Caucasian Rheumatoid Arthritis Patients Research Articles

First China Approved Rituximab Biosimilar HLX01: Pharmacokinetics, Safety and Efficacy Comparison to Reference Rituximab in the Phase 3 Diffuse Large B-Cell Lymphoma Study

Background In February 2019, the National Medicinal Products Administration (NMPA) approved the first China-manufactured rituximab (RTX) biosimilar, HLX01, for the treatment of non-Hodgkin's lymphoma in accordance to the development of biosimilar guidelines with stepwise approach demonstrating bioequivalence. HLX01 was also developed as a novel drug for rheumatoid arthritis (RA) since the indication has not been approved in China. Studying pharmacokinetics (PK) in healthy volunteers as the most sensitive population is not ethically acceptable due to the safety concerns associated with rituximab. The NMPA approval was based on a comprehensive data package of extensive analytical characterization, non-clinical studies, clinical trials and the population PK (PopPK) model. Here, we report the Phase 3 confirmatory study aimed to establish equivalence in safety and efficacy of HLX01 and RTX in patients with diffuse large B-cell lymphoma (DLBCL) and the PopPK model derived from the PK data of HLX01 and RTX in RA compared the PK data in DLBCL and the Caucasian RTX data in RA. Methods In this multicenter, randomized, double-blind, parallel active-controlled, Phase 3 study (NCT02787239), treatment-naïve adults aged 18-80 years with histologically confirmed CD20+ DLBCL were treated with cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) and randomly assigned at 1:1 ratio to co-administer with HLX01 (H-CHOP) or RTX (R-CHOP) every 21 days cycle treatment. The primary efficacy endpoint was the best overall response rate (ORR) for HLX01 and RTX over 6-cycle therapy. The therapeutic equivalence was concluded if 95% confidence interval (CI) of the difference in best ORRs between the two treatments fell within the pre-specified range of ±12%. Additional endpoints included long-term efficacy outcomes, safety and immunogenicity profiles and sparse PK samplings for peak and trough levels comparison. The PopPK model was developed from the randomized, double-blind PK study (NCT03355872) of HLX01 and RTX in 196 patients with moderately to severely active RA (serum sample=4289) using non-linear mixed-effect modeling (NONMEM®) and the first-order estimation with interaction (FOCEI) method. The PK and PK-pharmacodynamic relationship being characterized with various covariates were tested on forward addition (p<0·01) / backward elimination (p<0·001). After the final model being examined with Bayesian bootstrapping, visual predictive check (VPC) and 1000 simulations from the observed covariates, external validations were tested using the Phase 3 PK data in 110 patients with DLBCL and comparing the Chinese data with other races by simulations from several published PK data in Caucasian RA patients. Results The best ORRs [95% CI] within 6 cycles therapy were 94·1% [89·77%, 97·04%] in H-CHOP and 92·8% [88·19%, 96·00%] in R-CHOP with the ORR difference (1·4% [−3·59%, 6·32%], p=0·608) fell in the pre-specified equivalent margin. Long-term efficacy and safety profiles, including the incidence of treatment-emergent adverse events (p=1·000) and serious adverse events (p=0·752), were similar in two treatment groups (Table 1). The best model fit for the PopPK was a two-compartment model with first-order elimination. The estimated clearance (CL), central volume (Vc), peripheral-compartment volume and clearance-of-distribution from the central-to-peripheral-compartment were 27·32%, 16·56%, 21·61%, and 40·79%, respectively. The correlation between CL and Vc was 0.02239. The observed concentrations and simulations for the corresponding model predicted all subjects in the dataset with no significant difference in area under the curve from zero to infinity between two clinical studies of HLX01 and RTX. The PK results were also similar to the existing model in Caucasian. Conclusion HLX01 demonstrated equivalent safety and efficacy to the reference RTX with no clinically meaningful differences in CD20+ DLBCL. The PopPK model successfully proved the PK similarity between HLX01 and RTX in patients with RA or DLBCL with no racial differences. Based on the totality of evidence with the results from this Phase 3 study and PopPK modeling, China NMPA approved HLX01 as the first China RTX biosimilar with the potential to provide alternative treatment option for patients. To the best of our knowledge, we are the first reporting the establishment of biosimilarity with RTX in DLBCL patient population. Disclosures Zhao: Certara Strategic Consulting China: Employment. Hong:Shanghai Henlius Biotech, Inc.: Employment. Ma:Shanghai Henlius Biotech, Inc.: Employment. Cheng:Shanghai Henlius Biotech, Inc.: Employment. Ting:Shanghai Henlius Biotech, Inc.: Employment. Li:Shanghai Henlius Biotech, Inc.: Employment. Jiang:Shanghai Henlius Biotech, Inc.: Employment. Liu:Shanghai Henlius Biotech, Inc.: Employment. Liu:Shanghai Henlius Biotech, Inc.: Employment. Zhang:Shanghai Henlius Biotech, Inc.: Employment. Chai:Shanghai Henlius Biotech, Inc.: Employment. Yao:Shanghai Henlius Biotech, Inc.: Employment. Luk:Shanghai Henlius Biotech, Inc.: Employment.

IL-12B Gene Polymorphisms and IL-12 p70 Serum Levels Among Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is one of the autoimmune diseases, where different polymorphisms in cytokine genes play a pathogenic role. IL-12 is now recognized as a critical cytokine in terms of regulating the balance between Th1 and Th2 cells. We investigated the role of single nucleotide polymorphisms (SNPs) (rs3212227 (A/C) and rs17860508 (CTCTAA/GC)) of the IL-12B gene in the genetic susceptibility to RA and in the severity of the disease. Six hundred and thirty-four Caucasian RA patients and 341 healthy matched controls were studied using PCR-RFLP method and high-resolution melting analysis. Concentration of IL-12 cytokine level in serum was evaluated using ELISA. The genotype frequency did not deviate from HWE in each examined group. Frequencies of the rs3212227 CC genotype were statistically higher in patients with RA compared with the healthy control group in both codominant and recessive models (P=0.037; P=0.04, respectively). The frequency of rs3212227 C allele also showed similar tendency (P=0.07). IL-12 level in serum was significantly higher in RA group compared with control (P<0.0001). We observed that increased IL-12 serum level was correlated with higher number of tender and swollen joints, ExRA presence and higher levels of haemoglobin, CRP and PLT. Also higher IL-12 level in serum was observed within RA patients with hypertension. Present findings indicated that IL-12p40+1188A/C polymorphism as well as IL-12p70 protein levels may be associated with RA in the Polish population.

The plausible association of MTHFR and ADORA2A polymorphisms with nodules in rheumatoid arthritis patients treated with methotrexate.

The treatment of rheumatoid arthritis (RA) patients with methotrexate (MTX) is linked to the development or progression of rheumatoid nodules. The aim of this study was to determine whether folate and adenosine pathways-related single nucleotide polymorphisms might be predictive of increased nodule formation in RA patients treated with oral MTX. A total of 185 Caucasian RA patients were enrolled in this cross-sectional study, all of whom fulfilled the 1987 RA criteria of the American College of Rheumatology; each patient had a history of MTX treatment. A higher frequency of the MTHFR 1298AA genotype was found in 17 (70.8%) of 24 patients with general nodules [odds ratio (OR)=3.08, 95% confidence interval (CI): 1.20-7.69] and in 14 (73.7%) of 19 patients who developed nodules during MTX treatment (OR=3.55, 95% CI: 1.22-10.32). In contrast, a negative association with nodules during MTX treatment (OR=0.29, 95% CI: 0.08-1.10) was found for 19 (79.2%) patients with the TT genotype (rs2298383) in the adenosine A2a receptor gene (ADORA2A). However, the significance did not remain upon correction for multiple testing. The combination of MTHFR 1298AA along with ADORA2A rs2298383 CC or CT genotypes occurring in one-third of RA patients showed a higher frequency of general nodules 15/59 (25.4%) as well as developing nodules during MTX treatment 13/59 (22.0%) in comparison with the overall studied group: 24/185 (13.0%) and 19/185 (10.3%), respectively. This exploratory study indicates for the first time a plausible association of adenosine and folate pathways single nucleotide polymorphisms in nodules' etiopathogenesis.

Association of the ATIC 347 C/G polymorphism with responsiveness to and toxicity of methotrexate in rheumatoid arthritis: a meta-analysis.

This study investigated whether the 5-aminoimidazole-4-carboxamide ribonucleotide transformylase gene (ATIC) 347 C/G polymorphism can predict the response to or toxicity of methotrexate (MTX) in patients with rheumatoid arthritis (RA). We conducted a meta-analysis of studies on the association between ATIC 347 C/G polymorphism and non-responsiveness to or toxicity of MTX in RA patients, using PUBMED, EMBASE, and COCHRANE. Nine comparative studies from 6 articles including 1056 RA patients met our inclusion criteria. This final group of studies comprised 5 studies on response to MTX and 4 on toxicity of MTX in RA patients in relation to the ATIC 347 C/G polymorphism status. Meta-analysis showed association between the ATIC 347 GG+GC genotype and non-response to MTX therapy (OR=1.572, 95% CI 1.146-2.156, p=0.005). Stratification by ethnicity indicated significant association between the ATIC 347 GG+GC genotype and non-response to MTX in Caucasians (OR=1.884, 95% CI 1.236-2.873, p=0.003), but not in Asian patients. Similarly, associations were noted for the ATIC 347 C/G polymorphism through analysis using recessive and overdominant models. Meta-analysis revealed association between the ATIC 347 GG+GC genotype and MTX toxicity (OR=1.454 95% CI 1.034-2.044, p=0.032). Stratification by ethnicity indicated significant association between the ATIC 347 GG+GC genotype and MTX toxicity in Caucasians (OR=1.741, 95% CI 1.080-2.806, p=0.023), but not in Asian patients. The ATIC 347 C/G polymorphism may be associated with non-responsiveness to and or toxicity of MTX in Caucasian RA patients.

Fas/FasL, Bcl2 and Caspase-8 gene polymorphisms in Chinese patients with rheumatoid arthritis

Apoptosis signals are necessary for maintaining homeostasis and an adequate immune response. Dysregulation of apoptosis-related genes in the immune system has an important impact on autoimmune diseases such as rheumatoid arthritis (RA). Thus, we investigated the association between Fas rs2234767 G/A, FasL rs763110 C/T, Bcl2 rs12454712 T/C, Bcl2 rs17757541 C/G, and Caspase-8 rs1035142 G/T polymorphisms and RA susceptibility in a Chinese population. These five single-nucleotide polymorphisms (SNPs) were studied in a Chinese population consisting of 615 patients with RA and 839 controls. Genotyping was performed using a custom-by-design 48-Plex SNP scan TM kit. Furthermore, we undertook a meta-analysis between FasL rs763110 C/T and RA. This study indicated that Fas rs2234767 and Bcl2 rs17757541 polymorphisms were risk factors for RA. No association was observed between FasL rs763110 C/T, Bcl2 rs12454712 T/C, and Caspase-8 rs1035142 G/T polymorphisms and RA in this study. The results of this meta-analysis suggested no significant association between FasL rs763110 C/T and RA. However, stratification analysis of this meta-analysis indicated that FasL rs763110 C/T increased the risk of Caucasian RA patients. In conclusion, this study demonstrated that Fas rs2234767 G/A and Bcl2 rs17757541 T/C polymorphisms might be associated with an increased risk of RA. This meta-analysis revealed that FasL rs763110 C/T was associated with an increased risk of Caucasian RA patients.

Dual X-ray Absorptiometry Whole Body Composition of Adipose Tissue in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) may influence not only abdominal fat, but also whole body adiposity, since it is associated with chronic inflammation and disability. The study aims to evaluate the whole body adiposity of RA patients and to assess potential influences of disease specific measures. The study was designed to include Caucasian postmenopausal female RA patients and age-matched postmenopausal female controls. Each subject underwent on the same day clinical examination, laboratory tests, whole body dual X-ray absorptiometry (DXA) composition and physical activity estimation using a self-administered questionnaire. A total of 107 RA women and 104 matched controls were included. Compared to controls, the RA group had less physical activity and a higher prevalence of normal weight obesity. Overfat RA women had a significantly higher toll of inflammation, disease activity, glucocorticoid treatment and sedentary behavior. RA women with inflammation, glucocorticoid treatment and higher disease activity class had higher whole body and trunk adipose tissue indices and higher prevalence of overfat status. Glucocorticoid treatment, inflammation, disease duration and severity correlated with whole body adipose tissue and significantly predicted high adiposity content and overfat phenotypes. RA disease duration and severity are associated with higher whole body and regional adiposity. Low-dose glucocorticoid treatment seems to contribute to adiposity gain and redistribution. Clinicians may need to assess body composition and physical activity in RA patients in order to fully manage cardiovascular outcomes and quality of life.

DISEASE ACTIVITY PREDICTS WHOLE BODY AND REGIONAL LEAN TISSUE IN RHEUMATOID ARTHRITIS – A CROSS-SECTIONAL STUDY

Aim. The study aims to assess the potential influences of rheumatoid arthritis (RA) and its specific disease measures on lean body composition phenotypes of female patients. Methods. The study was cross-sectionally designed to include Caucasian postmenopausal female RA patients and age-matched postmenopausal female controls. All the subjects gave written informed consent and the study was approved by the local ethics committee. Each subject underwent in the same day a clinical examination, laboratory tests, whole body dual X-ray absorptiometry (DXA) composition and physical activity estimation using a self-administered questionnaire. Correlations, differences and predictive power were analyzed with appropriate statistical tests. Results. The study included 107 RA patients and 104 controls. Compared to the normal subjects, who recorded higher levels of physical activity, the RA patients had significantly lower appendicular lean tissue absolute and relative indices and higher prevalence of sarcopenia. The whole body and appendicular lean tissue indices showed significant negative correlations with measures of disease severity (duration, inflammation, quality of life and radiographic progression), independent of age, levels of physical activity, body mass index and smoking. Conclusions. The measures of disease activity and severity independently predict lean tissue phenotypes in RA patients, behaving as risk factors for sarcopenia and rheumatoid cachexia. The diagnosis of RA in itself is a significant predictive factor of sarcopenia.

Putative IL-10 Low Producer Genotypes Are Associated with a Favourable Etanercept Response in Patients with Rheumatoid Arthritis.

Outcome predictors of biologic therapeutic drugs like TNF inhibitors are of interest since side effects like serious infections or malignancy cannot be completely ruled out. Response rates are heterogeneous. The present study addressed the question whether in patients with rheumatoid arthritis (RA) interleukin-10 (IL-10) promoter genotypes with potential relevance for IL-10 production capacity are associated with response to long-term treatment with etanercept. Caucasian RA patients that, according to the EULAR criteria, responded well (n = 25), moderately (n = 17) or not (n = 8) to etanercept therapy (median 36 months, range 4–52), and 160 matched controls were genotyped for the IL-10 promoter SNPs -2849 G>A (rs6703630), -1082 G>A (rs1800896), -819 C>T (rs1800871) and -592 C>A (rs1800872). Haplotypes were reconstructed via mathematic model and tested for associations with disease susceptibility and therapy response. We identified the four predominant haplotypes AGCC, GATA, GGCC, and GACC in almost equal distribution. Patients that responded well carried the putative IL-10 low producer allele -2849 A or the haplotypes AGCC and GATA (RR 2.1 and 4.0, respectively; 95% CI 1.1–4.0 and 1.1–14.8), whereas an unfavourable response was associated with carriage of the putative high producer haplotype GGCC (RR 1.9, 95% CI 1.1–3.3). No significant associations of alleles or haplotypes with disease susceptibility were observed. In RA, a low IL-10 production which is genetically determined rather by haplotypes than by SNPs may favour the response to etanercept treatment. Iatrogenic blockade of TNF may reveal proinflammatory effects of its endogeneous antagonist IL-10. Further studies are needed to correlate these genetic findings to direct cytokine measurements.

Role of key TYMS polymorphisms on methotrexate therapeutic outcome in portuguese rheumatoid arthritis patients.

BackgroundTherapeutic outcome of rheumatoid arthritis (RA) patients treated with methotrexate (MTX) can be modulated by thymidylate synthase (TS) levels, which may be altered by genetic polymorphisms in TS gene (TYMS). This study aims to elucidate the influence of TYMS polymorphisms in MTX therapeutic outcome (regarding both clinical response and toxicity) in Portuguese RA patients.MethodsClinicopathological data from 233 Caucasian RA patients treated with MTX were collected, outcomes were defined and patients were genotyped for the following TYMS polymorphisms: 1) 28 base pairs (bp) variable number tandem repeat (rs34743033); 2) single nucleotide polymorphism C>G (rs2853542); and 3) 6 bp sequence deletion (1494del6, rs34489327). Chi-square and binary logistic regression analyses were performed, using genotype and haplotype-based approaches.ResultsConsidering TYMS genotypes, 3R3R (p = 0.005, OR = 2.34), 3RC3RG (p = 0.016, OR = 3.52) and 6bp− carriers (p = 0.011, OR = 1.96) were associated with non-response to MTX. Multivariate analysis confirmed the increased risk for non-response to MTX in 6bp− carriers (p = 0.016, OR = 2.74). Data demonstrated that TYMS polymorphisms were in linkage disequilibrium (p<0.00001). Haplotype multivariate analysis revealed that haplotypes harboring both 3R and 6bp− alleles were associated with non-response to MTX. Regarding MTX-related toxicity, no statistically significant differences were observed in relation to TYMS genotypes and haplotypes.ConclusionOur study reveals that TYMS polymorphisms could be important to help predicting clinical response to MTX in RA patients. Despite the potential of these findings, translation into clinical practice needs larger studies to confirm these evidences.

The rheumatoid arthritis susceptibility polymorphism PTPN22 C1858T is not associated with leflunomide response or toxicity.

A common polymorphism (C1858T) in the gene that encodes the protein tyrosine phosphatase non-receptor type 22 (PTPN22) is associated with altered T-cell responses and increased susceptibility to rheumatoid arthritis (RA) and other autoimmune diseases. Teriflunomide, the active metabolite of leflunomide, reduces T-cell responses through inhibition of tyrosine kinase p56LCK. We examined a potential association between PTPN22 genotype and response or toxicity to leflunomide in Caucasian RA patients taking leflunomide in combination with other disease-modifying antirheumatic drugs (DMARDs). Patients enrolled in the Royal Adelaide Hospital RA inception cohort and taking leflunomide were eligible for inclusion. Participants were followed for 12months after leflunomide initiation or until either another DMARD was added or leflunomide was ceased. Clinical response according to change in 28-joint Disease Activity Score (DAS28) and cessation due to toxicity were assessed. A total of 94 participants were included in the study, 75 of whom carried the CC genotype, 18 the CT, whereas one individual carried the TT genotype. Over the first 12months of leflunomide treatment, there was no statistically significant relationship between carrying the T allele and change in DAS28 (-0·84 vs. -1·15, P=0·446) nor with cessation of leflunomide treatment due to side effects (P=0·433). These results indicate that PTPN22 C1858T genotype has no effect on response or toxicity outcomes in leflunomide-treated RA patients. This is the first study to evaluate the biologically plausible hypothesis that PTPN22 genotype might be a predictor of response/toxicity to leflunomide therapy. Despite this, PTPN22 genotype was not associated with leflunomide response or toxicity in patients with RA.

THU0457 Tyms Polymorphisms and Methotrexate Therapeutic Outcome in Rheumatoid Arthritis Portuguese Patients: Analysis of Key Polymorphisms

BackgroundTherapeutic outcome of rheumatoid arthritis (RA) patients treated with methotrexate (MTX) could be conditioned by thymidylate synthase (TS) levels, which may be altered by genetic polymorphisms in TS gene (TYMS)...

Association of the AIRE gene with susceptibility to rheumatoid arthritis in a European population: a case control study

IntroductionAIRE is a transcriptional regulator playing a functional role in thymocyte education and negative selection by controlling the expression of peripheral antigens in the thymus. Recently, the AIRE gene was identified as a genetic risk factor for rheumatoid arthritis (RA) in genome wide association (GWA) studies performed in the Japanese population. According to the available data this association is restricted to the Asian population. However, different facts could influence the lack of association in Caucasian populations. The aim of this study was to further investigate the possible role of the AIRE gene in susceptibility to RA in a Caucasian population.MethodsA total of 472 Spanish Caucasian RA patients and 475 ethnically matched controls were included in the study. Three single-nucleotide polymorphisms (SNPs) (rs2776377, rs878081 and rs1055311) with a minor allele frequency >0.05 in the Caucasian population which were not included in the high-throughput platforms used in the GWA studies performed in susceptibility to RA, and two SNPs (rs2075876 and rs1800520) associated with RA in the Japanese population, were selected and genotyped using TaqMan assays.ResultsNo significant differences in the distribution of the alleles of rs2776377, rs2075876, rs1055311 and rs1800520 SNPs between RA patients and controls were observed. Nevertheless, the frequency of the C allele of rs878081 was significantly higher among RA patients (80.5% vs. 74.6% in the control group, pc = 0.012, OR = 1.41, 95%CI 1.13-1.75). Regarding the distribution of the rs878081 genotypes, a higher frequency of CC homozygous individuals was found in the RA patient group (65.56% vs. 56.47% in the control group, pc = 0.013, OR = 1.47, 95%CI 1.12-1.93). The in silico analysis predicted lower affinity to the binding-site of a motif of the transcription NF-κB family and lower transcription levels of AIRE gene for the rs878081C risk variantConclusionsOur findings suggest that the AIRE gene is associated with susceptibility to RA in the Spanish population. Probably, this association has not been detected in the European population in the GWA studies because the earliest high-throughput platforms did not include SNP suitable markers (e.g. rs878081).

Polymorphisms in genes controlling inflammation and tissue repair in rheumatoid arthritis: a case control study

BackgroundVarious cytokines and inflammatory mediators are known to be involved in the pathogenesis of rheumatoid arthritis (RA). We hypothesized that polymorphisms in selected inflammatory response and tissue repair genes contribute to the susceptibility to and severity of RA.MethodsPolymorphisms in TNFA, IL1B, IL4, IL6, IL8, IL10, PAI1, NOS2a, C1INH, PARP, TLR2 and TLR4 were genotyped in 376 Caucasian RA patients and 463 healthy Caucasian controls using single base extension. Genotype distributions in patients were compared with those in controls. In addition, the association of polymorphisms with the need for anti-TNF-α treatment as a marker of RA severity was assessed.ResultsThe IL8 781 CC genotype was associated with early onset of disease. The TNFA -238 G/A polymorphism was differentially distributed between RA patients and controls, but only when not corrected for age and gender. None of the polymorphisms was associated with disease severity.ConclusionsWe here report an association between IL8 781 C/T polymorphism and age of onset of RA. Our findings indicate that there might be a role for variations in genes involved in the immune response and in tissue repair in RA pathogenesis. Nevertheless, additional larger genomic and functional studies are required to further define their role in RA.

Association of higher rheumatoid arthritis disease activity during pregnancy with lower birth weight: Results of a national prospective study

To determine the outcome of pregnancy in women with rheumatoid arthritis (RA) in relation to disease activity and medication use during the pregnancy. In a prospective study, pregnant women with RA were evaluated before conception (when possible), during each trimester of the pregnancy, and postpartum. Clinical characteristics, disease activity, medication use, and pregnancy outcome were analyzed. To examine the independent influence of prednisone use and disease activity on birth weight, regression analyses were performed, with adjustments for gestational age of the child at delivery, the sex of the newborn, and the mother's smoking status, education level, parity, and use of an assisted reproduction technique. Kaplan-Meier curve analyses were performed to examine the association between medication use and gestational age at delivery. Data from 152 Caucasian RA patients with singleton pregnancies were available. Both the mean +/- SD birth weight (3,379 +/- 564 gm) and the mean +/- SD birth weight standard deviation score (SDS; +0.1 +/- 1.1), which is the birth weight adjusted for the gestational age and sex of the newborn, were comparable with those in the general population. On multiple linear regression analyses of birth weight and birth weight SDS, both of which were adjusted for covariates, only disease activity was associated with lower birth weight (P = 0.025). The gestational age at delivery was significantly lower in women who were taking prednisone (38.8 versus 39.9 weeks; P = 0.001), and their delivery was more often premature (<37 weeks; P = 0.004). Pregnancy outcome in women with well-controlled RA is comparable with that in the general population. The effect of prednisone on birth weight is mediated by a lower gestational age at delivery, whereas a higher level of disease activity independently influences birth weight negatively, suggesting an immune-mediated mechanism.

CTLA4/ICOS gene variants and haplotypes are associated with rheumatoid arthritis and primary biliary cirrhosis in the Canadian population

The co-occurrence of different autoimmune diseases in patients and their families suggests the presence of shared genetic risk factors. Two compelling candidate autoimmune disease susceptibility genes are those that encode CTLA4 and inducible costimulator (ICOS), immunoregulatory proteins. Associations of CTLA4 polymorphisms with various autoimmune diseases have been reported, but for rheumatoid arthritis (RA) and primary biliary cirrhosis (PBC), the association data are inconsistent and have largely excluded analysis of polymorphisms in the ICOS gene adjacent to CTLA4. We undertook this study to examine whether CTLA4 and ICOS influence RA and PBC susceptibility by testing CTLA4/ICOS polymorphisms for association with these diseases in Canadian subjects. Caucasian RA patients (n = 1,140), PBC patients (n = 481), and controls (n = 1,248) were typed for 21 biallelic polymorphisms across the CTLA4/ ICOS genes using a multiplex genotyping array, and the results were analyzed using a false discovery rate method to correct for multiple testing. Significant associations of multiple CTLA4 and ICOS gene polymorphisms with RA and PBC were observed, with the strongest association signals for both diseases coming from a CTLA4/ICOS intergenic single-nucleotide polymorphism, rs17268364 (corrected P [P(corr)] = 6.0 x 10(-4) and P(corr) < 1.0 x 10(-4), respectively). Significant associations, which were common to both diseases, were also observed with other alleles and haplotypes across 3 linkage disequilibrium blocks within the CTLA4 gene, the intergenic region, and the ICOS gene. Our results provide evidence for RA and PBC association with the CTLA4/ICOS locus and suggest that the risk allele(s) within this region may be common to both diseases.

Association analysis of the interleukin 17A gene in Caucasian rheumatoid arthritis patients from Norway and New Zealand

Elevated levels of IL-17A have been detected in the inflamed synovium of RA patients, and murine arthritis models deficient in IL17A have shown reduced inflammation. Our aim was to investigate IL17A as a candidate gene for RA, and to assess correlations between risk variants and disease phenotypes. Five single nucleotide polymorphisms (SNPs) were selected to tag the genetic variability of the IL17A region and were genotyped by TaqMan technology on 950 RA cases and 933 random controls from Norway. Associations to progression of radiographic damage and presence of autoantibodies were examined in a 10-yr follow-up cohort of early RA. In addition, 580 RA patients and 504 controls from New Zealand were used as a replication data set. A weak association between RA and the promoter SNP rs2275913 [odds ratio (OR) = 1.17; 95% CI 1.02, 1.34; P = 0.02] was found in the Norwegian population. The association was also evident at the genotype level where it indicated a recessive model. The allelic association was not replicated in the RA cohort from New Zealand (OR = 0.96; 95% CI 0.81, 1.16; P = 0.69). However, combined analysis suggested a weak recessive association (OR = 1.19; 95% CI 1.02, 1.37; P = 0.02). No significant associations were observed with radiographic progression, anti-cyclic citrullinated peptide or IgM-RF. Modest evidence of an association with IL17A in Norwegian RA patients was observed. Although, our findings were not replicated in an independent RA material from New Zealand, a significant common risk estimate indicated that IL17A warrants further investigation in RA.

The ITGAV rs3738919 variant and susceptibility to rheumatoid arthritis in four Caucasian sample sets.

IntroductionAngiogenesis is an important process in the development of destructive synovial pannus in rheumatoid arthritis (RA). The ITGAV +gene encodes a cell cycle-associated antigen, integrin ανβ 3, which plays a role in RA angiogenesis. Previously, two independent studies identified an association between the major allele of the ITGAV single-nucleotide polymorphism (SNP) rs3738919 and RA. We therefore tested this association in an independent study using New Zealand (NZ) and Oxford (UK) RA case control samples.MethodsWe compared genotype frequencies in 740 NZ Caucasian RA patients and 553 controls genotyped for rs3738919, using a polymerase chain reaction-restriction fragment length polymorphism assay. A TaqMan genotyping SNP assay was used to type 713 Caucasian RA patients and 515 control samples from Oxford for the rs3738919 variant. Association of rs3738919 with RA was tested in these two sample sets using the chi-square goodness-of-fit test. The Mantel-Haenszel test was used to perform a meta-analysis, combining the genetic results from four independent Caucasian case control cohorts, consisting of 3,527 cases and 4,126 controls. Haplotype analysis was also performed using SNPs rs3911238, rs10174098 and rs3738919 in the Wellcome Trust Case Control Consortium, NZ and Oxford case control samples.ResultsWe found no evidence for association between ITGAV and RA in either the NZ or Oxford sample set (odds ratio [OR] = 0.88, Pallelic = 0.11 and OR = 1.18, Pallelic = 0.07, respectively). Inclusion of these data in a meta-analysis (random effects) of four independent cohorts (3,527 cases and 4,126 controls) weakens support for the hypothesis that rs3738919 plays a role in the development of RA (ORcombined = 0.92, 95% confidence interval 0.80 to 1.07; P = 0.29). No consistent haplotype associations were evident.ConclusionsAssociation of ITGAV SNP rs7378919 with RA was not replicated in NZ or Oxford case control sample sets. Meta-analysis of these and previously published data lends limited support for a role for the ITGAV in RA in Caucasians of European ancestry.

Lack of an Association of GNB3 C825T Polymorphism and Blood Pressure in Patients with Rheumatoid Arthritis

G-protein beta 3 subunit (GNB3) C825T (rs5443) single nucleotide polymorphism (SNP) has been implicated as a risk factor for essential hypertension in the general population. The effects of this SNP may be more prominent in subjects with endothelial dysfunction (ED). Rheumatoid arthritis (RA) is associated with ED and has a high prevalence of hypertension. Thus far, this SNP has not been studied in RA patients. We genotyped 383 RA patients and 432 controls. GNB3 C825T was identified using real-time polymerase chain reaction (PCR) and melting curve analysis. There were no differences in the frequencies of the GNB3 C825T genotype and alleles between RA and controls. Within RA patients, prevalence of hypertension did not differ across genotypes. The TT versus CC+CT contrast yielded an adjusted odds ratio (OR) of 0.92 (95% CI: 0.49 to 1.76, p = 0.813), the contrast of TT+CT versus CC an adjusted OR of 2.17 (95% CI: 0.885 to 5.30, p = 0.091), whereas that of the T allele versus C allele an adjusted OR of 1.11 (95% CI: 0.76 to 1.61, p = 0.604). Systolic and diastolic blood pressure levels were not significantly different across the three genotypic groups. No significant interaction was observed between GNB3 825C/T polymorphism and serum endothelin levels. Data from the present study suggest that the T825 variant of the G protein β3 subunit gene is unlikely to constitute major susceptibility loci for essential hypertension in Caucasian RA patients. Further larger studies are required to confirm our findings and assess the interaction of rs5443 with environmental factors.

Association of the tumour necrosis factor-308 variant with differential response to anti-TNF agents in the treatment of rheumatoid arthritis

Anti-tumour necrosis factor (TNF) agents have revolutionized the treatment of patients with rheumatoid arthritis (RA). These therapies are, however, expensive and 30% of patients fail to respond. In a large cohort of Caucasian RA patients treated with anti-TNF medications (total n = 1050, etanercept n = 455, infliximab n = 450), we investigated whether genotypes of eight single nucleotide polymorphisms in the region containing the TNF gene were associated with response to anti-TNF therapy. Linear regression analyses adjusted for baseline 28 joint disease activity score (DAS28), baseline health assessment questionnaire score, gender and concurrent disease modifying anti-rheumatic drug treatment were used to assess association of these polymorphisms with treatment response, defined by change in DAS28 after 6 months. Analyses were performed in the entire cohort, and also stratified by anti-TNF agent. Association between DAS28 response and TNF-308 (rs1800629) genotype (P = 0.001) was detected across the whole cohort. After stratification by anti-TNF agent, the rare TNF-308AA genotype was associated with a significantly poorer response compared with TNF-308GG in etanercept (P = 0.001, n = 7) but not infliximab (P = 0.8, n = 17) treated patients. Conversely, the GA genotype at TNF-238 (rs361525) was associated with a poorer response to infliximab (P = 0.028, n = 40), but not etanercept (P = 0.6, n = 33). Owing to the small numbers of patients in some of the genotype groups examined, our data must be regarded as preliminary and will require replication in further large cohorts of anti-TNF-treated patients. If confirmed, our findings suggest the potential for genotype at these markers to aid selection of anti-TNF agent in patients with RA.

The shared epitope hypothesis in rheumatoid arthritis: Evaluation of alternative classification criteria in a large UK Caucasian cohort

Many classification systems for the HLA-DRB1 allelic association with rheumatoid arthritis (RA) have been reported, but few have been validated in additional populations. We sought to evaluate 3 different DRB1 allele classification systems in a large cohort of Caucasian RA patients and control subjects in the UK. HLA-DRB1 typing was undertaken in 1,325 Caucasian RA patients and 462 healthy Caucasian controls who were residents of the UK. Logistic regression analyses were performed to investigate the different classification systems. We confirmed the association between the susceptibility alleles S2 and S3P, as proposed by Tezenas du Montcel, and the presence of RA in UK Caucasians. A significant hierarchy of risk was observed within the S3P allele group. There was no evidence of a significant association between DRB1*1001 and RA. Our data did not support the hypothesis that an isoleucine at position 67 conferred protection against RA, other than in contrast to the susceptibility alleles. However, the presence of an aspartic acid at amino acid 70 did appear to confer some degree of protection. We were unable to fully substantiate any of the 3 recent revisions of the shared epitope hypothesis in this large cohort of Caucasian RA patients and control subjects in the UK. This reinforces the importance of evaluating disease susceptibility alleles in different Caucasian populations as well as in other ethnic groups. In particular, it will be important to clarify the precise DRB1 association in a given population before DRB1 genotyping is incorporated into clinical diagnostic or treatment algorithms.