Interleukin-23 receptor genetic polymorphisms and ankylosing spondylitis susceptibility: a meta-analysis

IL23R mutations associated with decreased risk of psoriasis lead to the differential expression of genes implicated in the disease

Psoriasis is an incurable immune-mediated skin disease, affecting around 1%-3% of the population. Various lines of evidence implicate IL23 as being pivotal in disease. Genetic variants within the IL23 receptor (IL23R) increase the risk of developing psoriasis, and biologic therapies specifically targeting IL23 demonstrated high efficacy in treating disease. IL23 acts via the IL23R, signalling through the STAT3 pathway, mediating the cascade of events that ultimately results in the clinical presentation of psoriasis. Given the essential role of IL23R in disease, it is important to understand the impact of genetic variants on receptor function with respect to downstream gene regulation. Here we developed model systems in CD4+ (Jurkat) and CD8+ (MyLa) T cells to express either the wild type risk or mutant (R381Q) protective form of IL23R. After confirmation that the model system expressed the genes/proteins and had a differential effect on the phosphorylation of STAT3, we used RNAseq to explore differential gene regulation, in particular for genes implicated with risk to psoriasis, at a single time point for both cell types, and in a time course experiment for Jurkat CD4+ T cells. These experiments discovered differentially regulated genes in the cells expressing wild type and mutant IL23R, including HLA-B, SOCS1, RUNX3, CCR5, CXCR3, CCR9, KLF3, CD28, IRF, SOCS6, TNFAIP and ICAM5, that have been implicated in both the IL23 pathway and psoriasis. These genes have the potential to define a IL23/psoriasis pathway in disease, advancing our understanding of the biology behind the disease.

Determination of IL-23 receptor expression and gene polymorphism (rs1884444) in Iranian patients with ankylosing spondylitis

BACKGROUND

Through investigating genetic variations, it has been demonstrated that single nucleotide polymorphisms (SNPs) in the IL-23 receptor (IL23R) gene have a critical role in the pathophysiology of ankylosing spondylitis (AS). Here, we investigated whether the IL23R variant (rs1884444) is associated with AS in the Iranian population.

METHODS AND MATERIAL

In this research, we analyzed rs1884444 in a group of 425 patients with AS and 400 matched controls. For DNA extraction, the phenol/chloroform technique was utilized. Peripheral blood mononuclear cells (PBMCs) were obtained from the whole blood of 39 patients and 43 healthy controls and total RNA was extracted. Genotyping was performed by amplification-refractory mutation system (ARMS)-PCR method. Afterward, the expression level of IL23R was analyzed by the real-time quantitative (Q)-PCR method.

RESULTS

We observed no significant association between the distribution of alleles and genotypes of rs1884444 and susceptibility to AS. In addition, the expression level of IL23R did not differ between PBMCs from AS patients compared to the control group (P = 0.167). Furthermore, the relative expression level of IL23R was positively correlated with the BASDAI (P < 0.01) and BASFI (P < 0.05) scores of the patients.

CONCLUSION

It appears that IL23R polymorphism (rs1884444) and the level of gene expression might not contribute to the susceptibility to AS in the Iranian population. The correlation of IL23R expression with the level of BASDAI and BASFI scores in patients may be due to the role of the IL-23/IL-23R signaling cascade in inflammation and exert a critical role in the development of AS.

Modern vaccine development via reverse vaccinology to combat antimicrobial resistance

With the continuous evolution of bacteria, the global antimicrobial resistance health threat is causing millions of deaths yearly. While depending on antibiotics as a primary treatment has its merits, there are no effective alternatives thus far in the pharmaceutical market against some drug-resistant bacteria. In recent years, vaccinology has become a key topic in scientific research. Combining with the growth of technology, vaccine research is seeing a new light where the process is made faster and more efficient. Although less discussed, bacterial vaccine is a feasible strategy to combat antimicrobial resistance. Some vaccines have shown promising results with good efficacy against numerous multidrug-resistant strains of bacteria. In this review, we aim to discuss the findings from studies utilizing reverse vaccinology for vaccine development against some multidrug-resistant bacteria, as well as provide a summary of multi-year bacterial vaccine studies in clinical trials. The advantages of reverse vaccinology in the generation of new bacterial vaccines are also highlighted. Meanwhile, the limitations and future prospects of bacterial vaccine concludes this review.

Best practices in DNA methylation: lessons from inflammatory bowel disease, psoriasis and ankylosing spondylitis

Advances in genomic technology have enabled a greater understanding of the genetics of common immune-mediated diseases such as ankylosing spondylitis (AS), inflammatory bowel disease (IBD) and psoriasis. The substantial overlap in genetically identified pathogenic pathways has been demonstrated between these diseases. However, to date, gene discovery approaches have only mapped a minority of the heritability of these common diseases, and most disease-associated variants have been found to be non-coding, suggesting mechanisms of disease-association through transcriptional regulatory effects.

Epigenetics is a major interface between genetic and environmental modifiers of disease and strongly influence transcription. DNA methylation is a well-characterised epigenetic mechanism, and a highly stable epigenetic marker, that is implicated in disease pathogenesis. DNA methylation is an under-investigated area in immune-mediated diseases, and many studies in the field are affected by experimental design limitations, related to study design, technical limitations of the methylation typing methods employed, and statistical issues. This has resulted in both sparsity of investigations into disease-related changes in DNA methylation, a paucity of robust findings, and difficulties comparing studies in the same disease.

In this review, we cover the basics of DNA methylation establishment and control, and the methods used to examine it. We examine the current state of DNA methylation studies in AS, IBD and psoriasis; the limitations of previous studies; and the best practices for DNA methylation studies. The purpose of this review is to assist with proper experimental design and consistency of approach in future studies to enable a better understanding of the functional role of DNA methylation in immune-mediated disease.

Genetically determined high activities of the TNF-alpha, IL23/IL17, and NFkB pathways were associated with increased risk of ankylosing spondylitis

Background

Ankylosing spondylitis (AS) results from the combined effects of susceptibility genes and environmental factors. Polymorphisms in genes regulating inflammation may explain part of the heritability of AS.

Methods

Using a candidate gene approach in this case-control study, 51 mainly functional single nucleotide polymorphisms (SNPs) in genes regulating inflammation were assessed in 709 patients with AS and 795 controls. Data on the patients with AS were obtained from the DANBIO registry where patients from all of Denmark are monitored in routine care during treatment with conventional and biologic disease modifying anti-rheumatic drugs (bDMARDs).

The results were analyzed using logistic regression (adjusted for age and sex).

Results

Nine polymorphisms were associated with risk of AS (p < 0.05). The polymorphisms were in genes regulating a: the TNF-α pathway (TNF -308 G > A (rs1800629), and − 238 G > A (rs361525); TNFRSF1A -609 G > T (rs4149570), and PTPN22 1858 G > A (rs2476601)), b: the IL23/IL17 pathway (IL23R G > A (rs11209026), and IL18–137 G > C (rs187238)), or c: the NFkB pathway (TLR1 743 T > C (rs4833095), TLR4 T > C (rs1554973), and LY96–1625 C > G (rs11465996)).

After Bonferroni correction the homozygous variant genotype of TLR1 743 T > C (rs4833095) (odds ratios (OR): 2.59, 95% confidence interval (CI): 1.48–4.51, p = 0.04), and TNFRSF1A -609 G > T (rs4149570) (OR: 1.79, 95% CI: 1.31–2.41, p = 0.01) were associated with increased risk of AS and the combined homozygous and heterozygous variant genotypes of TNF -308 G > A (rs1800629) (OR: 0.56, 95% CI: 0.44–0.72, p = 0.0002) were associated with reduced risk of AS.

Conclusion

We replicated associations between AS and the polymorphisms in TNF (rs1800629), TNFRSF1A (rs4149570), and IL23R (rs11209026). Furthermore, we identified novel risk loci in TNF (rs361525), IL18 (rs187238), TLR1 (rs4833095), TLR4 (rs1554973), and LY96 (rs11465996) that need validation in independent cohorts. The results suggest that genetically determined high activity of the TNF-α, IL23/IL17, and NFkB pathways increase risk of AS.

Association of the HLA-B27 antigen and the CTLA4 gene CT60/rs3087243 polymorphism with ankylosing spondylitis in Algerian population: A case-control study

Ankylosing spondylitis (AS) is a complex inflammatory disease that represents a major health problem both in Algeria and worldwide. Several lines of evidence support that genetic risk factors play a role in AS etiology and the CTLA4 gene has attracted a considerable attention. In this study, we were interested in evaluating the HLA-B27 frequency and in exploring the CTLA4 gene in a sample of the North African population. The dataset of the current study is composed of 81 patients with AS and 123 healthy controls. All samples were genotyped by TaqMan^® allelic discrimination assay. The genetic risk of the HLA-B27 specificity and the CTLA4/CT60 polymorphism were assessed by odds ratios (OR) with 95% confidence intervals (CI). High spondylitis risk was detected for HLA-B27 allele (OR= 14.62, p = 10^-6 ) in addition to a significant association of the CT60*G allele (OR= 1.89, p = .002). After gender and age stratifications, the association of the CT60*G allele was still significant in females sample (OR= 2.10, p = .001) and when age up to 30 years (OR = 2.21, p = .008). Interestingly, the CT60*G allele revealed an increased spondylitis risk in the B27 negative group (OR= 2.81, p = .006). The present work showed in West Algerian population that the HLA-B27 antigen and the variation in the CTLA4 3'UTR region played an important role in the ankylosing spondylitis susceptibility. The heterogeneity of this disease is deduced by genetic difference found between B27+ and B27- groups.

Interleukin-23 receptor polymorphism (rs10889677 A/C) in ankylosing spondylitis: Meta-analysis in Caucasian and Asian populations

BACKGROUND

The association between interleukin-23 receptor (IL23R) gene rs10889677 polymorphism and ankylosing spondylitis (AS) susceptibility was inconsistent in the recent literatures. A systematic review and meta-analysis was therefore performed.

METHODS

Online electronic databases were searched for relevant studies published up to November 2017. Meta-analyses were performed for the comparisons of allele (A versus C) and multiple genetic models, including dominant, recessive, heterozygous, and homozygous models using fixed or random effects models. Odds ratios (OR) with 95% confidence intervals (95%CI) were utilized to assess the potential relationship.

RESULTS

Sixteen studies containing 19 separate comparisons, totaling 6450 cases and 8009 controls were included. A significant association between rs10889677 A allele and AS susceptibility was detected (OR=1.136, 95%CI=1.043-1.236, P=0.003). Stratified analysis by ethnicity indicated that rs10889677 A allele was significantly associated with AS in Europeans (OR=1.192, 95%CI=1.080-1.315, P<0.001), but not Asians (OR=1.045, 95%CI=0.913-1.197, P=0.523). In addition, there were no significant associations between rs10889677 polymorphism and AS susceptibility in any of dominant, recessive, homozygous and heterozygous models.

CONCLUSION

This meta-analysis demonstrates that IL23R gene rs10889677 A allele confers increased risk of AS in Europeans, but its role in Asian populations needs further exploration.

MEFV M694V mutation has a role in susceptibility to ankylosing spondylitis: A meta-analysis

OBJECTIVE

The aim of the current study was to determine the contributions of several common mutations in the Mediterranean fever (MEFV) gene, namely, E148Q, M680I, M694V and V726A, to ankylosing spondylitis (AS) susceptibility.

METHODS

Two investigators independently searched the literature regarding the association of MEFV with AS in the PubMed, EMBASE, Web of Science, and Scopus databases. They independently selected eligible articles and then extracted data from the included studies. The associations between MEFV mutations and AS risk were assessed with odds ratios (ORs) and 95% confidence intervals (95% CI). Further analyses were conducted with STATA 12.0 software (Stata Corp.; College Station, Texas, USA).

RESULTS

Four mutations (E148Q, M680I, M694V and V726A) were genotyped in 869 AS cases and 879 controls from the 8 eligible studies. Of the four mutations, M694V (pooled OR: 3.330, 95% CI: 2.129-5.208) was found to be associated with AS through overall analysis. However, the other mutations demonstrated no relation with AS (pooled ORs: 1.295, 1.258, 1.778; 95% CI: 0.886-1.891, 0.688-2.298 and 0.938-3.371). No significant publication bias was discovered in the meta-analysis.

CONCLUSIONS

The present study indicates that the MEFV M694V mutation may contribute to the pathogenesis of AS. The associations between the other mutations and AS need to be validated with more relevant and well-designed studies.

Association of rs11209032 and rs1004819 Polymorphisms in Interleukin-23 Receptor Gene With Ankylosing Spondylitis

Objectives

This study aims to investigate the distribution of human leukocyte antigen B27 (HLA-B27) alleles (+/-) and interleukin-23 receptor (IL-23R) gene rs11209032 and rs1004819 polymorphisms among ankylosing spondylitis (AS) patients in a Turkish cohort.

Patients and methods

The study sample comprised 106 AS patients (89 males, 18 females; mean age 38.9±10 years; range 19 to 65 years) and 82 healthy controls (70 males, 12 females; mean age 32.15±7.07 years; range 19 to 51 years). Distribution of HLA-B27 alleles (+)/(-) in AS patients were observed by reverse hybridization technique. Genotyping of IL-23R rs11209032 and rs1004819 polymorphisms of AS patients and healthy controls were performed by real time polymerase chain reaction.

Results

Of the AS patients, 69 (65.1%) were HLA-B27 positive. Distribution of rs11209032 genotype frequencies in AS group were 31.1% for GG, 50.9% for GA, and 17.9% for AA; while in control group, it was 34.1% for GG, 53.7% for GA, and 12.2% for AA. Distribution of rs1004819 genotype frequencies in AS group were 30.2% for CC, 52.8% for CT, and 17.0% for TT; while in control group, it was 42.7% for CC, 46.3% for CT, and 11.0% for TT. There was no significant difference between AS patients and controls in terms of genotype frequencies of IL-23R gene rs11209032 and rs1004819 polymorphisms.

Conclusion

No association was found between AS and IL23R rs11209032 and rs1004819 polymorphisms in this Turkish AS cohort.

Protective role of R381Q (rs11209026) polymorphism in IL-23R gene in immune-mediated diseases: A comprehensive review

Interleukin-23 (IL-23) is a regulator of cellular immune responses involved in controlling infection and autoimmune diseases. Strong evidence has shown that IL-23 plays a role in the maintenance of immune responses by influencing the proliferation and survival of IL-17-producing T-helper (TH)-17 cells. The critical role of the IL-23/TH17 axis in immune-mediated diseases has emerged from different studies. It has also been seen that polymorphisms in the IL-23 receptor (IL-23R) gene might influence IL-23 responses. Interestingly, a functional single nucleotide polymorphism (SNP) in the IL-23 receptor gene (IL-23R; rs11209026, 1142 G wild-type A reduced function, Arg381Gln, R381Q) seems to confer a measure of protection against development of inflammatory bowel disease (IBD; Crohn's disease, ulcerative colitis), ankylosing spondylitis, rheumatoid arthritis, psoriasis, thyroiditis, recurrent spontaneous abortion and asthma, suggesting that a perturbation in the IL-23 signaling pathway is likely to be relevant to the pathophysiology of these diseases. The aim of this review was to provide an evaluation of what is currently known about the protective role of R381Q variant in IL-23R gene in immune-based diseases.

The associations between PD-1, CTLA-4 gene polymorphisms and susceptibility to ankylosing spondylitis: a meta-analysis and systemic review

Previous surveys had evaluated the effects of the PD-1, CTLA-4 gene polymorphisms on susceptibility to ankylosing spondylitis (AS), but the results remained controversial. To briefly examine these consequences, a comprehensive meta-analysis was conducted to estimate the relationships between PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms and AS risk. The available articles dated to December 2014 were searched in the PUBMED, MEDLINE and EMBASE databases. The data of the genotypes and/or alleles for the PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms in the AS and control subjects were extracted, and statistical analysis was conducted by STATA 11.2 software. Summary odds ratios (ORs) with their 95 % confidence intervals (95 % CIs) were calculated to determine the strength of associations with fixed-effects or random-effects models. A total of eight published studies were finally involved in this meta-analysis. Meta-analysis of PD-1 rs2227982 polymorphism under the T allele versus C allele (OR 1.744, 95 % CI 1.477-2.059, P < 0.0001), TT+TC versus CC (OR 2.292, 95 % CI 1.654-3.175, P < 0.0001), TT versus CC (OR 1.883, 95 % CI 1.299-2.729, P = 0.001) revealed a significant association with AS. Our meta-analysis demonstrated that the rs2227982 polymorphism in the PD-1 gene might contribute to AS susceptibility. However, further studies with large sample sizes and among different ethnicity populations should be required to confirm this association.

Mediators of inflammation and bone remodeling in rheumatic disease

Remodeling of bone is a continuous process that occurs throughout life. Under normal physiologic conditions, bone-resorbing osteoclasts and bone-forming osteoblasts are tightly coupled and regulated to ensure proper balance, such that there is no net change in bone mass. However, inflammation perturbs normal bone homeostasis. The impact of inflammation on bone is dependent upon the anatomic site affected, cell types, factors and cytokines present in the local microenvironment, and local mechanical forces. Cytokines are central to the pathogenesis of inflammation-induced bone loss and contribute to the uncoupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation, thereby disrupting normal remodeling. In this review, we will discuss the effects of cytokines on bone in two settings, rheumatoid arthritis and spondyloarthritis, a disease category that includes ankylosing spondylitis, psoriatic arthritis, reactive arthritis, inflammatory bowel disease, and juvenile onset spondyloarthropathy. The outcome for bone in these disease settings is quite different, and an understanding of the pathogenic mechanisms leading to the net impact on bone has been essential in developing new therapeutic approaches to bone health in these diseases.

Serum IL-6 and IL-23 Levels and Their Correlation with Angiogenic Cytokines and Disease Activity in Ankylosing Spondylitis, Psoriatic Arthritis, and SAPHO Syndrome

OBJECTIVES

To assess serum interleukin-6 (IL-6) and interleukin-23 (IL-23) and their correlation with angiogenic cytokines and disease activity in ankylosing spondylitis (AS), psoriatic arthritis (PsA), and SAPHO syndrome.

PATIENTS AND METHODS

We studied 152 spondyloarthritis (SpA) patients: 69 PsA, 61 AS, 22 SAPHO, and 29 controls. We recorded age, sex, disease duration, and treatment. We assessed BASDAI, VAS, and PASI scores. Serum IL-6, IL-23, VEGF, EGF, FGFb, and FGFa levels were determined using ELISA. We estimated ESR and CRP.

RESULTS

Serum IL-6 and IL-23 levels were higher in SpA than in control (P < 0.00001 and P = 0.0004, resp.). There was a positive correlation between serum IL-6 and CRP in AS (P = 0.000001), PsA (P = 0.000001), and SAPHO (P = 0.0003) patients. There was a positive correlation between serum IL-6 and ESR in AS (P = 0.000001), PsA (P = 0.002), and SAPHO (P = 0.02) patients. There was no correlation of serum IL-6 and IL-23 with VAS, BASDAI, and angiogenic cytokines in SpA.

CONCLUSIONS

Serum IL-6 but not serum IL-23 correlated with ESR and CRP in SpA. No correlation was found of serum IL-6 and IL-23 with VAS, BASDAI, and angiogenic cytokines.

Association between rs7517847 and rs2201841 polymorphisms in IL-23 receptor gene and risk of ankylosing spondylitis: a meta-analysis

To comprehensively evaluate the association between rs7517847 and rs2201841 polymorphisms in the Interleukin-23 (IL-23) receptor gene and ankylosing spondylitis (AS), a meta-analysis was performed. The Pubmed, Embase, MEDLINE, Cochrane, China National Knowledge Infrastructure (CNKI), VIP, Wanfang and China Biology Medicine disc (CBMdisc) databases were searched to identify eligible studies on rs7517847 and rs2201841 polymorphisms in the IL-23 receptor gene and AS that were published through September 2014. Data of interest were extracted from each study, and the meta-analysis was performed using STATA 12.0. Four studies were eligible for the meta-analysis and included a total patient population of 2,465. With regards to rs7517847, the current study showed that the genotype GG and allele G might play a protective role during AS (OR = 0.76, 95% CI [0.59-0.99]; OR = 0.88, 95% CI [0.78-0.99] for homozygote and allelic models, respectively). However, according to the meta-analysis, there was no statistical association between the genotype or allele of rs2201841 and an individual's susceptibility to AS in all genetic models. In conclusion, it was the IL-23 rs7517847 polymorphism rather than the rs2201841 polymorphism that had a statistical association with AS. Nevertheless, more evidence is needed to confirm this result. Consequently, it is necessary to carry out more high-quality studies to confirm the associations between these two single nucleotide polymorphisms and AS.

The rs7517847 polymorphism in the IL-23R gene is associated with gout in a Chinese Han male population

OBJECTIVES

Gout is a polygenic auto-inflammatory disease, in which inflammation plays an important role in disease pathogenesis. The cytokine interleukin (IL)-23 promotes inflammation and helps to guide inflammatory cells, while studies have shown that the IL-23R gene is associated with susceptibility to several immune-related diseases. This study aimed to determine whether the IL-23R rs7517847 (G/T) polymorphism is associated with gout in a Chinese Han male population.

METHODS

We recruited 400 patients with gout and 582 gout-free controls. After obtaining blood samples for DNA extraction, genotyping of the rs7517847 polymorphism was performed by fluorescence-based quantitative PCR using TaqMan probes. An association analysis was carried out using the χ(2) test. A genotype-phenotype analysis was also conducted.

RESULTS

Both genotypic and allelic frequencies of rs7517847 differed significantly between gout patients and controls (χ(2) = 6.792, df = 2, P = 0.034 by genotype; χ(2) = 4.202, df = 1, P = 0.04 by allele).

CONCLUSIONS

IL-23R may be associated with gout in a Chinese Han male population, although our findings should be confirmed using larger sample sizes and other independent populations.

Impact of inflammation on the osteoblast in rheumatic diseases

Normal bone remodeling depends upon a balance between the action of bone-resorbing cells, osteoclasts, and bone-forming cells, osteoblasts. When this balance is disrupted, as is seen in inflammatory diseases such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS), abnormal bone loss or bone formation occurs. In RA, proinflammatory cytokines induce osteoclast differentiation and inhibit osteoblast maturation, leading to articular bone erosions. In contrast, the inflammatory milieu in AS leads to excessive osteoblast activation and bone formation at sites of entheses. While much information exists about the effects of proinflammatory cytokines on osteoclast differentiation and function, more recent studies have begun to elucidate the impact of inflammation on the osteoblast. This review will summarize the mechanisms by which inflammation perturbs bone homeostasis, with a specific focus on the osteoblast.

Marked differences of haplotype tagging SNP distribution, linkage, and haplotype profile of IL23 receptor gene in Roma and Hungarian population samples

Polymorphisms of the interleukin-23 receptor (IL23R) gene have been found to play an important role in the development of several autoimmune diseases. We examined five susceptible (rs10889677, rs1004819, rs2201841, rs11805303, rs11209032), one protective (rs7517847) and two neutral variants (rs7530511, rs1884444) of the IL23R gene in pooled DNA of healthy Roma (Gipsy) and Hungarian population samples. Our aim was to determine the genetic variability of the major haplotype tagging polymorphisms, and the haplotype profile of IL23R between the two groups. We analyzed 273 healthy Roma and 253 Hungarian DNA samples using PCR/RFLP assay. Comparing the five susceptible conferring alleles, there were significant increase (p<0.05), while in the protective alleles, there were decrease in the allele frequencies in Roma population (p<0.05). One of the neutral alleles showed increase, the another one did not differ between the two groups. The haplotype analysis of the SNPs revealed fundamentally different association types of SNPs in the two groups; moreover, the frequencies of the various haplotypes also exhibited strong differences, as of ht4 and ht5 haplotypes were significantly higher, whereas the frequencies of ht2 and ht3 haplotypes were significantly lower in the Roma population than in Hungarians (p<0.05). The data presented here show profound differences in the IL23R genetic profiles in the Roma population, that likely has also clinical implications in respect their possible role in the development of certain immunological diseases.

The association between tumor necrosis factor alpha promoter polymorphisms and ankylosing spondylitis: a meta-analysis

BACKGROUND

Studies investigating the association between tumor necrosis factor (TNF)-alpha promoter polymorphisms and ankylosing spondylitis have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship.

METHODS

We performed a systematic search of the National Library of Medline and Embase databases before January 2013. This meta-analysis included 14 case-control studies, which included 1607 ankylosing spondylitis cases and 1910 controls.

RESULTS

The combined results based on all studies showed that ankylosing spondylitis cases had a significantly lower frequency of -308GA [OR (codominant model)=0.81, 95% CI=0.66, 0.99, P=0.04], -857CT [OR (codominant model)=0.55, 95% CI=0.32, 0.94, P=0.03], -863AA [OR (codominant model)=0.11, 95% CI=0.01, 0.94, P=0.04], -863CA [OR (codominant model)=0.32, 95% CI=0.18, 0.58, P<0.001], and -1031TC [OR (codominant model)=0.44, 95% CI=0.25, 0.77, P=0.004] genotype. However, ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] and -850TT [OR (recessive model)=2.49, 95% CI=1.16, 5.34, P=0.02; OR (codominant model)=2.83, 95% CI=1.28, 6.25, P=0.01] genotype. In the subgroup analysis by race, we found that ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] genotype in Caucasians and lower frequency of -857CT [OR (codominant model)=0.53, 95% CI=0.30, 0.94, P=0.03] in Asians.

CONCLUSIONS

Our meta-analysis suggests that TNF-alpha promoter polymorphisms at positions -238, -308, -850, -857, -863 and -1031 could have a small influence on ankylosing spondylitis susceptibility. But there is a lack of association of the TNF-alpha-376G/A and -646G/A polymorphisms with ankylosing spondylitis.

Association study in Romanians confirms IL23A gene haplotype block rs2066808/rs11171806 as conferring risk to psoriatic arthritis

BACKGROUND

The cytokines IL12 and IL23 have been recently implicated in the pathogenesis of psoriatic arthritis (PsA). In this study we investigated the genetic variations in the genes coding for IL12, IL23 and IL23 receptor as a plausible source of susceptibility and modification of clinical symptoms of PsA in Romanian population.

METHODS

Twenty five SNPs mapping to IL12A, IL12B, IL23A, IL23R and IL12RB1 genes were genotyped in 94 PsA patients and 161 healthy controls of Romanian ethnicity using the Sequenom genotyping platform.

RESULTS

The exonic SNP rs11171806 from IL23A gene was significantly underrepresented in patients versus controls (p=0.03, OR 0.391) and the carriers of rs11171806/rs2066808 AC haplotype had decreased risk for PsA (p=0.03). The two SNPs of the highly conserved gene IL23A are in complete LD in our population. Genetic variants of IL12B gene were associated with polyarticular subtype of PsA. No associations were found between SNPs from IL12A, IL23R and IL12RB1 genes and susceptibility to PsA and its phenotypes.

CONCLUSION

We confirm the previously described association of rs2066808 variant with psoriasis and PsA and we show evidence of an extended genomic region inside IL23A gene as carrier of true disease susceptibility factors. These data suggest a role for IL23 in the PsA pathogenesis in Romanians.

Endoplasmic reticulum aminopeptidase 1 and interleukin-23 receptor in ankylosing spondylitis

Endoplasmic reticulum aminopeptidase 1 (ERAP1) and interleukin-23 receptor (IL-23R) gene polymorphisms were found to be associated with ankylosing spondylitis (AS) in a nonsynonymous single nucleotide polymorphism association study, and this has been replicated in several studies across different populations. ERAP1 variants could lead to significant changes in the repertoire of peptides presented by MHC-I. Reading this in conjunction with the known association of AS with HLA-B27, a functional interaction between ERAP1 and HLA-B27 is very likely. ERAP1 has additionally been shown to be involved in cytokine receptor shedding. The IL-23R is one of the two receptors that mediate the action of IL-23. AS is associated with the same polymorphisms of IL-23R as those linked to psoriasis and inflammatory bowel disease. This suggests common genetic risks linking AS and extra-articular manifestations. This review focuses on the pathogenic potential of these two genes in AS.

Associations between interleukin-23R polymorphisms and ankylosing spondylitis susceptibility: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether interleukin-23R (IL-23R) polymorphisms confer susceptibility to ankylosing spondylitis (AS).

METHODS

The authors conducted meta-analyses on associations between IL-23R polymorphisms and AS susceptibility, using fixed and random effects models.

RESULTS

A total of 10 studies (14 separate comparisons) were included in this meta-analysis, which included European and Asian populations. Meta-analysis revealed a significant association between AS and the two alleles of rs11209032 polymorphism in all study subjects (OR = 1.182, 95% CI 1.120-1.249, P = 0.000). Stratification by ethnicity identified a significant association between this polymorphism and AS in the European (OR = 1.234, 95% CI 1.159-1.313, P = 0.000), but not in the Asian populations (OR = 1.030, 95% CI 0.921-1.152, P = 0.608). Meta-analyses of rs1004819, rs10489629, rs1343151, rs1495965, and rs2201841 polymorphisms showed the same pattern as that shown by rs11209032 meta-analysis. Meta-analysis also revealed a significant association between the two alleles of the rs11209026 and the rs11465804 polymorphisms and the risk of developing AS in Europeans. Interestingly, the rs7517847 polymorphism was found to be significantly associated with AS susceptibility in both Europeans and Asians.

CONCLUSIONS

This meta-analysis shows that the IL-23R polymorphisms are associated with the development of AS in Europeans.

An update on the genetics of HLA B27-associated acute anterior uveitis

The discovery of the association of HLA B27 with spondyloarthropathy led to more questions than answers about the role of this gene in disease susceptibility. The realization that HLA B27 was not responsible for all of the genetic effects helped to lay a foundation for further investigation into the genetics of uveitis. Over several decades, genetic findings have provided clues to advance the understanding of mechanisms of uveitis and to catalyze new research on diagnostics, animal models, and therapies. From the early candidate gene studies on immune mediators to the recent genome-wide investigations, much has been discovered. However, these discoveries have come with the caveat that a genetic finding does not automatically reveal the disease-relevant functional effect of the associated variant.