Association between interleukin 1 polymorphisms and rheumatoid arthritis susceptibility: a metaanalysis

Genetic polymorphisms of ACE I/D, IL-1β G > A and IL-4 VNTR among Egyptian subjects with rheumatoid arthritis

BACKGROUND

Various reports examined the contribution of ACE I/D, IL-1β G > A and IL-4 VNTR with the susceptibility to RA but with conflicting findings. The goal of this study is to assess the impact of these three variants with the susceptibility, clinical and biochemical markers in addition to different composite indices of RA.

SUBJECTS AND METHODS

This case-control survey enclosed 120 RA Egyptian patients who were emulated with 150 healthy controls from the same territory. Their genomic DNA was genotyped utilising the PCR approach.

RESULTS

RA patients with ACE allele (D) and IL-4 VNTR allele (2 R) were expressively higher emulated with healthy controls (p < .05). Nevertheless, RA patients with IL-1β (A allele) failed to achieve an apparent significant emulated with healthy controls (p > .05).

CONCLUSIONS

This work specifies a noteworthy association for ACE I/D and IL-4 VNTR but not IL-1β G > A polymorphisms with RA susceptibility among Egyptian subjects.

Ultra-Low Dose Cytokines in Rheumatoid Arthritis, Three Birds with One Stone as the Rationale of the 2LARTH® Micro-Immunotherapy Treatment

Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are two cytokines involved in the perpetuation of the chronic inflammation state characterizing rheumatoid arthritis (RA). Significant advances in the treatment of this pathology have been made over the past ten years, partially through the development of anti-TNF and anti-IL-1 therapies. However, major side effects still persist and new alternative therapies should be considered. The formulation of the micro-immunotherapy medicine (MIM) 2LARTH^® uses ultra-low doses (ULD) of TNF-α, IL-1β, and IL-2, in association with other immune factors, to gently restore the body’s homeostasis. The first part of this review aims at delineating the pivotal roles played by IL-1β and TNF-α in RA physiopathology, leading to the development of anti-TNF and anti-IL-1 therapeutic agents. In a second part, an emphasis will be made on explaining the rationale of using multiple therapeutic targets, including both IL-1β and TNF-α in 2LARTH^® medicine. Particular attention will be paid to the ULD of those two main pro-inflammatory factors in order to counteract their overexpression through the lens of their molecular implication in RA pathogenesis.

Association between IL1B -511C/T polymorphism and Behçet's disease: a meta-analysis

Background

Many studies have investigated the relationship between the interleukin-1β gene (IL1B) −511C/T polymorphism and the risk of Behçet’s disease (BD); however, the conclusions remain controversial.

Methods

In this study, we systemically retrieved relevant studies from the Chinese Biomedicine Database, China National Knowledge Infrastructure, Embase, Cochrane Library, and PubMed databases. We then calculated the odds ratios (ORs) and 95% confidence intervals (CIs) using the meta-package Stata version 12.0.

Results

The IL1B −511C/T polymorphism was not related to BD susceptibility using any of the tested models (C vs T: OR = 1.20, 95% CI = 0.97–1.49; CC vs TT: OR = 1.27, 95% CI = 0.95–1.70; CT vs TT: OR = 1.03, 95% CI = 0.781.36; dominant model: OR = 1.12, 95% CI = 0.87–1.46; recessive model: OR = 1.27, 95% CI = 0.89–1.82). Similarly, subgroup analysis including studies consistent with the Hardy–Weinberg equilibrium revealed no association between the IL1B polymorphism and BD susceptibility.

Conclusion

This meta-analysis indicates that the IL1B −511C/T polymorphism is unlikely to affect the risk of BD; however, further large-scale, carefully designed studies are needed to verify these results.

Interleukins and interleukin receptors in rheumatoid arthritis: Research, diagnostics and clinical implications

Rheumatoid arthritis (RA) is an autoimmune disease, resulting in a chronic, systemic inflammatory disorder. It may affect many tissues and organs, but it primarily affects the flexible joints. In clinical practice patient care generates many questions about diagnosis, prognosis, and treatment. It is challenging for health care specialists to keep up to date with the medical literature. This review summarizes the pathogenesis, the polymorphisms of interleukin and interleukin genes and the standard available and possible future immunologic targets for RA treatment. The identification of disease-associated interleukin and interleukin receptor genes can provide precious insight into the genetic variations prior to disease onset in order to identify the pathways important for RA pathogenesis. The knowledge of the complex genetic background may prove useful for developing novel therapies and making personalized medicine based on the individual’s genetics.

Associations between interleukin 1 polymorphisms and susceptibility to systemic lupus erythematosus: a meta-analysis

OBJECTIVE

This study determined whether interleukin 1 (IL1) polymorphisms are associated with susceptibility to systemic lupus erythematosus (SLE).

METHODS

A meta-analysis was conducted on the associations between the IL1A, IL1B, and IL1 receptor antagonist (IL1RN) polymorphisms and SLE.

RESULTS

A total of 15 studies involving 1956 SLE cases and 2347 controls were included in the meta-analysis. The meta-analysis showed an association between SLE and the IL1A -889 T allele in the overall population and Europeans (OR = 0.858, 95% CI = 0.737-0.986, p = 0.032; OR = 0.827, 95% CI = 0.687-0.994, p = 0.043). Meta-analysis of the IL1RN polymorphism revealed an association with SLE in all study subjects (OR for IL1RN*2 = 1.539, 95% CI = 1.266-1.871, p = 1.5 × 10(-2)) and in Europeans and Asians (OR = 1.483, 95% CI = 1.187-1.852, p = 0.001; OR = 1.787, 95% CI = 1.167-2.736, p=0.008). No associations were found between SLE and the IL1B -511 C/T, 3953 C/T, and IL1A +4845 G/T polymorphisms.

CONCLUSIONS

This meta-analysis suggests IL1A -889 C/T polymorphism is associated with susceptibility to SLE in Europeans, and that the IL1RN*2 allele is associated with susceptibility to SLE in Europeans and Asians.

[Interleukin-1 and the interleukin-1 receptor antagonist gene polymorphisms study in patients with rheumatoid arthritis]

OBJECTIVES

One of the most important pro-inflammatory cytokines in the pathophysiology of rheumatoid arthritis (RA) is interleukin 1 (IL-1). The purpose of this study is to evaluate the association between IL-1B (-511), IL-1 (+3953), IL-1 RN variable number of tandem repeat (VNTR) polymorphisms and the occurrence in Algerian patients with rheumatoid arthritis. We also analyze their correlations with clinical and biological phenotypes.

PATIENTS AND METHODS

One hundred and forty-seven patients with RA (119 women, 28 men) and 127 controls (70 women, 57 men) were included in the study. The analysis of two polymorphisms of IL-1B-511 and IL-1B+3953 was done by PCR-RFLP. Analysis of IL1-RN VNTR polymorphism was performed by PCR.

RESULTS

No significant difference in genotype, allelic and haplotype distribution at the three polymorphisms was observed between RA patients and controls. However, the genotype (T/T) polymorphism of IL-1B-511 is more frequent in the group of patients with positive ACPA compared with negative ACPA group (Pc=0.01, OR=4.65). Moreover, we noted that the haplotype (IL-1RN* 1/IL-1B-511T/IL-1B+3953C) was more frequent (Pc=0.03, OR=2.05) in the positive ACPA group.

CONCLUSION

The association between the allele 1 of IL-1 RN VNTR, T allele of IL1B-511 and C allele of IL1-B +3953 polymorphisms seems to predispose to the synthesis of ACPA and therefore to the occurrence of ACPA positive RA. Further studies with a larger number of patients are needed to define the real role of IL-1 in the susceptibility to or severity of RA.

Genetics in rheumatoid arthritis beyond HLA genes: what meta-analyses have shown?

OBJECTIVE

Rheumatoid arthritis (RA) is a complex disorder with many genetic and environmental factors to account for disease susceptibility. Individual genetic association studies usually suffer from small sample size leading to biased results of polymorphisms association with RA liability. Therefore, meta-analyses seem to resolve this limitation, up to a point, increasing the power of statistical analyses. In this review, we summarize the current knowledge of non-HLA genetic factors contributing to RA predisposition based on meta-analyses.

METHODS

Using the key words: rheumatoid arthritis, meta-analysis, and polymorphism, we searched the PubMed database for the associated articles. Up to the middle of November 2012, seventy-nine articles fulfilled the criteria and highlighted the current findings on the genetic factors contributing to RA susceptibility.

RESULTS

The association with RA was confirmed for 32 gene polymorphisms, being population specific in some cases. However, meta-analyses did not confirm an association in case of 16 gene variants, previously studied in individual studies for their association with RA.

CONCLUSIONS

The use of bioinformatics tools and functional studies of the summarized implicated genes in RA pathogenesis could shed light on the molecular pathways related to the disorder, helping to the development of new drug targets for a better treatment of RA.

IL1RN genetic variations and risk of IPF: a meta-analysis and mRNA expression study

Idiopathic pulmonary fibrosis (IPF) is a rare and devastating lung disease of unknown aetiology. Genetic variations in the IL1RN gene, encoding the interleukin-1 receptor antagonist (IL-1Ra), have been associated with IPF susceptibility. Several studies investigated the variable number tandem repeat (VNTR) or single nucleotide polymorphisms rs408392, rs419598 and rs2637988, with variable results. The aim of this study was to elucidate the influence of polymorphisms in IL1RN on IPF susceptibility and mRNA expression. We performed a meta-analysis of the five case–control studies that investigated an IL1RN polymorphism in IPF in a Caucasian population. In addition, we investigated whether IL1RN mRNA expression was influenced by IL1RN polymorphisms. The VNTR, rs408392 and rs419598 were in tight linkage disequilibrium, with D′ > 0.99. Furthermore, rs2637988 was in linkage disequilibrium with the VNTR (D′ = 0.90). A haploblock of VNTR*2 and the minor alleles of rs408392and rs419598 was constructed. Meta-analysis revealed that this VNTR*2 haploblock is associated with IPF susceptibility both with an allelic model (odds ratio = 1.42, p = 0.002) and a carriership model (odds ratio = 1.60, p = 0.002). IL1RN mRNA expression was significantly influenced by rs2637988, with lower levels found in carriers of the (minor) GG genotype (p < 0.001). From this meta-analysis, we conclude that the VNTR*2 haploblock is associated with susceptibility to IPF. In addition, polymorphisms in IL1RN influence IL-1Ra mRNA expression, suggesting that lower levels of IL-1Ra predispose to developing IPF. Together these findings demonstrate that the cytokine IL-1Ra plays a role in IPF pathogenesis.

A systems genetics approach provides a bridge from discovered genetic variants to biological pathways in rheumatoid arthritis

Genome-wide association studies (GWAS) have yielded novel genetic loci underlying common diseases. We propose a systems genetics approach to utilize these discoveries for better understanding of the genetic architecture of rheumatoid arthritis (RA). Current evidence of genetic associations with RA was sought through PubMed and the NHGRI GWAS catalog. The associations of 15 single nucleotide polymorphisms and HLA-DRB1 alleles were confirmed in 1,287 cases and 1,500 controls of Japanese subjects. Among these, HLA-DRB1 alleles and eight SNPs showed significant associations and all but one of the variants had the same direction of effect as identified in the previous studies, indicating that the genetic risk factors underlying RA are shared across populations. By receiver operating characteristic curve analysis, the area under the curve (AUC) for the genetic risk score based on the selected variants was 68.4%. For seropositive RA patients only, the AUC improved to 70.9%, indicating good but suboptimal predictive ability. A simulation study shows that more than 200 additional loci with similar effect size as recent GWAS findings or 20 rare variants with intermediate effects are needed to achieve AUC = 80.0%. We performed the random walk with restart (RWR) algorithm to prioritize genes for future mapping studies. The performance of the algorithm was confirmed by leave-one-out cross-validation. The RWR algorithm pointed to ZAP70 in the first rank, in which mutation causes RA-like autoimmune arthritis in mice. By applying the hierarchical clustering method to a subnetwork comprising RA-associated genes and top-ranked genes by the RWR, we found three functional modules relevant to RA etiology: "leukocyte activation and differentiation", "pattern-recognition receptor signaling pathway", and "chemokines and their receptors".These results suggest that the systems genetics approach is useful to find directions of future mapping strategies to illuminate biological pathways.

A review of the gastrointestinal safety data--a gastroenterologist's perspective

Although NSAIDs have a well-established place for certain indications in the management of OA and RA, they are associated with significant gastrointestinal (GI) toxicity. The risk of NSAID-related upper GI events, such as dyspepsia or peptic ulcer and complications such as perforation or bleeding, is well characterized. Non-selective NSAIDs increase the risk of peptic ulcer disease approximately 5-fold, and that of upper GI bleeding 4-fold, whereas selective cyclo-oxygenase-2 (COX) inhibitors are associated with a significantly lower GI toxicity than non-selective agents. There is evidence that, while the incidence of NSAID-related upper GI complications has decreased in recent years, that of lower GI complications is increasing. Observational studies and analyses from studies, primarily designed to investigate upper GI events, suggest that lower GI complications are relatively common in NSAID users and that COX-2 selective inhibitors are associated with a lower risk of these events. Such events have been poorly characterized, but are associated with significant mortality; indeed, they may have even more serious consequences than the better characterized upper GI events. There is thus a strong case for evaluating the impact of such complications in prospective outcome studies. To facilitate such studies a new endpoint, Clinically Significant Upper or Lower GI Events, has been introduced that captures both upper and lower GI events.

The association of interleukin-1alpha and interleukin-1beta polymorphisms with the risk of Graves' disease in a case-control study and meta-analysis

The proinflammatory cytokine interleukin (IL)-1 family has a central role in mediating inflammation and joint destruction in Graves' disease (GD). A number of studies, investigating rs1800587 (IL-1alpha, T-889 C) and rs16944 (IL-1beta, A-511 G) polymorphisms to test their possible association with GD and Graves' ophthalmopathy (GO), had inconsistent results. Our study aims to further evaluate the possible association of these two polymorphisms with GD and GO within the Han Chinese population using a case-control association study as well as a meta-analysis covering three previous studies from Taiwan, Iran, and Poland. Based on 760 Chinese GD patients, including 190 of GO cases among them, and 735 healthy control subjects, our data showed that the genotype or allele distributions of rs1800587 and rs16944 polymorphisms were significantly associated with GD (p = 0.003-0.049) and more so with GO (p = 0.001-0.021). The meta-analysis showed the risk-increasing effects for the TC and TT genotypes of rs1800587 in GD (odds ratio [OR] = 2.07, p = 0.03) and GO (OR = 3.22, p = 0.04), and a protective effect for the AA genotype of rs16944 in GD (OR = 0.70, p = 0.002) and GO (OR = 0.65, p = 0.02). The results confirmed that the rs1800587 (IL-alpha, T-889 C) and rs16944 (IL-1beta, A-511 G) polymorphisms may confer susceptibility to GD and GO in Asian population.

Periodontitis in systemic rheumatic diseases

Periodontitis is a chronic inflammatory disease that is characterized by loss of the periodontal ligament and alveolar bone, and is a major cause of tooth loss. Results from clinical and epidemiologic studies have suggested that periodontitis and tooth loss are more prevalent in individuals with rheumatoid arthritis (RA). However, the strength and temporality of the association are uncertain. Several biologically plausible causal and noncausal mechanisms might account for this association between periodontitis and RA. There is evidence to suggest that periodontitis could indeed be a causal factor in the initiation and maintenance of the autoimmune inflammatory response that occurs in RA. If proven, chronic periodontitis might represent an important modifiable risk factor for RA. In addition, patients with RA might show an increased risk of developing periodontitis and tooth loss through various mechanisms. Moreover, exposure to common genetic, environmental or behavioral factors might contribute to a noncausal association between both conditions.