Genetic variants in the JAK1 gene confer higher risk of Behcet's disease with ocular involvement in Han Chinese

OR11H1 Missense Variant Confers the Susceptibility to Vogt-Koyanagi-Harada Disease by Mediating Gadd45g Expression

Vogt-Koyanagi-Harada (VKH) disease is a severe autoimmune disease. Herein, whole-exome sequencing (WES) study are performed on 2,573 controls and 229 VKH patients with follow-up next-generation sequencing (NGS) in a collection of 2,380 controls and 2,278 VKH patients. A rare c.188T>C (p Val63Ala) variant in the olfactory receptor 11H1 (OR11H1) gene is found to be significantly associated with VKH disease (rs71235604, Pcombined = 7.83 × 10-30 , odds ratio = 3.12). Functional study showes that OR11H1-A63 significantly increased inflammatory factors production and exacerbated barrier function damage. Further studies using RNA-sequencing find that OR11H1-A63 markedly increased growth arrest and DNA-damage-inducible gamma (GADD45G) expression. Moreover, OR11H1-A63 activates the MAPK and NF-κB pathways, and accelerates inflammatory cascades. In addition, inhibiting GADD45G alleviates inflammatory factor secretion, likely due to the regulatory effect of GADD45G on the MAPK and NF-κB pathways. Collectively, this study suggests that the OR11H1-A63 missense mutation may increase susceptibility to VKH disease in a GADD45G-dependent manner.

Risk factors, clinical features and treatment of Behçet's disease uveitis

Behçet's disease is a systemic vasculitis frequently associated with intraocular inflammation. Recent findings identified independent clinical clusters in Behçet's disease, each involving distinct combinations of affected organs. Ocular Behçet's disease, mainly manifested as uveitis, is characterized as an independent cluster with a low likelihood of association with other system involvements, such as intestinal, cardiovascular, or central nervous system. A prevailing theory suggests that the pathogenesis of the disease is multifactorial, where a variety of genetic and infectious agents may interact with each other to cause the disease. Among sporadic cases, the human leukocyte antigen (HLA) genes, including HLA-B51, HLA-A26, HLA-B15, and HLA-B5701, have been found to be a key component conferring genetic susceptibility. Outside the HLA region, a set of susceptibility variants are identified, closely related to interleukin (IL)-23/IL-17 pathway, tumor necrosis factor (TNF) signaling, and pattern recognition receptor systems. Microbial infections, such as Streptococcus sanguinis, Mycobacterium tuberculosis, and Herpes simplex virus (HSV), are linked to play the triggering of disease in immunogenetically predisposed individuals. Clinically, due to the notable relapsing-remitting course of ocular Behçet's disease, the prevention of recurrent attack would be the primary treatment goal. Combination of corticosteroids and immunomodulatory drugs, such as anti-TNF agents, interferon, and conventional immunosuppressants (e.g. cyclosporine, azathioprine), have been the mainstream regimen for the disease. Future research may focus on comparing the effectiveness of immunomodulatory drugs and identifying the most suitable subgroups for a specific drug on the basis of the knowledge of the molecular heterogeneity of the disease.

JAK-STAT signaling pathway-related gene single nucleotide polymorphisms and susceptibility to ankylosing spondylitis in eastern Chinese Han population

OBJECTIVE

A case-control study was utilized to investigate the relationship between genetic variation of JAK-STAT signaling pathway-related genes and the susceptibility to ankylosing spondylitis (AS).

METHODS

Fifteen SNPs in the JAK-STAT signaling pathway-related genes from 660 AS patients and 646 healthy controls were genotyped using iMLDR technology (JAK1: rs2230587, rs2230588, rs2780815, rs310241; JAK2: rs2274472, rs2230722, rs2230724, rs10758669; STAT1: rs10199181, rs1547550, rs2066802, rs45463799, rs6718902; STAT3: rs3744483; STAT5A: rs1135669).

RESULTS

Allele analysis revealed that the T allele of STAT1 rs6718902 was a protective agent for male AS patients (OR = 0.765, 95% CI = 0.644-0.909). Inheritance models showed that GG + CG as well as GG genotypes of STAT1 rs1547550 had a significant risk of developing AS in males (OR = 5.374, 95%CI = 2.505-11.526; OR = 5.186, 95%CI = 2.412-11.153). The TT + CT and TT genotypes at STAT1 rs6718902 were observed to be associated with a significantly decreased risk of AS compared to CC genotypes among male patients and male controls (OR = 0.637, 95%CI = 0.485-0.837; OR = 0.597, 95%CI = 0.422-0.845). Furthermore, the genotypes of JAK1 gene rs2230588, rs2780815, and rs310241 were correlated with the severity of clinical conditions in female AS patients, while the JAK2 rs2230724 genotypes may affect disease ability in male AS patients.

CONCLUSION

These findings indicated that JAK-STAT signaling pathway-related gene single nucleotide polymorphisms may be associated with AS susceptibility in eastern Chinese Han population. Key Points • The T allele of rs6718902 on the STAT1 gene may be a protective agent for male AS patients. • STAT1 rs1547550 GG + CG and GG genotypes were observed to be connected with a risk of male AS patients. However, STAT1 rs6718902 TT + CT and TT genotypes reduced the susceptibility risk of male AS patients compared to wild-type CC. • The JAK1 genes rs2230588, rs2780815, and rs310241 may affect disease functional status in female AS patients, while the JAK2 rs2230724 genotype was related to disease activity in male AS patients.

JAK-STAT Signaling Pathway in Non-Infectious Uveitis

Non-infectious uveitis (NIU) refers to various intraocular inflammatory disorders responsible for severe visual loss. Cytokines participate in the regulation of ocular homeostasis and NIU pathological processes. Cytokine receptors transmit signals by activating Janus kinase (JAK) and signal transducer and activator of transcription (STAT) proteins. Increasing evidence from human NIU and experimental models reveals the involvement of the JAK-STAT signaling pathway in NIU pathogenesis. Several small-molecule drugs that potentially inhibit multiple cytokine-dependent pathways are under investigation for treating autoimmune diseases, implicating possible applications for NIU treatment. This review summarizes the current understanding of the diverse roles of the JAK-STAT signaling pathway in ocular homeostasis and NIU pathology, providing a rationale for targeting JAKs and STATs for NIU treatment. Moreover, available evidence for the safety and efficacy of JAK inhibitors for refractory uveitis and potential approaches for treatment optimization are discussed.

Transcriptome analysis of immune cells from Behçet's syndrome patients: the importance of IL-17-producing cells and antigen-presenting cells in the pathogenesis of Behçet's syndrome

Background

Behçet’s syndrome (BS) is an immune-mediated disease characterized by recurrent oral ulcers, genital ulcers, uveitis, and skin symptoms. HLA-B51, as well as other genetic polymorphisms, has been reported to be associated with BS; however, the pathogenesis of BS and its relationship to genetic risk factors still remain unclear. To address these points, we performed immunophenotyping and transcriptome analysis of immune cells from BS patients and healthy donors.

Methods

ImmuNexUT is a comprehensive database consisting of RNA sequencing data and eQTL database of immune cell subsets from patients with immune-mediated diseases and healthy donors, and flow cytometry data and transcriptome data from 23 BS patients and 28 healthy donors from the ImmuNexUT study were utilized for this study. Differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) were performed to identify genes associated with BS and clinical features of BS. eQTL database was used to assess the relationship between genetic risk factors of BS with those genes.

Results

The frequency of Th17 cells was increased in BS patients, and transcriptome analysis of Th17 cells suggested the activation of the NFκB pathway in Th17 cells of BS patients. Next, WGCNA was used to group genes into modules with similar expression patterns in each subset. Modules of antigen-presenting cells were associated with BS, and pathway analysis suggested the activation of antigen-presenting cells of BS patients. Further examination of genes in BS-associated modules indicated that the expression of YBX3, a member of a plasmacytoid dendritic cell (pDC) gene module associated with BS, is influenced by a BS risk polymorphism, rs2617170, in pDCs, suggesting that YBX3 may be a key molecule connecting genetic risk factors of BS with disease pathogenesis. Furthermore, pathway analysis of modules associated with HLA-B51 indicated that the association of IL-17-associated pathways in memory CD8⁺ T cells with HLA-B51; therefore, IL-17-producing CD8⁺ T cells, Tc17 cells, may play a critical role in BS.

Conclusions

Various cells including CD4⁺ T cells, CD8⁺ T cells, and antigen-presenting cells are important in the pathogenesis of BS. Tc17 cells and YBX3 may be potential therapeutic targets in BS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02867-x.

Genetic Associations and Differential mRNA Expression Levels of Host Genes Suggest a Viral Trigger for Endemic Pemphigus Foliaceus

The long search for the environmental trigger of the endemic pemphigus foliaceus (EPF, fogo selvagem) has not yet resulted in any tangible findings. Here, we searched for genetic associations and the differential expression of host genes involved in early viral infections and innate antiviral defense. Genetic variants could alter the structure, expression sites, or levels of the gene products, impacting their functions. By analyzing 3063 variants of 166 candidate genes in 227 EPF patients and 194 controls, we found 12 variants within 11 genes associated with differential susceptibility (p < 0.005) to EPF. The products of genes TRIM5, TPCN2, EIF4E, EIF4E3, NUP37, NUP50, NUP88, TPR, USP15, IRF8, and JAK1 are involved in different mechanisms of viral control, for example, the regulation of viral entry into the host cell or recognition of viral nucleic acids and proteins. Only two of nine variants were also associated in an independent German cohort of sporadic PF (75 patients, 150 controls), aligning with our hypothesis that antiviral host genes play a major role in EPF due to a specific virus−human interaction in the endemic region. Moreover, CCL5, P4HB, and APOBEC3G mRNA levels were increased (p < 0.001) in CD4+ T lymphocytes of EPF patients. Because there is limited or no evidence that these genes are involved in autoimmunity, their crucial role in antiviral responses and the associations that we observed support the hypothesis of a viral trigger for EPF, presumably a still unnoticed flavivirus. This work opens new frontiers in searching for the trigger of EPF, with the potential to advance translational research that aims for disease prevention and treatment.

JAK1 rs310241 and JAK3 rs3008 Genotypes May Increase Susceptibility to Psoriasis: A Case Control Study

BACKGROUND

Janus kinases (JAKs) are a family of non-receptor protein tyrosine kinases that are expressed in a variety of tissues. Several JAK-controlled cytokine receptor pathways are incriminated in the initiation and progression of psoriasis. Genetic polymorphisms influencing JAK expression would be anticipated to have a great impact on disease activity.

OBJECTIVE

The aim of the study was to evaluate the association between JAK1 rs310241 and JAK3 rs3008 polymorphisms and the risk of developing psoriasis.

METHODS

Blood samples of 150 patients and 120 controls were screened for nucleotide polymorphisms in JAK1 rs310241 and JAK3 rs3008 genes by using polymerase chain reaction (PCR)-restriction fragment length polymorphism technique.

RESULTS

The GG genotype of the JAK1 rs310241 and JAK3 rs3008 genes was significantly associated with an increase in psoriasis risk (p = 0.000, OR = 7.7, 95% CI = 2.8-21.5; p = 0.003, OR = 3.3, 95% CI = 1.5-6.9, respectively). The G allele of both genes was also associated with psoriasis susceptibility (p = 0.000, OR = 2.0, 95% CI = 1.4-2.8; p = 0.002, OR = 1.7, 95% CI = 1.2-2.4, respectively).

CONCLUSION

The results indicate a possible association between JAK1 rs310241 and JAK3 rs3008 gene polymorphisms and susceptibility to psoriasis. These findings validate the importance of these molecules in psoriasis and may enable the identification of the individuals most susceptible to the disease.

Genetic Polymorphisms in Transforming Growth Factor-β, Interferon-γ and Interleukin-6 Genes and Susceptibility to Behcet's Disease in Saudi Population

Background

Behcet’s disease (BD) is a complex, inflammatory, immune-mediated multi-systemic disease of unknown etiology. Cytokines play major roles in the pathophysiology of BD, and its production may be affected by polymorphism in cytokine genes. Hence, the present study was planned to investigate any possible association between the polymorphism in TGF-β, IFN-γ, and IL-6 genes and BD in the Saudi population.

Materials and Methods

The present study includes 79 BD cases and 117 age-matched controls. Polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation systems (ARMS) PCR methods were used for polymorphic analysis.

Results

The heterozygous (CT) and (CT+TT) combined genotypes of TGF-β (509-C/T), heterozygous (AT), variant (TT), and (AT+TT) combined genotypes of IFN-γ (874-A/T) were significantly (P<0.05) associated with BD in the Saudi population. No significant differences were observed for IL-6 (174-G/C) genotypes and alleles between BD cases and controls. Gender does not reflect any significant genotypic and allelic association with males and females.

Conclusion

CT genotype of TGF-β, and AT and TT genotypes of IFN-γ could be associative genetic risk factors for BD in Saudis. Regulatory region polymorphism in cytokines gene can increase inflammation and deregulated immune response, which could be risk factor for BD.

Association of LACC1, CEBPB-PTPN1, RIPK2 and ADO-EGR2 with ocular Behcet's disease in a Chinese Han population

Background

An Immunochip study recently identified the association of a number of new genetic loci with Behcet’s disease (BD).

Objective

To confirm the association between new genetic loci reported in an Immunochip study and BD in a Han Chinese population.

Methods

A two-stage association study was carried out in 1238 patients with BD and 1458 healthy controls. Twenty-two candidate single nucleotide polymorphisms (SNPs) were selected for genotyping by iPLEXGold genotyping or TaqMan SNP assays and a meta-analysis was performed for significantly associated markers.

Results

The results showed that four SNPs (LACC1/rs9316059, CEBPB-PTPN1/rs913678, ADO-EGR2/rs224127 and RIPK2/rs10094579) were associated with BD in an allelic association test (rs9316059 T allele: p_c=4.95×10⁻⁸, OR=0.687; rs913678 C allele: p_c=3.01×10⁻⁴, OR=1.297; rs224127 A allele: p_c=3.77×10⁻⁴, OR=1.274; rs10094579 A allele: p_c=6.93×10⁻⁴, OR=1.302). For four SNPs tested by meta-analysis, the association with BD was strengthened and all exceeded genome-wide significance (rs9316059: p=2.96×10⁻¹⁶; rs913678: p=2.09×10⁻¹⁶; rs224127: p=5.28×10⁻¹³; rs10094579: p=9.21×10⁻¹¹).

Conclusions

Our findings confirmed the association of four loci (LACC1, CEBPB-PTPN1, ADO-EGR2 and RIPK2) in Chinese Han patients with BD.

Genetic polymorphisms of C-type lectin receptors in Behcet's disease in a Chinese Han population

C-type lectin receptors (CLRs) have been demonstrated to be involved in several autoimmune diseases. The role of CLRs in Behcet’s disease (BD) is unknown and thus was the purpose of this study. A two-stage association study was carried out and a total of 766 BD patients and 1674 healthy controls were recruited. Genotyping of 14 SNPs of 13 genes in CLRs was carried out by iPLEX Gold genotyping or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The expression of mannose binding lectin 2 (MBL2) and killer cell lectin like receptor C4 (KLRC4) was measured by Real-time PCR. Significantly increased frequencies of the A allele as well as AA genotype of rs1800450 in MBL2 (Pc = 2.50 × 10⁻⁶, OR = 1.494; Pc = 2.24 × 10⁻⁶,OR = 2.899; respectively) and TT genotype of rs2617170 in KLRC4 (Pc = 2.53 × 10⁻⁶, OR = 1.695) and decreased frequencies of GG genotype of rs1800450 (Pc = 1.56 × 10−3, OR = 0.689) and C allele as well as CC genotype of rs2617170 (Pc = 2.05 × 10−9,OR = 0.664; Pc = 1.20 × 10−5, OR = 0.585; respectively) were observed in BD. Two variants, p.Gly54Asp (rs1800450) and p.Asn104Ser (rs2617170) affect MBL2 and KLRC4 protein stability and expression. Our study demonstrates that the MBL2/rs1800450 and KLRC4/rs2617170 are susceptibility factors for BD in a Chinese Han population.

Clinical significance of NCOA5 gene rs2903908 polymorphism in Behçet's disease

Behçet's disease (BD) is an autoimmune multisystemic disease. The precise etiology of BD is not fully understood; however, it is thought that interactions between genetic and environmental factors play an essential role in its pathogenesis. The nuclear receptor coactivator-5 (NCOA5) gene encodes a coregulator for nuclear receptor subfamily 1 group D member 2 (NR1D2) and estrogen receptor 1 and 2 (ESR1 and ESR2). Also, the NCOA5 gene insufficiency leads to an elevated expression of IL-6, and increased levels of IL-6 were found to be related to the pathogenesis of BD. In this study, we aimed to clarify the impact of the NCOA5 rs2903908 polymorphism on susceptibility and clinical findings of BD. This study included 671 participants (300 BD patients and 371 healthy controls). The analyses of NCOA5 rs2903908 polymorphism was performed by using the TaqMan allelic discrimination assay. The frequency of TT genotype of the NCOA5 rs2903908 polymorphism was found significantly higher in BD patients compared to those in healthy controls (p=0.016, OR=1.46, 95 % CI=1.08-1.99). Also, the frequencies of CT genotype was observed significantly higher in BD patients with genital ulceration and uveitis than without genital ulceration and uveitis (p=0.002 and p=0.005, respectively). The most significant association was found between C allele frequencies of BD patients with and without uveitis (p=0.0001). Our study represents for the first time that the NCOA5 rs2903908 polymorphism seemed to be linked to BD susceptibility and clinical findings.

Lack of Association between Genetic Polymorphisms of JAK-STAT Signaling Pathway Genes and Acute Anterior Uveitis in Han Chinese

Purpose. This study aimed to investigate the association between single nucleotide polymorphisms (SNPs) of JAK-STAT signaling pathway genes and acute anterior uveitis (AAU) with or without ankylosing spondylitis (AS) in the Han Chinese population. Methods. Eleven SNPs of the JAK1, JAK2, STAT1, IRF1, and NOS2 genes were analyzed in 443 AAU patients with AS, 486 AAU patients without AS, and 714 healthy controls. Genotyping was performed by PCR-RFLP assay or TaqMan® probe assay. The Chi-squared (χ²) test and multivariate logistic regression analysis were used to compare the distributions of alleles and genotypes between patients and controls. P values were adjusted using Bonferroni correction. Results. We did not observe significant differences in the genotype and allele frequencies of any SNP between AAU patients with or without AS and healthy controls. Stratification analyses by gender and HLA-B27 status showed a boundary significant association between two SNPs (rs10975003 and rs10758669) in JAK2 and AAU (P = 0.052 and P = 0.053, resp.). Conclusions. Our results indicated that genetic polymorphisms of the JAK-STAT signaling pathway genes may not be associated with AAU in the Han Chinese population.

A preliminary study of new single polymorphisms in the T helper type 17 pathway for psoriasis in the Korean population

Psoriasis is a polygenic and multi-factorial disease showing ethnic differences in terms of its severity and frequency. Therapies targeting interleukin (IL)-17A, IL-17 receptor (IL-17R) and Janus kinases (JAKs) are in clinical development for the treatment of psoriasis, and their success suggests the essential role of these molecules in psoriasis. To investigate the genetic susceptibility in T helper type 17 (Th17) cell signal transduction pathways for promoting psoriasis, we performed candidate gene and linkage disequilibrium analysis. In 208 patients and 266 normal controls, we analysed 31 single nucleotide polymorphisms in 12 genes (CAMP, IL17A, IL17F, IL17RA, IL22, JAK1, JAK2, JAK3, STAT3, TLR7, TLR9 and TYK2; abbreviations: CAMP, human cathelicidin antimicrobial peptide; STAT-3, signal transducer and activator of transcription 3; TLR, Toll-like receptor; TYK2, tyrosine kinase 2). Patients with psoriasis showed a strong association for IL17F rs763780 [odds ratio (OR) = 3·27, P = 0·04], which results in a histidine-to-arginine substitution, and JAK2 rs2274471 (OR = 2·66, P = 0·02). In addition, JAK2 rs7849191 showed a protective pattern, met the significance threshold (OR = 0·77, P = 0·05) and showed a tendency for an inverse association with the frequency of early-onset psoriasis under age 40 years (P = 0·07). In haplotype analysis, JAK1 rs310241A/rs2780889T showed a protective effect (OR = 0·73, P = 0·03) in psoriasis. In conclusion, we report two new psoriasis-susceptibility loci, in IL17F and JAK2, as well as a newly identified late-onset associated protective JAK2 locus and a protective JAK1 haplotype in the Korean population.

Targeting cytokine signaling in autoimmunity: back to the future and beyond

Cytokines represent structurally diverse soluble factors with critical roles in normal immune function and the pathogenesis of autoimmunity. The emergence of many successful biological therapies targeting cytokines and cytokine receptors exemplifies the importance of cytokines in driving human autoimmune disease; unsurprisingly, there is no paucity of reviews on this subject. Nonetheless, many patients with autoimmune disease do not respond to biologicals, and cure remains an unmet goal. Thus, targeting the intracellular pathways employed by cytokines provides new therapeutic opportunities. A subset of cytokines utilizes the Janus kinase-signal transducer of activators of transcription (JAK-STAT) pathway as a mode of signal transduction. First generation JAK inhibitors (jakinibs) are used to treat rheumatologic disease, and second-generation jakinibs are being developed. Simultaneously, rapid advances are being made in our understanding of the genomic and epigenomic impact of cytokines. In this review, we will briefly review the role of JAK-STAT-dependent cytokines in immune-mediated disease, the current status of Jakinibs, and future possibilities for therapeutic intervention using genomic insights.

Genetic Association of HLA-A*26, -A*31, and -B*51 with Behcet's Disease in Saudi Patients

BACKGROUND

HLA-B*51 has been universally associated with Behcet’s disease (BD) susceptibility, while different alleles of HLA-A have also been identified as independent BD susceptibility loci in various ethnic populations. The objective of this study was to investigate associations of HLA-A and -B alleles with BD in Saudi patients.

MATERIALS AND METHODS

Genotyping for HLA-A and HLA-B was performed using HLA genotyping kit (Lab type^(R) SSO) in 120 Saudi subjects, including 60 BD patients and 60 matched healthy controls.

RESULTS

Our results revealed that frequencies of HLA-A*26, -A*31, and -B*51 were significantly higher in BD patients than in controls, suggesting that HLA-A*26, -A*31, and -B*51 are associated with BD. The frequency of HLA-B*15 was significantly lower in BD patients than in controls. Stratification of genotyping results into active and nonactive forms of BD revealed that the frequency of HLA-A*31 was significantly higher in the nonactive form than in the active form of BD, while there was no significant difference in the distribution of other alleles between the two forms of BD.

CONCLUSION

This study suggests that HLA-A*26, -A*31, and -B*51 are associated with susceptibility risk to BD, while HLA-B*15 may be protective in Saudi patients. However, larger scale studies are needed to confirm these findings.

The potential of genetically guided treatment in Behçet's disease

Continuous identification of specific targets and candidate genes together with novel approaches offers new promises for the future of gene therapy design in Behçet's disease (BD). Personalized medicine based on pharmacogenomics is being developed at the clinical stage to improve treatment response. Screening the whole gene and regulatory regions is important when searching for novel variants associated with such complex diseases. Different host genetic factors play significant roles in susceptibility to BD. Thus, identifying these genes responsible for susceptibility and resistance to BD may offer a notable contribution toward understanding its pathogenesis, and may lead to the development of novel prophylactic and treatment strategies. Evidenced-based treatment strategy is recommended for the management in BD patients. This review sheds light on the immunopathogenesis and pharmacogenetics of BD with special attention to the treatment targeting gene polymorphisms. In conclusion, the potential of genetically guided treatment in BD takes us back to the future for an accurate management strategy of this serious rheumatic disease. The ongoing discovery of pivotal genes related to the susceptibility, manifestations, disease activity and treatment options provide substantial hope to the reduced frequency of BD, effective control and improvement in the prognosis. Targeted gene therapy could be a leading option in the treatment armamentarium of BD.

Molecular Genetic Advances in Uveitis

Uveitis is usually considered as an intraocular inflammation characterized by variety of clinical features. Behcet's disease (BD), Vogt-Koyanagi-Harada (VKH) syndrome, acute anterior uveitis (AAU), and birdshot chorioretinopathy (BCR) are examples of noninfectious forms of uveitis. Although the precise pathogenesis remains unclear, accumulating evidence shows that complex genetic backgrounds coupled with an aberrant immune response may be implicated in the development of uveitis. The complement and pattern recognition systems are both important factors of the innate immune system and are involved in the pathogenesis of uveitis. Copy number variants (CNVs) of complement component 4 have been found to be associated with BD and VKH syndrome, but not with AAU. Several CNVs and gene polymorphisms of toll-like receptors were found to be associated with BD. Leukocytes are an important part of the adaptive immune system and various molecules on these cells play an important role in the development of uveitis. Genes encoding for human leukocyte antigens (HLAs) have been shown to be associated with certain uveitis entities, including BD (HLA-B51), VKH syndrome (HLA-DR4, DRB1/DQA1), AAU (HLA-B27), and BCR (HLA-A29). Genome wide association studies showed that the IL-23R locus was a shared risk factor for multiple uveitis entities including BD, AAU, and VKH syndrome. In addition, various other non-HLA genes are also associated with BD or VKH syndrome, such as IL-10, STAT4, STAT3, and UBAC2. These studies support the hypothesis that genetic factors play a key role in the pathogenesis of uveitis.

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

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

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.