Study of association of CD40-CD154 gene polymorphisms with disease susceptibility and cardiovascular risk in Spanish rheumatoid arthritis patients

Frequency of CD40-1C>T polymorphism (rs1883832) and association with response to treatment in children with primary immune thrombocytopenia

OBJECTIVES

To investigate whether (cluster of differentiation) CD40-1C>T (rs1883832) contributes to predisposition and treatment response of primary immune thrombocytopenia (pITP) in children.

METHODS

A case-control study that included 100 children with newly diagnosed pITP and 50 age- and sex-matched healthy controls. CD40 rs1883832 was genotyped using TaqMan allele discrimination real-time polymerase chain reaction (PCR). Patients were categorized into responders and non-responders according to their response to corticosteroids and thrombopoietin-receptor agonists (TPO-RA) at 3-month intervals.

RESULTS

The genotypic distribution of the CD40 rs1883832 was significantly different among cases and controls (CC 48% vs. 30%; CT 44% vs. 42%; TT 8% vs. 28%; p = .003). Compared with controls, children with newly diagnosed pITP had significantly higher C allele frequency (70% vs. 51%; odds ratio [OR] 2.2, 95% confidence interval [CI]: 1.3-3.8; p = .001). The association between C allele frequency and pITP risk was evident in females (OR 4.3, 95% CI: 2.1-8.8; p < .001), but not in males (OR 0.9, 95% CI: 0.4-2.1; p = .822). Compared with responders, the C allele frequency was significantly higher among non-responders to corticosteroids (87% vs. 66%; OR 3.4, 95% CI: 1.2-11.7; p = .012), but not to TPO-RA (92% vs. 85%; OR 2, 95% CI: 0.2-107; p = .550).

CONCLUSION

CD40 rs1883832 polymorphism may contribute to predisposition and response to upfront corticosteroids therapy of pediatric pITP. These findings improve our understanding of the compound pathophysiology of ITP, suggest important clinical potentials, and open the door for further research on the mechanistic role of CD40 rs1883832 in ITP development and progression.

Co-stimulators CD40-CD40L, a potential immune-therapy target for atherosclerosis: A review

The interaction between CD40 and CD40 ligand (CD40L) a crucial co-stimulatory signal for activating adaptive immune cells, has a noteworthy role in atherosclerosis. It is well-known that atherosclerosis is linked to immune inflammation in blood vessels. In atherosclerotic lesions, there is a multitude of proinflammatory cytokines, adhesion molecules, and collagen, as well as smooth muscle cells, macrophages, and T lymphocytes, particularly the binding of CD40 and CD40L. Therefore, research on inhibiting the CD40-CD40L system to prevent atherosclerosis has been ongoing for more than 30 years. However, it's essential to note that long-term direct suppression of CD40 or CD40L could potentially result in immunosuppression, emphasizing the critical role of the CD40-CD40L system in atherosclerosis. Thus, specifically targeting the CD40-CD40L interaction on particular cell types or their downstream signaling pathways may be a robust strategy for mitigating atherosclerosis, reducing potential side effects. This review aims to summarize the potential utility of the CD40-CD40L system as a viable therapeutic target for atherosclerosis.

Exploring potential shared genetic influences between rheumatoid arthritis and blood lipid levels

BACKGROUND AND AIMS

The association between rheumatoid arthritis (RA) and blood lipid levels has often been described as paradoxical, despite the strong association between RA and cardiovascular disease (CVD) risk. We aimed to clarify the genetic architecture that would explain the relationship between RA and blood-lipid levels, while considering inflammation as measured by C-reactive protein (CRP).

METHODS

Genome-wide association study (GWAS) summary statistics were collected from the CHARGE Consortium and Global Lipids Genetics Consortium. Blood-lipid levels includes HDL-C, LDL-C, triglycerides (TG), and total cholesterol (TC). Causality was examined by assessing Mendelian Randomization (MR) analysis. Pleiotropy, the identification of shared causal variants between traits, was assessed by conducting colocalization analyses.

RESULTS

Using the MR Egger method, RA did not appear to causally predict alterations in lipid factors, rather the MR Egger intercept revealed that the genetic relationship between RA and HDL-C, LDL-C and TC may be explained by horizontal pleiotropy (p=0.003, 0.006, and 0.018, respectively). MR was suggestive of a horizontally pleiotropic relationship between CRP and lipid factors, while a causal relationship could not be ruled out. Recurring genes arising from shared causal genetic variants between RA and varying lipid factors included NAT2/PSD3, FADS2/FADS1, SH2B3, and YDJC.

CONCLUSIONS

Horizontal pleiotropy appears to explain the genetic relationship between RA and blood-lipid levels. In addition, blood-lipid levels appear to suggest a horizontally pleiotropic relationship to CRP, if not mediated through RA as well. Consideration of the pleiotropic genes between RA and blood lipid levels may aid in enhancing diagnostic means to predict CVD.

IgA Vasculitis: Influence of CD40, BLK and BANK1 Gene Polymorphisms

CD40, BLK and BANK1 genes involved in the development and signaling of B-cells are identified as susceptibility loci for numerous inflammatory diseases. Accordingly, we assessed the potential influence of CD40, BLK and BANK1 on the pathogenesis of immunoglobulin-A vasculitis (IgAV), predominantly a B-lymphocyte inflammatory condition. Three genetic variants within CD40 (rs1883832, rs1535045, rs4813003) and BLK (rs2254546, rs2736340, rs2618476) as well as two BANK1 polymorphisms (rs10516487, rs3733197), previously associated with inflammatory diseases, were genotyped in 382 Caucasian patients with IgAV and 955 sex- and ethnically matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of CD40, BLK and BANK1 when IgAV patients and healthy controls were compared. Similar results were found when CD40, BLK and BANK1 genotypes or alleles frequencies were compared between patients with IgAV stratified according to the age at disease onset or to the presence/absence of gastrointestinal or renal manifestations. Moreover, no CD40, BLK and BANK1 haplotype differences were disclosed between patients with IgAV and healthy controls and between patients with IgAV stratified according to the clinical characteristics mentioned above. Our findings indicate that CD40, BLK and BANK1 do not contribute to the genetic background of IgAV.

IRAK1 Gene Polymorphism in Rheumatoid Arthritis

Background: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. The present study intends to specify rs1059703, rs4810485, and rs1883832 gene polymorphisms of interleukin-1 receptor-associated kinase (IRAK1) and cluster of differentiation 40 (CD40) in RA. IRAK1 is a serine/threonine kinase and CD40 is a tumor necrosis factor receptor, both of which are involved in RA. There are conflicting results on functional effects of these polymorphisms, so we performed this research for a more accurate estimation on rheumatoid arthritis risk. Methods: Two-hundred RA patients diagnosed according to ACR criteria and 200 normal controls participated in this case-control study. DNA Purification kit (Gene Transfer Pioneers, GTP) was used for genomic DNA extraction and three SNPs, including IRAK1 rs1059703 (C/T), CD40 rs1883832 (C/T) and rs4810485 (G/T), were genotyped by PCR-RFLP. The genotypes and allele frequencies of SNPs were analyzed by chi-square test to detect their contribution to RA. Results: A significant correlation was found between rs1059703 T allele (OR = 2.36, 95% CI = 1.7-3.1, p = .0001) and TT and CT genotypes (TT genotype, OR = 2.54, 95%CI = 1.2-3.3, P = .0078, CT genotype; OR = 2.18 95%CI = 1.4-3.2P = .0002) of rs1059703 C/T polymorphism in terms of susceptibility to RA in recessive and over-dominant models. Alleles and genotypes of CD40 SNPs were not significantly different between RA cases and controls. The findings showed significant differences in rs1059703 IRAK1 genotypes with medical and laboratory features of patients. Conclusion: Our results showed that the rs1059703 T allele (risk allele) of IRAK1 gene increases the risk of RA and the severity of disease, affecting the onset age of RA in Iranian patients.

Atherosclerosis in Rheumatoid Arthritis: Promoters and Opponents

Substantial epidemiological data identified cardiovascular (CV) diseases as a main cause of mortality in patients with rheumatoid arthritis (RA). In light of this, RA patients may benefit from additional CV risk screening and more intensive prevention strategies. Nevertheless, current algorithms for CV risk stratification still remain tailored on general population and are burdened by a significant underestimation of CV risk in RA patients. Acute CV events in patients with RA are largely related to an accelerated atherosclerosis. As pathophysiological features of atherosclerosis overlap those occurring in the inflamed RA synovium, the understanding of those common pathways represents an urgent need and a leading challenge for CV prevention in patients with RA. Genetic background, metabolic status, gut microbiome, and systemic inflammation have been also suggested as additional key pro-atherosclerotic factors. The aim of this narrative review is to update the current knowledge about pathophysiology of atherogenesis in RA patients and potential anti-atherosclerotic effects of disease-modifying anti-rheumatic drugs.

Impact of CD40 gene polymorphisms on the risk of immune thrombocytopenic purpura

OBJECTIVES

To evaluate the relationship between two common single nucleotide polymorphisms (SNPs) of CD40 gene (rs1883832 C/T and rs4810485 G/T) and the risk of immune thrombocytopenia (ITP) in the Egyptian population.

METHODS

A case-control study was conducted retrospectively on 101 cases with ITP and 97 healthy subjects. Two SNPs of CD40 gene (rs1883832 C/T and rs4810485 G/T) were genotyped via Taqman allele discrimination real-time PCR. The frequencies of different genetic models of both SNPs were calculated and compared between ITP cases and controls. Linkage analysis was performed between the studied SNPs. Odds ratio (OR) and 95% confidence interval (CI) were assessed using multinomial logistic regression analysis to determine the association of CD40 gene SNPs genotypes, alleles, and haplotypes with the risk of ITP. The odds ratio was further adjusted to the confounders for risk stratification.

RESULTS

CD40 (rs1883832) TT genotype carriers have a significantly higher risk of ITP when compared to CC genotype carriers (adjusted OR: 3.792, 95%CI: 1.252-11.49, P = 0.018). T allele also represents 1.711-fold increased risk of ITP which is more evident in males (P = 0.016). No significant difference was observed in the frequency of CD40 (rs4810485 G/T) genetic models between cases and controls. Linkage disequilibrium was found between the two SNPs and revealed four main haplotypes (C-G; C-T; T-G; T-T) with a significantly higher frequency of T-G haplotype in ITP cases than in healthy controls which confers an increased risk of ITP development (OR: 2.349, 95%CI: 1.271-4.339, P = 0.006).

CONCLUSIONS

CD40 gene SNP rs1883832 is associated with an increased risk of ITP development in the Egyptian population, while the SNP rs4810485 has no association. Moreover, T-G haplotype is a risk genetic model for ITP.

Association of soluble CD40 levels with -1 C > T CD40 polymorphism and chronic kidney disease in systemic lupus erythematosus

Background

CD40 is a transmembrane protein mainly expressed on the antigen‐presenting cells surface. CD40 plays a crucial role in immunoglobulin class switching and antibodies production. Genetic polymorphisms in the CD40 gene have been associated with increased risk of systemic lupus erythematosus (SLE) in several populations. This study aimed to evaluate the association of CD40 polymorphisms (−1 C > T, rs1883832 and 6,048 G > T, rs4810485) with SLE susceptibility, as well as with mRNA expression and soluble CD40 (sCD40) levels.

Methods

The study included 293 patients with SLE and 294 control subjects (CS). Genotyping was performed by PCR‐RFLP method. CD40 mRNA expression was determined by quantitative real‐time PCR, and ELISA quantified sCD40 levels.

Results

The CD40 polymorphisms −1 C > T and 6,048 G > T were associated with SLE susceptibility. There was no difference between CD40 mRNA expression and CD40 polymorphisms. The sCD40 levels were lower in SLE patients with TT haplotype, whereas higher sCD40 levels were associated with damage and impaired renal function according to SLICC and KDIGO. The sCD40 levels were negatively correlated with eGFR.

Conclusion

The CD40 gene polymorphisms increase the risk of SLE in the western Mexican population. The sCD40 levels are associated with −1 C > T polymorphism and chronic kidney disease.

Analysis of Genetic Variation in CD40 and CD40L: Relationship with mRNA Relative Expression and Soluble Proteins in Acute Coronary Syndrome

Acute coronary syndrome (ACS) can be triggered by the presence of inflammatory factors which promote the activation of immune cells by costimulatory molecules such as CD40 and its ligand CD40L. Environmental and genetic factors are involved in the etiology of the ACS. The aim of this study was to explore the gene and protein expression associated with CD40 and CD40L genetic variants in ACS patients from the western Mexican population. A total of 620 individuals from western Mexico were recruited: 320 ACS patients and 300 individuals without a history of ischemic cardiopathy were evaluated. The genotype was determined using TaqMan SNP genotyping assays. CD40 and CD40L expressions at the mRNA level were quantified using TaqMan Gene Expression Assays. Soluble protein isoforms were measured by enzyme-linked immunosorbent assay. We did not find evidence of association between CD40 (rs1883832, rs4810485, and rs11086998) and CD40L (rs3092952 and rs3092920) genetic variants and susceptibility to ACS, although rs1883832 and rs4810485 were significantly associated with high sCD40 plasma levels. Plasma levels of sCD40L can be affected by gender and the clinical spectrum of acute coronary syndrome. Our results do not suggest a functional role of CD40 and CD40L genetic variants in ACS. However, they could reflect the inflammatory process and platelet activation in ACS patients, even when they are under pharmacological therapy. Due to the important roles of the CD40-CD40L system in the pathogenesis of ACS, longitudinal studies are required to determine if soluble levels of CD40 and CD40L could be clinically useful markers of a recurrent cardiovascular event after an ACS.

The 3'-UTR (CA)n microsatellite on CD40LG gene as a possible genetic marker for rheumatoid arthritis in Mexican population: impact on CD40LG mRNA expression

The objective of this study was to determine the association of the CD40LG 3'-UTR (CA)n microsatellite with rheumatoid arthritis (RA) and CD40LG mRNA levels in females from western Mexico. A case-control study with 219 RA patients and 175 control subjects (CS) was conducted. Genotyping was performed by polymerase chain reaction (PCR), X ² test was used to compare genotype and allele frequencies, and odds ratios and 95% confidence intervals were calculated to evaluate the association between RA and the microsatellite. CD40LG mRNA expression was assessed by real-time quantitative PCR. For comparisons between groups, Kruskal-Wallis or Mann-Whitney U tests for non-parametric data and ANOVA test for parametric data were performed. Among the 13 different alleles identified, CA₂₅ was the most represented (45.4% RA and 46.3% CS). Stratification according to CA repeats as <CA₂₅, CA₂₅, and >CA₂₅ showed a tendency towards a higher frequency of >CA₂₅ alleles in RA patients (29%) compared to CS (23.4%). There was no association between any genotype and the clinical parameters of RA patients. According to the 2^-∆∆Cq method, CD40LG mRNA expression in RA patients was 4.5-fold higher compared to CS; this difference was significant when assessed by the 2^-∆Cq method (p = 0.028). Compared to carriers of the CA₂₅/CA₂₅ genotype, CS carrying the <CA₂₅/<CA₂₅ genotypes showed greater CD40LG mRNA expression (9.97-fold), unlike RA patients, where expression was 2.55-fold higher for >CA₂₅/>CA₂₅ carriers. The 3'-UTR CD40LG (CA)n microsatellite is not a genetic marker for RA in western Mexican population; however, results suggest that it plays a role in the CD40LG mRNA expression.

Association between CD40 rs1883832 and immune-related diseases susceptibility: A meta-analysis

Background/objective

It has been reported that CD40 rs1883832 might be associated with immune-related diseases susceptibility. Owing to mixed and inconclusive results, we conducted a meta-analysis of case–control studies to summarize and clarify this association.

Methods/main results

A systematic search of studies on the association between CD40 rs1883832 and immune-related diseases susceptibility was conducted in databases. Odds ratios and 95% confidence intervals were used to pool the effect size. 40 articles were included in our meta-analysis.

Conclusions

CD40 rs1883832 is associated with decreased risk of Graves’ disease, especially in Asian; CD40 rs1883832 is associated with increased risk of multiple sclerosis; CD40 -1C>T (rs1883832) is not associated with the susceptibility of Hashimoto's thyroiditis, systemic sclerosis or Asthma; there is insufficient data to fully confirm the association between CD40 rs1883832 and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Behçet's disease (BD), myasthenia gravis (MG), Crohn's disease (CD), ulcerative colitis (UC), Sarcoidosis, Fuch uveitis syndrome (FUS), Vogt-Koyanagi-Harada syndrome (VKH), Kawasaki disease (KD), giant cell arteritis (GCA) or Immune thrombocytopenia (ITP).

CD40L and Its Receptors in Atherothrombosis-An Update

CD40L (CD154), a member of the tumor necrosis factor superfamily, is a co-stimulatory molecule that was first discovered on activated T cells. Beyond its fundamental role in adaptive immunity-ligation of CD40L to its receptor CD40 is a prerequisite for B cell activation and antibody production-evidence from more than two decades has expanded our understanding of CD40L as a powerful modulator of inflammatory pathways. Although inhibition of CD40L with neutralizing antibodies has induced life-threatening side effects in clinical trials, the discovery of cell-specific effects and novel receptors with distinct functional consequences has opened a new path for therapies that specifically target detrimental properties of CD40L. Here, we carefully evaluate the signaling network of CD40L by gene enrichment analysis and its cell-specific expression, and thoroughly discuss its role in cardiovascular pathologies with a specific emphasis on atherosclerotic and thrombotic disease.

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.

Investigation of CD40 gene rs4810485 and rs1883832 mutations in patients with recurrent aphthous stomatitis

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a common painful disorder affecting oral health, mucosa and overall quality of life. The etiopathogenesis of RAS remains unclear. RAS shows a large genetic diversity among the patients. In present study, we investigated whether CD40 gene rs4810485 and rs1883832 are associated with RAS and its clinical findings in Turkish patients.

MATERIALS AND METHODS

Genomic DNA obtained from 387 individuals (160 patients with RAS and 227 healthy controls) were used in the study. CD40 gene rs4810485 and rs1883832 mutations were determined by using polymerase chain reaction with the specific primers.

RESULTS

There was no statistically significant difference between the groups with respect to genotype and allele distribution (p>0.05, OR 0.94, 95% CI 0.70-1.28, OR 1.01 95% CI 0.75-1.37, respectively). Additionally, there was no statistically significant difference in the combined genotype analysis of CD40 gene rs4810485 and rs1883832 mutations (p>0.05).

CONCLUSIONS

According to our results, we found that CD40 gene mutations are not associated with RAS. We are convinced that CD40 gene mutations do not predispose to develop RAS in Turkish population. To our knowledge, this is the first study regarding CD40 gene rs4810485 and rs1883832 mutations investigated in RAS patients.

Rheumatoid Arthritis and Coronary Artery Disease: Genetic Analyses Do Not Support a Causal Relation

OBJECTIVE

Inflammatory diseases, specifically rheumatoid arthritis (RA), are assumed to increase the risk of coronary artery disease (CAD). More recently, multiple single-nucleotide polymorphisms (SNP) associated with RA risk were identified. If causal mechanisms affecting risks of RA and CAD are overlapping, risk alleles for RA might also increase the risk of CAD.

METHODS

Sixty-one SNP associating with RA in genome-wide significant analyses were tested for association with CAD in CARDIoGRAM (Coronary ARtery DIsease Genome wide Replication and Meta-analysis), a metaanalysis including genome-wide association data (22,233 CAD cases, 64,762 controls). In parallel, a set of SNP being associated with low-density lipoprotein cholesterol (LDL-C) was tested as a positive control.

RESULTS

Twenty-nine RA-associated SNP displayed a directionality-consistent association with CAD (OR range 1.002-1.073), whereas 32 RA-associated SNP were not associated with CAD (OR range 0.96-0.99 per RA risk-increasing allele). The proportion (48%) of directionality-consistent associated SNP equaled the proportion expected by chance (50%, p = 0.09). Of only 5 RA-associated SNP showing p values for CAD < 0.05, 4 loci (C5orf30, IL-6R, PTPN22, and RAD51B) showed directionality-consistent effects on CAD, and 1 (rs10774624, locus SH2B3) reached study-wide significance (p = 7.29E-06). By contrast, and as a proof of concept, 46 (74%) out of 62 LDL-C-associated SNP displayed a directionality-consistent association with CAD, a proportion that was significantly different from 50% (p = 5.9E-05).

CONCLUSION

We found no evidence that RA-associated SNP as a group are associated with CAD. Even though we were not able to study potential effects of all genetic variants individually, shared nongenetic factors may more plausibly explain the observed coincidence of the 2 conditions.

Aortic aneurysm associated with rheumatoid arthritis: a population-based cross-sectional study

There is substantial evidence that aortic aneurysm (AA) may be a manifestation of several systemic rheumatic disorders. However, only several studies have assessed the association between rheumatoid arthritis (RA) and AA. The aim of this study was to evaluate the incidence of AA in RA patients in a case-control study. A retrospective case-control study was performed utilizing the database of Clalit Health Services (CHS), a large healthcare provider organization in Israel. Data available from the CHS database included age, sex, socioeconomic status (SES), and diagnoses of chronic diseases, including AA. Patients over the age of 20 years who were diagnosed with RA ("cases") were compared with a sample of age- and gender-matched enrollees without RA ("controls") regarding the prevalence of AA. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The study included 11,782 RA patients and 57,973 age- and gender-matched controls. The proportion of AA was significantly higher in RA patients (0.72 %) compared to the control group 0.49 % (odds ratio (OR) 1.48, 95 %; confidence interval (CI) 1.15-1.88; p = 0.002). A multivariate analysis that evaluated covariates associated with AA revealed an independent association of AA and RA after adjustment for different factors including age, gender, SES, and smoking status (OR 1.406, 95 %; CI 1.094-1.789; p = 0.006). Our study has demonstrated that AA is more prevalent in patients with RA in comparison with general population. Future large randomized studies are important to identify cardiovascular- and disease-related risk factors for AA formation in RA patients.

Levels of human platelet-derived soluble CD40 ligand depend on haplotypes of CD40LG-CD40-ITGA2

Increased circulating soluble CD40 ligand (sCD40L) is commonly associated with inflammatory disorders. We aimed to investigate whether gene polymorphisms in CD40LG, CD40 and ITGA2 are associated with a propensity to secrete sCD40L; thus, we examined this issue at the level of human platelets, the principal source of sCD40L. We performed single polymorphism and haplotype analyses to test for the effect of twelve polymorphisms across the CD40LG, CD40 and ITGA2 genes in blood donors. ITGA2 presented a positive association with rs1126643, with a significant modification in sCD40L secretion (carriers of C allele, P = 0.02), unlike the investigated CD40LG and CD40 polymorphisms. One CD40LG haplotype (TGGC) showing rs975379 (C/T), rs3092952 (A/G), rs3092933 (A/G) and rs3092929 (A/C) was associated with increased sCD40L levels (1.906 μg/L (95% CI: 1.060 to 2.751); P = 0.000009). The sCD40L level was associated with the inter-chromosomal CD40LG/CD40/ITGA2 haplotype (ATC), displaying rs3092952 (A/G), rs1883832 (C/T) and rs1126643 (C/T), with increased sCD40L levels (P = 0.0135). Our results help to decipher the genetic role of CD40LG, CD40 and ITGA2 with regard to sCD40L levels found in platelet components. Given the crucial role of sCD40L, this haplotype study in a transfusion model may be helpful to further determine the role of haplotypes in inflammatory clinical settings.

Development of a highly resolutive method, using a double quadruplex tetra-primer-ARMS-PCR coupled with capillary electrophoresis to study CD40LG polymorphisms

Polymorphisms in the CD40 ligand gene (CD40LG) are associated with various immunological disorders such as tumors, autoimmune and infectious diseases. The aim of this study was to develop a highly optimized double quadruplex tetra-primer amplification refractory mutation system PCR (double quadruplex T-ARMS-PCR) coupled with capillary electrophoresis to allow genotyping of eight relevant candidate CD40LG SNPs and to establish haplotypes. After conducting the double quadruplex T-ARMS-PCR, the genotypes obtained through agarose electrophoresis were compared with those obtained through capillary electrophoresis. This strategy was applied to analyze the genetic patterns of CD40LG in two distinct cohorts of blood donors (211 French and 274 Tunisian). The T-ARMS-PCR method was rapid, inexpensive, reproducible and reliable for SNP determination. Regarding the separation technique, capillary electrophoresis allows traceable and semi-automated analysis while agarose electrophoresis remains a cost-effective technique that does not require specialized or costly equipment. Using these methods, we identified significantly different genetic heterogeneity between the two investigated populations (p ≤ 0.0001) and we also extensively characterized their haplotypes. The obtained genotype distribution and the optimized quadruplex T-ARMS-PCR technique coupled with capillary electrophoresis provides valuable information for studying pathologic inflammation leading to various diseases in which CD40LG might be a candidate gene.

The effect of disease duration and disease activity on the risk of cardiovascular disease in rheumatoid arthritis patients

OBJECTIVE

Disease duration and disease activity may be associated with an increased risk of cardiovascular disease (CVD) in rheumatoid arthritis (RA). The objectives of this study were to investigate (1) the relationship between duration of inflammation and the development of CVD in RA patients and (2) the relationship between RA disease activity over time and CVD in patients with RA.

METHODS

RA patients with a follow-up of ≥6 months in the Nijmegen early RA cohort without prior CVD were included. Disease activity over time was calculated using the time-averaged  28 joint disease activity score (DAS28) for each patient. Kaplan-Meier survival analysis and Cox proportional hazards regression were used for the analyses.

RESULTS

During follow-up of the 855 patients that were included, 154 CV events occurred. The course of hazards over time did not indicate a change in the risk of CVD over the course of RA (disease duration), which is also reflected by the absence of a deflection in the survival curves. The survival distributions did not differ between patients with a disease duration of <10 years or >10 years (Log-rank test: p=0.82). Time-averaged DAS28 was significantly associated with CVD (p=0.002) after correction for confounders.

CONCLUSIONS

Disease duration does not appear to independently affect the risk of CVD. The risk of CVD in RA patients was not increased after 10 years of disease duration compared with the first 10 years. Disease activity over time may contribute to the risk of CVD.

Associations between the functional CD40 rs4810485 G/T polymorphism and susceptibility to rheumatoid arthritis and systemic lupus erythematosus: a meta-analysis

Objective

The aim of this study was to determine whether the functional CD40 rs4810485 G/T polymorphism is associated with susceptibility to rheumatoid arthritis (RA) or with susceptibility to systemic lupus erythematosus (SLE).

Methods

A series of meta-analyses were conducted to test for association between the CD40 rs4810485 G/T polymorphism and RA or SLE.

Results

A total of 21 comparisons involving 15,095 patients and 27,050 controls for RA, and 1353 patients and 2342 controls for SLE were considered. Meta-analysis showed a significant association between the CD40 rs4810485 T allele and RA in all subjects (odds ratio (OR) 0.890, 95% confidence interval (CI) 0.846–0.936, p = 5.5 × 10−7). After stratification by ethnicity, the CD40 T allele was found to be significantly associated with RA in Europeans (OR 0.879, 95% CI 0.848–0.901, p = 3.0 × 10−9). A similar pattern of association was observed between the CD40 T allele and RA when the analysis was performed using the recessive, dominant, and additive models. Meta-analysis also showed a significant association between the CD40 polymorphism and SLE in Europeans (OR for the T allele 0.715, 95% CI 0.641–0.832, p = 1.4 × 10−6).

Conclusions

Our meta-analyses confirm that the CD40 rs4810485 G/T polymorphism is associated with susceptibility to RA and SLE in Europeans.

Genetic risk scores and number of autoantibodies in patients with rheumatoid arthritis

OBJECTIVE

Certain HLA-DRB1 alleles and single-nucleotide polymorphisms (SNPs) are associated with rheumatoid arthritis (RA). Our objective was to examine the combined effect of these associated variants, calculated as a cumulative genetic risk score (GRS) on RA predisposition, as well as the number of autoantibodies (none, one or two present).

METHOD

We calculated four GRSs in 4956 patients and 4983 controls from four European countries. All four scores contained data on 22 non-HLA-risk SNPs, and three scores also contained HLA-DRB1 genotypes but had different HLA typing resolution. Most patients had data on both rheumatoid factor (RF) and anti-citrullinated proteins antibodies (ACPA). The GRSs were standardised (std.GRS) to account for population heterogeneity. Discrimination between patients and controls was examined by receiveroperating characteristics curves, and the four std.GRSs were compared across subgroups according to autoantibody status.

RESULTS

The std.GRS improved its discriminatory ability between patients and controls when HLA-DRB1 data of higher resolution were added to the combined score. Patients had higher mean std.GRS than controls (p=7.9×10(-156)), and this score was significantly higher in patients with autoantibodies (shown for both RF and ACPA). Mean std.GRS was also higher in those with two versus one autoantibody (p=3.7×10(-23)) but was similar in patients without autoantibodies and controls (p=0.12).

CONCLUSIONS

The GRS was associated with the number of autoantibodies and to both RF and ACPA positivity. ACPA play a more important role than RF with regards to the genetic risk profile, but stratification of patients according to both RF and ACPA may optimise future genetic studies.

Lack of association between JAK3 gene polymorphisms and cardiovascular disease in Spanish patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a polygenic disease associated with accelerated atherosclerosis and increased cardiovascular (CV) mortality. JAK/STAT signalling pathway is involved in autoimmune diseases and in the atherosclerotic process. JAK3 is a highly promising target for immunomodulatory drugs and polymorphisms in JAK3 gene have been associated with CV events in incident dialysis patients. Therefore, the aim of this study was to assess the potential role of JAK3 polymorphisms in the development of CV disease in patients with RA. 2136 Spanish RA patients were genotyped for the rs3212780 and rs3212752 JAK3 gene polymorphisms by TaqMan assays. Subclinical atherosclerosis was evaluated in 539 of these patients by carotid ultrasonography (US). No statistically significant differences were found when each polymorphism was assessed according to carotid intima-media thickness values and presence/absence of carotid plaques in RA, after adjusting the results for potential confounders. Moreover, no significant differences were obtained when RA patients were stratified according to the presence/absence of CV events after adjusting for potential confounders. In conclusion, our results do not confirm association between JAK3 polymorphisms and CV disease in RA.

Associations of rs4810485 and rs1883832 polymorphisms of CD40 gene with susceptibility and clinical findings of Behçet's disease

There are evidences that besides geographic tendency, interactions between genetic and environmental factors play an essential role in the pathogenesis of Behçet's disease (BD). In this study, we have evaluated the associations between rs4810485 and rs1883832 single nucleotide polymorphism (SNP)s of CD40 gene with the susceptibility and clinical findings of BD. Two hundred and eighty-five patients with BD and 225 age-matched healthy controls were enrolled in this study. The clinical findings of patients were noted. The distributions of genotypes, alleles, combined genotypes and haplotypes of these two SNPs in BD patients were compared with those in healthy controls. In further evaluation, we evaluated the patients with and without any of clinical findings with regarding to distribution of genotypes and alleles of these two SNPs. There was no significant difference concerning frequencies of genotypes, alleles, combined genotypes and haplotypes of rs4810485 and rs1883832 between patients and controls (p > 0.05 for all). Frequency of GT genotype of CD40 rs4810485 polymorphism was found to be significantly higher in patients with skin lesions (p < 0.05, OR 1.65, 95 % CI 1.02-2.64). Also, we have found significantly higher frequencies of CC genotype and C allele of CD40 rs1883832 polymorphism in patients with genital ulcers (p < 0.05 for both, OR 2.30, 95 % CI 1.07-4.94 and OR 1.78, 95 % CI 1.06-2.97, respectively). However, these significances were disappeared after Bonferroni correction. We suggest that differences in the expression levels of CD40 because of different genotypes of these two SNPs may take part in the development of skin lesions or genital ulcers in patients with BD.

Lack of association between CD40 polymorphisms and acute rejection in German liver transplant recipients

CD40 and its ligand, CD154, are major costimulatory molecules whose interactions are important in alloreactive transplant rejection. The aim of this study was to examine the association of CD40 polymorphisms with the susceptibility to acute rejection episodes in liver transplantation. In total, 112 liver transplant recipients with biopsy proven acute rejections (BPAR), 97 without BPAR (WBPAR), and 112 healthy control individuals were enrolled in the study. Two single nucleotide polymorphisms (SNPs) of CD40 gene (rs1883832 and rs4810485) were genotyped by polymerase chain reaction-allele specific restriction enzyme analysis (PCR-ASRA). Both SNPs has been tested for a recessive and a dominant model. No significant differences were found in the genotype and allele frequencies of the SNPs rs1883832 and rs4810485 between BPAR liver recipients and WBPAR recipients. Our results do not suggest an important role of tested CD40 SNPs in the susceptibility to acute liver transplant rejection in a Caucasian population.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Interferon regulatory factor 5 genetic variants are associated with cardiovascular disease in patients with rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a complex polygenic inflammatory disease associated with accelerated atherosclerosis and increased cardiovascular (CV) disease risk. Interferon regulatory factor 5 (IRF5) is a regulator of type I interferon induction. Recently, researchers have described an association between multiple single-nucleotide polymorphisms of the IRF5 gene and some rheumatic disorders. In this study, we aimed to evaluate whether three different haplotype blocks within the IRF5 locus which have been shown to alter the protein function are involved in the risk of CV events occurring in Spanish RA patients.

METHODS

Three IRF5 polymorphisms (rs2004640, rs2070197 and rs10954213) representative of each haplotype group were genotyped by performing TaqMan assays using a 7900HT Fast Real-Time PCR System with tissue from a total of 2,137 Spanish patients diagnosed with RA. Among them, 390 (18.2%) had experienced CV events. The relationship of IRF5 genotypes and haplotypes to CV events was tested using Cox regression.

RESULTS

Male sex, age at RA diagnosis and most traditional risk factors (hypertension, dyslipidemia and smoking habit) were associated with increased risk for CV events in the RA population. Interestingly, a protective effect of both IRF5 rs2004640 GG and IRF5 rs10954213 GG genotypes against the risk for CV events after adjusting the results for sex, age at RA diagnosis and traditional CV disease risk factors was observed (hazard ratio (HR) = 0.6, 95% confidence interval (CI) = 0.38 to 0.92, P = 0.02; and HR = 0.58, 95% CI = 0.36 to 0.95, P = 0.03, respectively). Moreover, we detected a protective effect of the GTG haplotype against the risk for CV events after adjusting the results for potential confounding factors (HR = 0.72, 95% CI = 0.56 to 0.93, P = 0.012).

CONCLUSIONS

Our results reveal that IRF5 gene variants are associated with risk of CV events in patients with RA.

The 11q23.3 genomic region-rs964184-is associated with cardiovascular disease in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory disease associated with high risk of cardiovascular (CV) events. Recently, the rs964184 polymorphism has been associated with coronary artery disease in nonrheumatic Caucasian individuals. 2160 Spanish RA patients were genotyped for the rs964184 polymorphism. Sex, age at diagnosis and traditional CV risk factors (diabetes mellitus, dyslipidemia and smoking habit) were associated with increased risk of CV events. Interestingly, RA patients carrying the rs964184 GG genotype had significantly higher risk of CV events than those with CC genotype [hazard ratio (HR) = 2.91, 95% confidence interval (CI): 1.36-6.26, P = 0.006] after adjusting the results for sex, age at diagnosis and traditional CV risk factors. Our results indicate that rs964184 polymorphism is associated with CV disease in RA.

Investigation of gene-gene interactions between CD40 and CD40L in Polish multiple sclerosis patients

CD40-CD40L interaction is necessary for the activation of both humoral and cellular immune response and has been suggested to play a role in the pathogenesis of multiple sclerosis (MS). Therefore, we analyzed the combined influence of the CD40 and CD40L variants on MS susceptibility and progression on well-defined Polish population. Our investigation revealed that CT individuals in rs1883832 locus of CD40 possessed almost 1.5-fold higher risk for MS than CC individuals (OR = 1.44; 95%CI = 1.03-2.1; p = 0.032), while this risk for TT individuals was almost 2.5-fold higher (OR = 2.36; 95%CI = 1.19-4.78; p = 0.014). Moreover, for the first time, we observed the association of CD40 gene with MS development and progression. We observed that for the rs1883832CC individuals the age at diagnosis was on average 2 years lower than for the rs1883832CT and rs1883832TT individuals (CI95% = -3.69-(-0.29); p = 0.023). Additionally, we detected that individuals with TT and CT genotypes showed lower risk of developing secondary progressive course in comparison to those with CC genotype. For rs1883832TT individuals this risk was 4-fold lower (HR = 0.24; CI95% = 0.10-0.53; p = 0.00062). Despite the fact that CD40-CD40L pathway plays a key role in development of autoimmune diseases, we were not able to detect gene-gene interactions between CD40 and CD40L polymorphisms associated with multiple sclerosis.

The SNP rs1883832 in CD40 gene and risk of atherosclerosis in Chinese population: a meta-analysis

Background

The complications of atherosclerosis such as coronary and cerebrovascular disease, are the most prevalent causes of mortality and morbidity worldwide. A single nucleotide polymorphism (SNP) rs1883832 (-1C/T) in CD40 gene has been recently suggested to contribute to the susceptibility to atherosclerosis in Chinese population; however, previous genetic association studies yielded inconsistent results.

Methods

A meta-analysis of eligible studies reporting the association between rs1883832 and atherosclerosis in Chinese population was carried out.

Results

Pooling 7 eligible case-control studies involving 2129 patients and 1895 controls demonstrated a significant association between rs1883832 and atherosclerosis under dominant model [odds ratio (OR) = 1.631, 95% confidence interval [CI] [1.176, 2.260] in Chinese population with evident heterogeneity. Meta-regression analysis indicated that the heterogeneity could be completely explained by disease category. In subgroup analysis, rs1883832 conferred ORs of 2.866 (C/C versus T/T, 95%CI [2.203, 3.729]) and 1.680 (C/T versus T/T, 95%CI [1.352, 2.086]) for coronary artery disease (CAD) under co-dominant model without heterogeneity. Similar results were obtained for acute coronary syndrome (ACS) (C/C versus T/T, 3.674, 95%CI [2.638, 5.116]; C/T versus T/T, 1.981, 95%CI [1.483, 2.646]). The other genetic models including dominant, recessive and additive models, yielded consistent results without heterogeneity for CAD and ACS, respectively. However, a protective role was found for C allele in ischemic stroke (IS) under recessive model (0.582, 95%CI [0.393, 0.864]) and additive model (0.785, 95%CI [0.679, 0.909]) with reduced heterogeneity.

Conclusions

This meta-analysis provided evidence of association of rs1883832 C allele with an overall increased risk of atherosclerosis but distinct effect of C allele on CAD (including ACS) and IS in Chinese population, respectively.

Immune checkpoint receptors in regulating immune reactivity in rheumatic disease

Immune checkpoint regulators are critical modulators of the immune system, allowing the initiation of a productive immune response and preventing the onset of autoimmunity. Co-inhibitory and co-stimulatory immune checkpoint receptors are required for full T-cell activation and effector functions such as the production of cytokines. In autoimmune rheumatic diseases, impaired tolerance leads to the development of diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjogren's syndrome. Targeting the pathways of the inhibitory immune checkpoint molecules CD152 (cytotoxic T lymphocyte antigen-4) and CD279 (programmed death-1) in cancer shows robust anti-tumor responses and tumor regression. This observation suggests that, in autoimmune diseases, the converse strategy of engaging these molecules may alleviate inflammation owing to the success of abatacept (CD152-Ig) in rheumatoid arthritis patients. We review the preclinical and clinical developments in targeting immune checkpoint regulators in rheumatic disease.

SMAD3 rs17228212 gene polymorphism is associated with reduced risk to cerebrovascular accidents and subclinical atherosclerosis in anti-CCP negative Spanish rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a complex polygenic inflammatory disease associated with accelerated atherosclerosis and increased risk of cardiovascular (CV) disease. Previous genome-wide association studies have described SMAD3 rs17228212 polymorphism as an important signal associated with CV events. The aim of the present study was to evaluate for the first time the relationship between this gene polymorphism and the susceptibility to CV manifestations and its potential association with the presence of subclinical atherosclerosis assessed by the evaluation of carotid intima-media thickness (cIMT) in patients with RA.

Integrative analyses for functional mechanisms underlying associations for rheumatoid arthritis

OBJECTIVE

Extensive association analyses including genome-wide association studies (GWAS) and powerful metaanalysis studies have identified a long list of loci associated with rheumatoid arthritis (RA) in very large populations, but most of them established statistical associations of genetic markers and RA only at the DNA level, without supporting evidence of functional relevance. Our study serves as a trial to detect the functional mechanisms underlying associations for RA by searching publicly available datasets and results.

METHODS

Based on publicly available datasets and results, we performed integrative analyses (gene relationships across implicated loci analysis, differential gene expression analysis, and functional annotation clustering analysis) and combined them with the expression quantitative trait locus (eQTL) results to dissect functional mechanisms underlying the associations for RA.

RESULTS

By searching 2 GWAS, Integrator and PheGenI, we selected 98 RA association results (p < 10(-5)). Among these associations, we found that 8 single-nucleotide polymorphisms (SNP; rs1600249, rs2736340, rs3093023, rs3093024, rs4810485, rs615672, rs660895, and rs9272219) serve as cis-effect regulators of the corresponding eQTL genes (BLK and CD4 in non-HLA region; CCR6, HLA-DQA1, and HLA-DQB1 in HLA region) that also were differentially expressed in RA-related cell groups. These 5 genes are closely related with immune response in function.

CONCLUSION

Our results showed the functional mechanisms underlying the associations of 8 SNP and the corresponding genes. This study is an example of mining publicly available datasets and results in validation of significant disease-association results. Using public data resources for integrative analyses may provide insights into the molecular genetic mechanisms underlying human diseases.