Contribution of Telomere Length to Systemic Sclerosis Onset: A Mendelian Randomization Study.

Although previous studies have suggested a relationship between telomere shortening and systemic sclerosis (SSc), the association between these two traits remains poorly understood. The objective of this study was to assess the causal relationship between telomere length in leukocytes (LTL) and SSc using the two-sample Mendelian randomization approach, with the genome-wide association study data for both LTL and SSc. The results of inverse-variance weighted regression (OR = 0.716 [95% CI 0.528-0.970], p = 0.031) and the Mendelian randomization pleiotropy residual sum and outlier method (OR = 0.716 [95% CI 0.563-0.911], p = 0.035) indicate an association between telomere length and SSc. Specifically, longer genetically predicted LTL is associated with a reduced risk of SSc. Sensitivity tests highlight the significant roles of the variants rs10936599 and rs2736100 annotated to the TERC and TERT genes, respectively. Our findings suggest an influence of telomere length in leukocytes on the development of SSc.

The Effect of Body Fat Distribution on Systemic Sclerosis.

Obesity contributes to a chronic proinflammatory state, which is a known risk factor to develop immune-mediated diseases. However, its role in systemic sclerosis (SSc) remains to be elucidated. Therefore, we conducted a two-sample mendelian randomization (2SMR) study to analyze the effect of three body fat distribution parameters in SSc. As instrumental variables, we used the allele effects described for single nucleotide polymorphisms (SNPs) in different genome-wide association studies (GWAS) for SSc, body mass index (BMI), waist-to-hip ratio (WHR) and WHR adjusted for BMI (WHRadjBMI). We performed local (pHESS) and genome-wide (LDSC) genetic correlation analyses between each of the traits and SSc and we applied several Mendelian randomization (MR) methods (i.e., random effects inverse-variance weight, MR-Egger regression, MR pleiotropy residual sum and outlier method and a multivariable model). Our results show no genetic correlation or causal relationship between any of these traits and SSc. Nevertheless, we observed a negative causal association between WHRadjBMI and SSc, which might be due to the effect of gastrointestinal complications suffered by the majority of SSc patients. In conclusion, reverse causality might be an especially difficult confounding factor to define the effect of obesity in the onset of SSc.

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.

Clinical characteristics and outcome of Spanish patients with ANCA-associated vasculitides: Impact of the vasculitis type, ANCA specificity, and treatment on mortality and morbidity.

The aim of this study was to describe the clinical characteristics of ANCA-associated vasculitides (AAV) at presentation, in a wide cohort of Spanish patients, and to analyze the impact of the vasculitis type, ANCA specificity, prognostic factors, and treatments administered at diagnosis, in the outcome.A total of 450 patients diagnosed between January 1990 and January 2014 in 20 Hospitals from Spain were included. Altogether, 40.9% had granulomatosis with polyangiitis (GPA), 37.1% microscopic polyangiitis (MPA), and 22% eosinophilic granulomatosis with polyangiitis (EGPA). The mean age at diagnosis was 55.6 ±â€Š17.3 years, patients with MPA being significantly older (P < 0.001). Fever, arthralgia, weight loss, respiratory, and ear-nose-throat (ENT) symptoms, were the most common at disease onset. ANCAs tested positive in 86.4% of cases: 36.2% C-ANCA-PR3 and 50.2% P-ANCA-MPO. P-ANCA-MPO was significantly associated with an increased risk for renal disease (OR 2.6, P < 0.001) and alveolar hemorrhage (OR 2, P = 0.010), while C-ANCA-PR3 was significantly associated with an increased risk for ENT (OR 3.4, P < 0.001) and ocular involvement (OR 2.3, P = 0.002). All patients received corticosteroids (CS) and 74.9% cyclophosphamide (CYC). The median follow-up was 82 months (IQR 100.4). Over this period 39.9% of patients suffered bacterial infections and 14.6% opportunistic infections, both being most prevalent in patients with high-cumulated doses of CYC and CS (P < 0.001). Relapses were recorded in 36.4% of cases with a mean rate of 2.5 ±â€Š2.3, and were more frequent in patients with C-ANCA-PR3 (P = 0.012). The initial disease severity was significantly associated with mortality but not with the occurrence of relapses. One hundred twenty-nine (28.7%) patients (74 MPA, 41 GPA, 14 EGPA) died. The mean survival was 58 months (IQR 105) and was significantly lower for patients with MPA (P < 0.001). Factors independently related to death were renal involvement (P = 0.010), cardiac failure (P = 0.029) and age over 65 years old (P < 0.001) at disease onset, and bacterial infections (P < 0.001). An improved outcome with significant decrease in mortality and treatment-related morbidity was observed in patients diagnosed after 2000, and was related to the implementation of less toxic regimens adapted to the disease activity and stage, and a drastic reduction in the cumulated CYC and CS dose.

Influence of the STAT3 genetic variants in the susceptibility to psoriatic arthritis and Behcet's disease.

OBJECTIVE: Signal-transducer and activator of transcription protein 3 (STAT3) gene encodes a transducer and transcription factor that plays an important role in many cellular processes such as cell growth, apoptosis and immune response. Several STAT3 genetic variants have been associated to different autoimmune diseases. Our aim was to reveal the possible STAT3 influence in other immune-mediated diseases such as psoriatic arthritis (PsA) and Behcet disease (BD). METHODS: The STAT3 rs744166 and rs2293152 polymorphisms were genotyped using predesigned TaqMan® assays in a total of 335 PsA patients, 217 BD patients, and 1844 ethnically matched healthy controls of Spanish Caucasian origin. RESULTS: A statistically significant association of the STAT3 rs744166(∗)G allele with PsA was observed (P-value=1.36×10(-3), OR 1.35). The detected effect was more evident when the rs744166(∗)GG homozygote frequencies were compared between PsA patients and controls (genotype P-value=9.77×10(-5), OR 1.82). In contrast, the allele and genotypic distributions of rs744166 polymorphism showed no significant differences between patients with BD and control subjects (allelic P-value=0.80, OR 1.03). Additionally, no evidence of association was detected between the rs2293152 genetic variant and both studied diseases. CONCLUSION: Our results suggest for the first time that the STAT3 gene might be involved in PsA but not in Behcet's disease predisposition.

Association study of genetic variants of pro-inflammatory chemokine and cytokine genes in systemic lupus erythematosus.

BACKGROUND: Several lines of evidence suggest that chemokines and cytokines play an important role in the inflammatory development and progression of systemic lupus erythematosus. The aim of this study was to evaluate the relevance of functional genetic variations of RANTES, IL-8, IL-1alpha, and MCP-1 for systemic lupus erythematosus. METHODS: The study was conducted on 500 SLE patients and 481 ethnically matched healthy controls. Genotyping of polymorphisms in the RANTES, IL-8, IL-1alpha, and MCP-1 genes were performed using a real-time polymerase chain reaction (PCR) system with pre-developed TaqMan allelic discrimination assay. RESULTS: No significant differences between SLE patients and healthy controls were observed when comparing genotype, allele or haplotype frequencies of the RANTES, IL-8, IL-1alpha, and MCP-1 polymorphisms. In addition, no evidence for association with clinical sub-features of SLE was found. CONCLUSION: These results suggest that the tested functional variation of RANTES, IL-8, IL-1alpha, and MCP-1 genes do not confer a relevant role in the susceptibility or severity of SLE in the Spanish population.

Analysis of a GT microsatellite in the promoter of the foxp3/scurfin gene in autoimmune diseases.

The aim of this study was to assess the possible association of the functional (GT)(n) microsatellite polymorphism in the FOXP3 gene with predisposition to several autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ulcerative colitis (UC), Crohn's disease, and celiac disease. We analyzed a case-control cohort composed of 231 SLE patients, 293 RA patients, 528 inflammatory bowel disease (354 Crohn's disease patients and 260 UC patients) patients, 103 celiac disease patients, and 274 healthy controls ethnically matched. Genotyping of (GT)(n) microsatellite was performed by polymerase chain reaction (PCR)-based method combined with fluorescent technology. We found no evidence for association of this polymorphism between controls and these autoimmune disease patients. Additionally, no differences in the genotype and allele distribution were found when patients were stratified according to clinical manifestation. The (GT)(n) microsatellite of the FOXP3 gene may not play a relevant role in the susceptibility to SLE, RA, inflammatory bowel disease, and celiac disease in our population.

Analysis of a functional BTNL2 polymorphism in type 1 diabetes, rheumatoid arthritis, and systemic lupus erythematosus.

The aim of this study was to test whether the functional variant rs2076530 of the BTNL2 gene confers susceptibility to the autoimmune diseases type 1 diabetes (T1D), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE). Our study populations consisted of 326 patients with T1D and 351 healthy subjects, 808 patients with RA and 1137 healthy controls, and 372 patients with SLE and 280 healthy controls. Genotyping of the BTNL2 gene rs2076530 polymorphism was performed by real-time polymerase chain reaction technology, using the TaqMan 5'-allele discrimination assay. We observed statistically significant differences in the distribution of BTNL2rs2076530 alleles between patients with T1D, RA, and SLE and healthy controls (p=0.0035, 0.000003, and 0.00002, respectively), but in two divergent ways: the G allele was associated with T1D and RA, and the A allele was associated with SLE. However, the polymorphism exhibited strong linkage disequilibrium with HLA DQB1-DRB1 haplotypes previously identified as predisposing to the diseases. When the BTNL2 polymorphism was tested conditional on HLA DQB1-DRB1haplotypes, the BTNL2 effect was no longer significant in all three study populations. The BTNL2 rs2076530 polymorphism is associated with T1D, RA, and SLE because of its strong linkage disequalibrium with predisposing HLA DQB1-DRB1 haplotypes in Caucasian populations.