. Logistic regression analysis was used to compare the genotype distribution of the polymorphisms and haplotypes between the examined autoimmune diseases and healthy controls.

RESULTS

Rs1884444 was found to confer risk for UC and psoriasis, rs10889677 for CD and psoriasis, while rs2201841 and rs7517847 had effect only in CD. Using these SNPs we could study the susceptibility haplotype profiles in these diseases with special attention to UC. Eight different haplotypes could be differentiated. We found that the SNPs exert their susceptibility character in specific haplotype blocks, and the frequency of one haplotype differed significantly in UC compared with both other diseases and also with healthy controls. This haplotype conferred risk for UC, even while it had a somewhat lower frequency in the other diseases than in controls.

CONCLUSIONS

The data presented here serve as evidence for the need of haplotype analysis instead of just single standing SNP analysis when susceptibility is interpreted.

Genetics of inflammatory bowel diseases: a comparison between Western and Eastern perspectives

Inflammatory bowel disease (IBD) is a chronic relapsing intestinal inflammatory disorder with unidentified causes. Currently, studies indicate that IBD results from a complex interplay between various genetic and environmental factors that produce intestinal inflammation. However, these factors may differ for Asians and Caucasians. Thus, differences in epidemiology, genetic variants, and clinical phenotypes of IBD have been observed between the two populations. Understanding the discrepancies between data from populations with different genetic backgrounds and environmental factors may reveal fundamental aspects of IBD pathogenesis. Accordingly, this review will summarize the current knowledge of IBD genetics studied in Asian countries and compare it with that from Western countries, with special focus on innate bacterial sensing, autophagy, and the interleukin-23 receptor-T helper cell 17 pathway. The epigenetic nature of IBD pathogenesis as well as the pharmacogenetics related to the use of immunomodulators will also be briefly covered.

Association between polymorphisms in interleukin-17A and -17F genes and chronic periodontal disease

OBJECTIVE

Interleukin-17 (IL-17) is a cytokine that induces neutrophil recruitment and the release of inflammatory mediators in several inflammatory conditions; nevertheless, the involvement of IL-17 gene polymorphisms in chronic periodontitis (CP) has not been addressed yet. Our aim was to evaluate the association between periodontal status and the polymorphisms IL-17A G197A and IL-17F C7488T in subjects with CP along with their impact on levels of inflammatory mediators.

MATERIAL AND METHODS

Genomic DNA was obtained from 30 CP patients and 30 healthy controls (HCs). IL-17A G197A and IL-17F C7488T polymorphisms were determined using PCR-RFLP. Serum and periodontal tissues were collected and processed for ELISA, myeloperoxidase (MPO), and/or microscopic analysis.

RESULTS

The frequencies of genotypes in the CP group were significantly different from those of HC. Odds ratio indicated that increased risks for CP were associated with the -197A allele, not with the -7488T allele. In addition, the -197A allele was correlated with worse clinical parameters, higher MPO activity, and increased expression of inflammatory mediators (IL-17A and IL-8) than the other genotypes.

CONCLUSIONS

These results indicate that the IL-17A -197A allele is associated with increased risk for CP, likely because this genotype relates to the enhanced inflammation in periodontal tissues.

The oncoprotein HBXIP uses two pathways to up-regulate S100A4 in promotion of growth and migration of breast cancer cells

We have reported that hepatitis B X-interacting protein (HBXIP) promotes the proliferation and migration of breast cancer cells. However, the underlying mechanism is poorly understood. In this study, we report that HBXIP works in the event through up-regulating S100A4. We observed that HBXIP expression was positively correlated to that of S100A4 in 87 clinical breast cancer tissue samples. Then, we identified that HBXIP was able to up-regulate S100A4 expression in breast cancer cells. Notably, we observed the HBXIP nuclear localization, implying that HBXIP may be associated with the promoter of S100A4. Chromatin immunoprecipitation assay (ChIP) and electrophoretic mobility shift assay (EMSA) showed that HBXIP was able to bind to the nucleotides +200~+239 region of S100A4 promoter, containing two putative recognition motif of transcription factor STAT4 and GRβ. It suggests that HBXIP is able to activate S100A4 promoter via interacting with STAT4 in breast cancer cells, leading to the up-regulation of S100A4. In addition, we identified another pathway of S100A4 up-regulation mediated by HBXIP. We found that HBXIP activated the PTEN/PI3K/AKT signaling by inducing DNA methylation of PTEN, which subsequently boosted S100A4 expression. In function, we demonstrated that HBXIP enhanced the growth or migration of breast cancer cells through S100A4 in vivo and in vitro. Collectively, we conclude that HBXIP up-regulates S100A4 through activating S100A4 promoter involving STAT4 and inducing PTEN/PI3K/AKT signaling to promote growth and migration of breast cancer cells. Our finding provides new insight into the mechanism of HBXIP in promotion of the development of breast cancer.