[Show abstract][Hide abstract] ABSTRACT: Le gène CLEC12A code pour un immunorécepteur inhibiteur, situé sur le locus 12p13.2. L’augmentation d’ARNm CLEC12A étant corrélée à des valeurs de facteur rhumatoïde supérieures à 40 IU/mL dans les fibroblastes synoviaux rhumatoïdes, cette étude évalue l’association potentielle entre CLEC12A et la PR au moyen d’une approche phénotypique.MéthodesHuit TagSNPs (marqueurs de polymorphismes nucléotidiques simples) ont été génotypés sur une cohorte de « découverte » originaire d’Europe de l’Ouest. Les analyses statistiques reposent sur le test de déséquilibre de transmission et sur les calculs du risque relatif et des intervalles de confiance à 95 %. Les fréquences haplotypiques observées ont été comparées aux fréquences attendues en utilisant un test d’association basé sur les familles (FBAT). Les associations statistiquement significatives ont été ensuite testées dans une seconde cohorte de patients d’Europe de l’Ouest atteints de PR et sans lien de parenté.RésultatsUn déséquilibre de transmission de l’allèle C du marqueur SNP de rs1323461 a été observé (transmission de 56,6 % de l’allèle C, p = 0,046) dans la cohorte « découverte ». Le risque relatif des génotypes AC et CC était élevé en comparaison avec le génotype AA (risque relatif = 4,08 ; IC 95 % : 1,52–10,95, p non corrigée = 2,1 × 10−3), particulièrement dans le sous-groupe atteint de PR érosive (risque relatif = 5,27 ; IC 95 % : 1,53–18,19, p non corrigée = 2,1 × 10−3), les probabilités demeurant statistiquement significatives après correction conservative de Bonferroni. L’haplotype CGAGCCGA a été observé plus fréquemment qu’attendu (p = 0,013). Dans la seconde cohorte, l’allèle C avait tendance à être plus fréquent chez les patients polyarthritiques (82,4 %) que chez les témoins (79,2 %) (p = 0,069).Conclusion
Nous rapportons une association génétique potentielle de CLEC12A avec la PR. Étant donné que CLEC12A code pour la lectine MICL « myeloid inhibitory C-type lectin-like », un récepteur qui module la synthèse des cytokines, ce dernier pourrait contribuer à la pathogenèse de la PR.
Revue du Rhumatisme 12/2012; 79(6):523-529. DOI:10.1016/j.rhum.2012.02.009
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: The CLEC12A gene codes for an immune inhibitory receptor that maps to 12p13.2. Since an increase in CLEC12A mRNA correlates with rheumatoid factor values greater than 40IU/ml in rheumatoid fibroblast-like synovial cells, this study assessed the potential of an association between CLEC12A and rheumatoid arthritis (RA) using a phenotype-based approach. METHODS: A discovery cohort of Western European ethnicity was genotyped for eight tag single nucleotide polymorphisms. Statistical analyses relied on the transmission disequilibrium test, relative risk and 95% confidence interval (CI) calculations. Observed haplotype frequencies were compared to expected frequencies using a family-based association test. Statistically significant associations were further tested in a second cohort of unrelated West-European RA patients. RESULTS: An overtransmission of the C allele of the rs1323461 tag single nucleotide polymorphism was observed (56.6% of allele C transmission, P=0.046) in the discovery cohort. The relative risk of the AC and CC genotypes when compared to the AA genotype was high (relative risk=4.08; 95% CI: 1.52-10.95, uncorrected P=2.1×10(-3)), particularly in the subgroup of erosive RA (relative risk=5.27; 95% CI: 1.53-18.19, uncorrected P=2.1×10(-3)), both remaining statistically significant after conservative Bonferroni's correction. The CGAGCCGA haplotype was observed more frequently than expected (P=0.013). In the second cohort, the C allele had a tendency to be more frequent in RA patients (82.4%) than controls (79.2%) (P=0.069). CONCLUSION: We report a potential genetic association of CLEC12A with RA. Since CLEC12A encodes for the myeloid inhibitory C-type lectin-like receptor that modulates cytokine synthesis, this receptor may contribute to the pathogenesis of RA.
[Show abstract][Hide abstract] ABSTRACT: Increased expression of type I IFN genes, also referred to as an IFN signature, has been detected in various autoimmune diseases including rheumatoid arthritis (RA). Interferon regulatory factors, such as IRF5, coordinate type I IFN expression. Multiple IRF5 variants were suggested as autoimmunity susceptibility factors.
As the linkage proof remains important to establish fully any genetic RA susceptibility factor, the authors took advantage of the largest reported European trio family resource dedicated to RA to test for linkage IRF5 and performed a genotype-phenotype analysis.
1140 European Caucasian individuals from 380 RA trio families were genotyped for IRF5 rs3757385, rs2004640 and rs10954213 single nucleotide polymorphisms (SNP).
Single marker analysis provided linkage evidence for each IRF5 SNP investigated. IRF5 linked to RA with two haplotypes: the CTA risk haplotype 'R' (transmission (T)=60.6%, p=23.1×10(-5)) and the AGG protective haplotype 'P' (T=39.6%, p=0.0015). Linkage was significantly stronger in non-erosive disease for both IRF5 R and P haplotypes (T=73.9%, p=4.20×10(-5) and T=19.6%, p=3.66×10(-5), respectively). Multivariate logistic regression analysis found IRF5 linked to RA independently of the rheumatoid factor status. IRF5 RR and PP haplotypic genotypes were associated with RA, restricted to the non-erosive phenotype: p=1.68×10(-4), OR 4.80, 95% CI 2.06 to 11.19; p=0.003, OR 0.17, 95% CI 0.05 to 0.57, respectively.
This study provides the 'association and linkage proof' establishing IRF5 as a RA susceptibility gene and the identification of a genetic factor that seems to contribute to the modulation of the erosive phenotype. Further studies are warranted to clarify the role of IRF5 in RA and its subphenotypes.
Annals of the rheumatic diseases 10/2010; 70(1):117-21. DOI:10.1136/ard.2010.129171 · 10.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rheumatoid arthritis (RA) is an inflammatory joint disease with features of an autoimmune disease with female predominance. Candidate genes located on the X-chromosome were selected for a family trio-based association study.
A total of 1452 individuals belonging to 3 different sample sets were genotyped for 16 single-nucleotide polymorphisms (SNP) in 7 genes. The first 2 sets consisted of 100 family trios, each of French Caucasian origin, and the third of 284 additional family trios of European Caucasian origin. Subgroups were analyzed according to sex of patient and presence of anti-cyclic citrullinated peptide (anti-CCP) autoantibodies.
Four SNP were associated with RA in the first sample set and were genotyped in the second set. In combined analysis of sets 1 and 2, evidence remained for association of 3 SNP in the genes UBA1, TIMP1, and IL9R. These were again genotyped in the third sample set. Two SNP were associated with RA in the joint analysis of all samples: rs6520278 (TIMP1) was associated with RA in general (p = 0.035) and rs3093457 (IL9R) with anti-CCP-positive RA patients (p = 0.037) and male RA patients (p = 0.010). A comparison of the results with data from whole-genome association studies further supports an association of RA with TIMPL The sex-specific association of rs3093457 (IL9R) was supported by the observation that men homozygous for rs3093457-CC are at a significantly higher risk to develop RA than women (risk ratio male/female = 2.98; p = 0.048).
We provide evidence for an association of at least 2 X-chromosomal genes with RA: TIMP1 (rs6520278) and IL9R (rs3093457).
The Journal of Rheumatology 10/2009; 36(10):2149-57. DOI:10.3899/jrheum.090059 · 3.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A candidate gene approach, in a large case-control association study in the Dutch population, has shown that a 480 kb block on chromosome 4q27 encompassing KIAA1109/Tenr/IL2/IL21 genes is associated with rheumatoid arthritis. Compared with case-control association studies, family-based studies have the added advantage of controlling potential differences in population structure. Therefore, our aim was to test this association in populations of European origin by using a family-based approach.
A total of 1,302 West European white individuals from 434 trio families were genotyped for the rs4505848, rs11732095, rs6822844, rs4492018 and rs1398553 polymorphisms using the TaqMan Allelic discrimination assay (Applied Biosystems). The genetic association analyses for each SNP and haplotype were performed using the Transmission Disequilibrium Test and the genotype relative risk.
We observed evidence for association of the heterozygous rs4505848-AG genotype with rheumatoid arthritis (P = 0.04); however, no significance was found after Bonferroni correction. In concordance with previous findings in the Dutch population, we observed a trend of undertransmission for the rs6822844-T allele and rs6822844-GT genotype to rheumatoid arthritis patients. We further investigated the five SNP haplotypes of the KIAA1109/Tenr/IL2/IL21 gene region. We observed, as described in the Dutch population, a nonsignificant undertransmission of the AATGG haplotype to rheumatoid arthritis patients.
Using a family-based study, we have provided a trend for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in populations of European descent. Nevertheless, we failed to replicate a significant association of this region in our rheumatoid arthritis family sample. Further investigation of this region, including detection and testing of all variants, is required to confirm rheumatoid arthritis association.
[Show abstract][Hide abstract] ABSTRACT: We recently showed, using a candidate gene approach in a case-control association study, that a 65-kb block encompassing tumor necrosis factor receptor-associated factor 1 (TRAF1) and C5 is strongly associated with rheumatoid arthritis (RA). Compared with case-control association studies, family-based studies have the added advantage of controlling potential differences in population structure and are not likely to be hampered by variation in population allele frequencies, as is seen for many genetic polymorphisms, including the TRAF1/C5 locus. The aim of this study was to confirm this association in populations of European origin by using a family-based approach.
A total of 1,356 western European white individuals from 452 "trio" families were genotyped for the rs10818488 polymorphism, using the TaqMan allelic discrimination assay.
We observed evidence for association, demonstrating departure from Mendel's law, with an overtransmission of the rs10818488 A allele (A = 55%; P = 0.036). By taking into consideration parental phenotypes, we also observed an increased A allele frequency in affected versus unaffected parents (A = 64%; combined P = 0.015). Individuals carrying the A allele had a 1.2-fold increased risk of developing RA (allelic odds ratio 1.24, 95% confidence interval 1.04-1.50).
Using a family-based study that is robust against population stratification, we provide evidence for the association of the TRAF1/C5 rs10818488 A allele and RA in populations of European descent, further substantiating our previous findings. Future functional studies should yield insight into the biologic relevance of this locus to the pathways involved in RA.
[Show abstract][Hide abstract] ABSTRACT: The integrin αvβ3, whose αv subunit is encoded by the ITGAV gene, plays a key role in angiogenesis. Hyperangiogenesis is involved in rheumatoid arthritis (RA) and the ITGAV gene is located in 2q31, one of the suggested RA susceptibility loci. Our aim was to test the ITGAV gene for association and linkage to RA in a family-based study from the European Caucasian population.
Two single nucleotide polymorphisms were genotyped by PCR-restriction fragment length polymorphism in 100 French Caucasian RA trio families (one RA patient and both parents), 100 other French families and 265 European families available for replication. The genetic analyses for association and linkage were performed using the comparison of allelic frequencies (affected family-based controls), the transmission disequilibrium test, and the genotype relative risk.
We observed a significant RA association for the C allele of rs3738919 in the first sample (affected family-based controls, RA index cases 66.5% versus controls 56.7%; P = 0.04). The second sample showed the same trend, and the third sample again showed a significant RA association. When all sets were combined, the association was confirmed (affected family-based controls, RA index cases 64.6% versus controls 58.1%; P = 0.005). The rs3738919-C allele was also linked to RA (transmission disequilibrium test, 56.5% versus50% of transmission; P = 0.009) and the C-allele-containing genotype was more frequent in RA index cases than in controls (RA index cases 372 versus controls 339; P = 0.002, odds ratio = 1.94, 95% confidence interval = 1.3–2.9).
The rs3738919-C allele of the ITGAV gene is associated with RA in the European Caucasian population, suggesting ITGAV as a new minor RA susceptibility gene.
[Show abstract][Hide abstract] ABSTRACT: The tyrosine phosphatase PTPN22 allele 1858T has been associated with rheumatoid arthritis (RA) and other autoimmune diseases. RA is the most frequent of those multifactorial diseases. The RA association was usually restricted to serum rheumatoid factor positive disease (RF+). No interaction was shown with HLA-DRB1, the first RA gene. Many case-control studies replicated the RA association, showing an allele frequency increase of approximately 5% on average and large variations of population allele frequencies (2.1-15.5%). In multifactorial diseases, the final proof for a new susceptibility allele is provided by departure from Mendel's law (50% transmission from heterozygous parents). For PTPN22-1858T allele, convincing linkage proof was available only for type 1 diabetes. We aimed at providing this proof for RA. We analyzed 1,395 West European Caucasian individuals from 465 "trio" families. We replicated evidence for linkage, demonstrating departure from Mendel's law in this subset of early RA onset patients. We estimated the overtransmission of the 1858T allele in RF+ families: T = 63%, P < 0.0007. The 1858T allele frequency increased from 11.0% in controls to 17.4% in RF+ RA for the French Caucasian population and the susceptibility genotype (1858T/T or T/C) from 20.2% to 31.6% [odds ratio (OR) = 1.8 (1.2-2.8)]. In conclusion, we provided the linkage proof for the PTPN22-1858T allele and RF+ RA. With diabetes and RA, PTPN22 is therefore a "linkage-proven" autoimmunity gene. PTPN22 accounting for approximately 1% of the RA familial aggregation, many new genes could be expected that are as many leads to definitive therapy for autoimmune diseases.
Proceedings of the National Academy of Sciences 02/2007; 104(5):1649-54. DOI:10.1073/pnas.0610250104 · 9.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Group for the Respect of Ethics and Excellence in Science (GREES) organized a working group to assess the value of time to joint surgery as a potential therapeutic failure outcome criterion for osteoarthritis (OA) of the hip or knee in the assessment of potential structure modifying agents.
PubMed was searched for manuscripts from 1976 to 2004. Relevant studies were discussed at a 1-day meeting.
There are no accepted guidelines for 'time to' and 'indications for' joint replacement surgery. A limited number of trials have examined joint replacement surgery within the study population. Several parameters, particularly joint space narrowing (interbone distance), correlate with surgical intervention. However, at the level of the knee, none of the parameters have positive predictive value for joint replacement surgery better than 30%. In contrast, lack of significant joint space narrowing has a strong negative predictive value for joint replacement surgery (>90%), that remains after controlling for OA pain severity.
At this time, GREES cannot recommend time to joint surgery as a primary endpoint of failure for structure modifying trials of hip or knee OA-as the parameter has sensitivity but lacks specificity. In contrast, in existing trials, a lack of progression of joint space narrowing has predictive value of >90% for not having surgery. GREES suggests utilizing joint space narrowing (e.g., >0.3-0.7 mm) combined with a lack of clinically relevant improvement in symptoms (e.g., >/=20-25%) for 'failure' of a secondary outcome in structure modifying trials of the hip and knee.
Osteoarthritis and Cartilage 01/2005; 13(1):13-9. DOI:10.1016/j.joca.2004.10.012 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To analyse the durability of the responses after haematopoietic stem cell transplantation (HSCT) for severe systemic sclerosis (SSc) and determine whether the high transplant related mortality (TRM) improved with experience. This EBMT/EULAR report describes the longer outcome of patients originally described in addition to newly recruited cases.
Only patients with SSc, treated by HSCT in European phase I-II studies from 1996 up to 2002, with more than 6 months of follow up were included. Transplant regimens were according to the international consensus statements. Repeated evaluations analysed complete, partial, or non-response and the probability of disease progression and survival after HSCT (Kaplan-Meier).
Given as median (range). Among 57 patients aged 40 (9.1-68.7) years the skin scores improved at 6 (n = 37 patients), 12 (n = 30), 24 (n = 19), and 36 (n = 10) months after HSCT (p<0.005). After 22.9 (4.5-81.1) months, partial (n = 32) or complete response (n = 14) was seen in 92% and non-response in 8% (n = 4) of 50 observed cases. 35% of the patients with initial partial (n = 13/32) or complete response (n = 3/14) relapsed within 10 (2.2-48.7) months after HSCT. The TRM was 8.7% (n = 5/57). Deaths related to progression accounted for 14% (n = 8/57) of the 23% (n = 13/57) total mortality rate. At 5 years, progression probability was 48% (95% CI 28 to 68) and the projected survival was 72% (95% CI 59 to 75).
This EBMT/EULAR report showed that response in two thirds of the patients after HSCT was durable with an acceptable TRM. Based on these results prospective, randomised trials are proceeding.
Annals of the Rheumatic Diseases 08/2004; 63(8):974-81. DOI:10.1136/ard.2003.011205 · 10.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine cost-effectiveness of folic or folinic acid supplementation in patients with rheumatoid arthritis (RA) who started methotrexate (MTX) treatment.
An economic evaluation, performed alongside a randomized, double blind, placebo controlled trial with followup of 48 weeks. Patients started MTX with placebo (n = 137), folic acid (n = 133), or folinic acid (n = 141). Outcome measures were drug survival and quality-adjusted life-years (QALY), measured with the EuroQol questionnaire. Both medical and nonmedical costs were analyzed.
Drug survival after 48 weeks was 60% for placebo, 81% for folic acid, and 87% for folinic acid. QALY during a 48 week period were 0.55 (95% CI 0.52-0.58) in the placebo group, 0.55 (95% CI 0.52-0.58) in the folic acid group, and 0.58 (95% CI 0.56-0.60) in the folinic acid group. Mean medical costs were 1398 US dollars (placebo), 1409 US dollars (folic acid), and 1776 US dollars (folinic acid). Mean total costs were 3339 US dollars, 3632 US dollars, and 3296 US dollars, respectively.
In terms of resource deployment, no statistically significant difference was found between the 3 strategies. The preferred strategy consists of folic acid supplementation because of improved drug survival.
The Journal of Rheumatology 06/2004; 31(5):902-8. · 3.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The presence of anti-alpha-fodrin autoantibodies has been reported to be a highly specific and sensitive test for the diagnosis of Sjögren's syndrome (SjS). We looked (in Nijmegen) for anti-alpha-fodrin, anti-Ro60, and anti-La autoantibodies in a cohort of 51 patients with rheumatic diseases (primary SjS , secondary SjS 6, rheumatoid arthritis [RA] 12, systemic lupus erythematosus [SLE] 6, and scleroderma 6) and in 28 healthy subjects, using ELISA, immunoblotting, and immunoprecipitation. The same samples were analyzed with an alternative anti-alpha-fodrin ELISA in Hanover. The Nijmegen ELISA of the sera from primary SjS showed sensitivities of 43% and 48% for IgA- and IgG-type anti-alpha-fodrin antibodies, respectively. The Hanover ELISA showed sensitivities of 38% and 10% for IgA- and IgG-type anti-alpha-fodrin antibodies, respectively. The ELISAs for alpha-fodrin showed six (Nijmegen) and four (Hanover) anti-alpha-fodrin-positive RA sera. IgA and IgG anti-fodrin antibodies were also present in four patients with secondary SjS. The sensitivities of Ro60 and La-antibodies in the Nijmegen ELISA were 67% and 62%, respectively. Unlike anti-alpha-fodrin antibodies, all anti-Ro60 and anti-La positive sera could be confirmed by immunoblotting or RNA immunoprecipitation. Thus, anti-Ro and anti-La autoantibodies were more sensitive than anti-alpha-fodrin autoantibodies in ELISA and were more frequently confirmed by other techniques. Anti-La antibodies appear to be more disease-specific than anti-alpha-fodrin antibodies, which are also found in RA sera. Therefore, the measurement of anti-alpha-fodrin autoantibodies does not add much to the diagnosis of Sjögren's syndrome.