Association between IL-18 gene polymorphisms and biopsy-proven giant cell arteritis

7 pages, 1 figure, 1 table.-- Research article.[Introduction] The objective was to investigate the potential implication of the IL18 gene promoter polymorphisms in the susceptibility to giant-cell arteritis (GCA).[Methods] In total, 212 patients diagnosed with biopsy-proven GCA were included in this study. DNA from patients and matched controls was obtained from peripheral blood. Samples were genotyped for the IL18-137 G>C (rs187238), the IL18-607 C>A (rs1946518), and the IL18-1297 T>C (rs360719) gene polymorphisms with polymerase chain reaction, by using a predesigned TaqMan allele discrimination assay.[Results] No significant association between the IL18-137 G>C polymorphism and GCA was found. However, the IL18 -607 allele A was significantly increased in GCA patients compared with controls (47.8% versus 40.9% in patients and controls respectively; P = 0.02; OR, 1.32; 95% CI, 1.04 to 1.69). It was due to an increased frequency of homozygosity for the IL18 -607 A/A genotype in patients with GCA (20.4%) compared with controls (13.4%) (IL18 -607 A/A versus IL18 -607 A/C plus IL18 -607 C/C genotypes: P = 0.04; OR, 1.59; 95% CI, 1.02 to 2.46). Also, the IL18-1297 allele C was significantly increased in GCA patients (30.7%) compared with controls (23.0%) (P = 0.003; OR, 1.48; 95% CI, 1.13 to 1.95). In this regard, an increased susceptibility to GCA was observed in individuals carrying the IL18-1297 C/C or the IL18-1297 C/T genotypes compared with those carrying the IL18-1297 T/T genotype (IL18-1297 C/C plus IL18-1297 T/C versus IL18-1297 T/T genotype in GCA patients compared with controls: P = 0.005; OR, 1.61; 95% CI, 1.15 to 2.25). We also found an additive effect of the IL18 -1297 and -607 polymorphisms with TLR4 Asp299Gly polymorphism. The OR for GCA was 1.95 for combinations of genotypes with one or two risk alleles, whereas carriers of three or more risk alleles have an OR of 3.7.[Conclusions] Our results show for the first time an implication of IL18 gene-promoter polymorphisms in the susceptibility to biopsy-proven GCA. In addition, an additive effect between the associated IL18 and TLR4 genetic variants was observed.This study was supported by a grant from Fondo de Investigaciones Sanitarias PI06-0024 (Spain) and in part by Junta de Andalucía, grupo CTS-180 (Spain). This work was partially supported by the RETICS Program, RD08/0075 (RIER), from Instituto de Salud Carlos III (ISCIII).Peer reviewe

Tocilizumab in visual involvement of giant cell arteritis: a multicenter study of 471 patients

Background: Visual involvement is the most feared complication of giant cell arteritis (GCA). Information on the efficacy of tocilizumab (TCZ) for this complication is scarce and controversial. Objective: We assessed a wide series of GCA treated with TCZ, to evaluate its role in the prevention of new visual complications and its efficacy when this manifestation was already present before the initiation of TCZ. Design: This is an observational multicenter study of patients with GCA treated with TCZ. Methods: Patients were divided into two subgroups according to the presence or absence of visual involvement before TCZ onset. Visual manifestations were classified into the following categories: transient visual loss (TVL), permanent visual loss (PVL), diplopia, and blurred vision. Results: Four hundred seventy-one GCA patients (mean age, 74 +/- 9 years) were treated with TCZ. Visual manifestations were observed in 122 cases (26%), of which 81 were present at TCZ onset: PVL (n = 60; unilateral/bilateral: 48/12), TVL (n = 17; unilateral/bilateral: 11/6), diplopia (n = 2), and blurred vision (n = 2). None of the patients without previous visual involvement or with TVL had new episodes after initiation of TCZ, while only 11 out of 60 (18%) patients with PVL experienced some improvement. The two patients with diplopia and one of the two patients with blurred vision improved. Conclusion: TCZ may have a protective effect against the development of visual complications or new episodes of TVL in GCA. However, once PVL was established, only a few patients improved

A genome-wide association study follow-up suggests a possible role for PPARG in systemic sclerosis susceptibility

Introduction: A recent genome-wide association study (GWAS) comprising a French cohort of systemic sclerosis (SSc) reported several non-HLA single-nucleotide polymorphisms (SNPs) showing a nominal association in the discovery phase. We aimed to identify previously overlooked susceptibility variants by using a follow-up strategy.<p></p> Methods: Sixty-six non-HLA SNPs showing a P value <10-4 in the discovery phase of the French SSc GWAS were analyzed in the first step of this study, performing a meta-analysis that combined data from the two published SSc GWASs. A total of 2,921 SSc patients and 6,963 healthy controls were included in this first phase. Two SNPs, PPARG rs310746 and CHRNA9 rs6832151, were selected for genotyping in the replication cohort (1,068 SSc patients and 6,762 healthy controls) based on the results of the first step. Genotyping was performed by using TaqMan SNP genotyping assays. Results: We observed nominal associations for both PPARG rs310746 (PMH = 1.90 × 10-6, OR, 1.28) and CHRNA9 rs6832151 (PMH = 4.30 × 10-6, OR, 1.17) genetic variants with SSc in the first step of our study. In the replication phase, we observed a trend of association for PPARG rs310746 (P value = 0.066; OR, 1.17). The combined overall Mantel-Haenszel meta-analysis of all the cohorts included in the present study revealed that PPARG rs310746 remained associated with SSc with a nominal non-genome-wide significant P value (PMH = 5.00 × 10-7; OR, 1.25). No evidence of association was observed for CHRNA9 rs6832151 either in the replication phase or in the overall pooled analysis.<p></p> Conclusion: Our results suggest a role of PPARG gene in the development of SSc

Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals

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ABSTRACT. Objective. Interferon (IFN) regulatory factors (IRF) are transcriptional mediators of IFN-induced signaling pathways and are involved in immune response. We have analyzed for the first time the association of 2 IRF5 gene variants in the susceptibility to giant cell arteritis (GCA). Methods. Two hundred twenty patients with biopsy-proven GCA and 520 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the IRF5 rs2004640 and for the IRF5 CGGGG insertion/deletion polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification, followed by an ABI3100 sequencer, respectively. Results. A genotyping rate of 96% was achieved in this series of GCA patients. No significant differences were found in the genotype distribution between GCA patients and controls for both IRF5 gene variants. In this regard, similar genotype frequencies were found in GCA patients and controls. No significant differences were observed when GCA patients were stratified according to the presence of specific clinical features of the disease such as polymyalgia rheumatica or severe ischemic complications. Conclusion. Our results showed no association of IRF5 rs2004640 and CGGGG insertion/deletion polymorphisms in the susceptibility to and clinical expression of GCA. (First Release Nov 15 2009

Tocilizumab in refractory Caucasian Takayasu's arteritis : a multicenter study of 54 patients and literature review

Objective: To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu's arteritis (TAK) in clinical practice. Methods: A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZ) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZ) was performed. Results: The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5-50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0-31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5-50.0) to 5.0 (0.0-5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0-14.0) months. Twenty-three (42.6%) patients were on TCZ and 31 (57.4%) on TCZ: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZ were younger [38.0 (27.0-46.0) versus 45.0 (38.0-57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0-38.0) versus 6.0 (1.0-23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7-5.6) versus 1.3 (0.3-3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal. Conclusion: TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin

Influence of the IL6 Gene in Susceptibility to Systemic Sclerosis

Contains fulltext : 108354.pdf (publisher's version ) (Closed access)OBJECTIVE: Systemic sclerosis (SSc) is a genetically complex autoimmune disease; the genetic component has not been fully defined. Interleukin 6 (IL-6) plays a crucial role in immunity and fibrosis, both key aspects of SSc. We investigated the influence of IL6 gene in the susceptibility and phenotype expression of SSc. METHODS: We performed a large metaanalysis including a total of 2749 cases and 3189 controls from 6 white populations (Germany, The Netherlands, Norway, Spain, Sweden, and United Kingdom). Three IL6 single-nucleotide polymorphisms (SNP; rs2069827, rs1800795, and rs2069840) were selected by SNP tagging and genotyped using TaqMan((R)) allele discrimination technology. RESULTS: Individual SNP metaanalysis showed no evidence of association of the 3 IL6 genetic variants with the global disease. Phenotype analyses revealed a significant association between the minor allele of rs2069840 and the limited cutaneous SSc clinical form (Bonferroni p = 0.036, OR 1.14, 95% CI 1.04-1.25). A trend of association between the minor allele of the rs1800795 and the diffuse cutaneous SSc clinical form was also evident (Bonferroni p = 0.072, OR 0.86, 95% CI 0.77-0.96). In the IL6 allelic combination analyses, the GGC allelic combination rs2069827-rs1800795-rs2069840 showed an association with overall SSc (Bonferroni p = 0.016, OR 1.13, 95% CI 1.04-1.23). CONCLUSION: Our results suggest that the IL6 gene may influence the development of SSc and its progression