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Gene-level analysis of ImmunoChip or genome-wide association studies (GWAS) data has not been previously reported for systemic sclerosis (SSc, scleroderma). The objective of this study was to analyze genetic susceptibility loci in SSc at the gene level and to determine if the detected associations were shared in African-American and White populations, using data from ImmunoChip and GWAS genotyping studies. The White sample included 1833 cases and 3466 controls (956 cases and 2741 controls from the US and 877 cases and 725 controls from Spain) and the African American sample, 291 cases and 260 controls. In both Whites and African Americans, we performed a gene-level analysis that integrates association statistics in a gene possibly harboring multiple SNPs with weak effect on disease risk, using Versatile Gene-based Association Study (VEGAS) software. The SNP-level analysis was performed using PLINK v.1.07. We identified 4 novel candidate genes (STAT1, FCGR2C, NIPSNAP3B, and SCT) significantly associated and 4 genes (SERBP1, PINX1, TMEM175 and EXOC2) suggestively associated with SSc in the gene level analysis in White patients. As an exploratory analysis we compared the results on Whites with those from African Americans. Of previously established susceptibility genes identified in Whites, only TNFAIP3 was significant at the nominal level (p = 6.13x10-3) in African Americans in the gene-level analysis of the ImmunoChip data. Among the top suggestive novel genes identified in Whites based on the ImmunoChip data, FCGR2C and PINX1 were only nominally significant in African Americans (p = 0.016 and p = 0.028, respectively), while among the top novel genes identified in the gene-level analysis in African Americans, UNC5C (p = 5.57x10-4) and CLEC16A (p = 0.0463) were also nominally significant in Whites. We also present the gene-level analysis of SSc clinical and autoantibody phenotypes among Whites. Our findings need to be validated by independent studies, particularly due to the limited sample size of African Americans.
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População Negra/genética , Estudo de Associação Genômica Ampla , Escleroderma Sistêmico/genética , População Branca/genética , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In the article by Jacobe et al published in the November 2014 issue of Arthritis & Rheumatology (pages 3170-3177), a row listing the (nonexistent) allele DQA1*03:00 was inadvertently included in Tables 3, 5, and 6, as the result of a typographical error.
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OBJECTIVE: To examine the demographic and clinical characteristics of systemic sclerosis (SSc) patients without antinuclear antibodies (ANA) compared to ANA-positive patients. METHODS: SSc patients enrolled in the Scleroderma Family Registry and DNA Repository were included. Relevant demographic and clinical data were entered by participating sites or obtained by chart review. ANA and SSc-related antibodies were determined in all investigated patients using commercially available kits at our laboratories. RESULTS: This study included 3249 patients, of whom 208 (6.4%) were ANA negative. The proportion of male patients was higher in the ANA-negative group (OR = 1.65; p = 0.008). ANA-negative patients experienced less vasculopathic manifestations of SSc. The percent predicted diffusing capacity of carbon monoxide (DLCO) was higher in ANA-negative patients (p = 0.03). Pulmonary arterial hypertension (PAH) per right heart catheterization was less common in the ANA-negative group (OR = 0.28; p = 0.03). Furthermore, patients with negative ANA had a lower prevalence of telangiectasias and digital ulcers/pits (OR = 0.59, p = 0.03 and OR = 0.38, p = 0.01, respectively). Although diffuse cutaneous involvement was more common, the modified Rodnan Skin Score (mRSS) was lower in the ANA-negative group (2.4 points lower, p = 0.05). Furthermore, they experienced more malabsorption (p = 0.05). There was no difference in the frequency of pulmonary fibrosis or scleroderma renal crisis. All-cause mortality was not different between the 2 groups (p = 0.28). CONCLUSIONS: In conclusion, the results of this study suggest that SSc patients who are ANA negative constitute a distinct subset of SSc with less vasculopathy (less PAH, digital ulcers, and fewer telangiectasias), a greater proportion of males, and possibly, more frequent lower gastrointestinal involvement.
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Anticorpos Antinucleares/imunologia , Escleroderma Sistêmico/imunologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão Pulmonar/etiologia , Nefropatias/etiologia , Pulmão/fisiopatologia , Síndromes de Malabsorção/etiologia , Masculino , Pessoa de Meia-Idade , Capacidade de Difusão Pulmonar , Fibrose Pulmonar/etiologia , Estudos Retrospectivos , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/fisiopatologia , Fatores Sexuais , Úlcera Cutânea/etiologia , Telangiectasia/etiologiaRESUMO
OBJECTIVE: To determine the HLA class I and class II alleles of the human major histocompatibility complex showing an association with morphea (localized scleroderma) in the Morphea in Adults and Children (MAC) cohort, using a nested case-control association study. METHODS: Patients with morphea were identified from the MAC cohort, and matched controls were obtained from the National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases Scleroderma Family Registry and DNA Repository and from the Division of Rheumatology at the University of Texas Health Science Center at Houston. HLA class II genotyping and single-strand conformational polymorphism typing were performed to identify HLA-A, B, and C alleles. Associations between HLA class I and class II alleles and morphea, as well as its subphenotypes, were determined. RESULTS: Two hundred eleven patients with morphea and 726 matched controls were available for HLA class I typing, and 158 patients with morphea and 1,008 matched controls were available for HLA class II typing. The strongest associations were found with DRB1*04:04 (odds ratio [OR] 2.3, 95% confidence interval [95% CI] 1.4-4.0, P = 0.002), and HLA-B*37 conferred the highest OR among the class I alleles (OR 3.2, 95% CI 1.5-6.5, P = 0.001). Comparison of the risk allele profile in this cohort with the risk alleles previously identified in patients with systemic sclerosis, determined using the same methods and same control population, revealed one allele in common, DRB*04:04. CONCLUSION: These results demonstrate that specific HLA class I and class II alleles are associated with morphea and are also likely to be associated with generalized and linear subtypes of morphea. The morphea-associated alleles are different from those found in scleroderma, suggesting that morphea is immunogenetically distinct. Risk alleles in morphea are also associated with conditions such as rheumatoid arthritis (RA) and other autoimmune conditions. Population-based studies have indicated that patients with RA have an increased risk of morphea, and therefore a common susceptibility allele may be implicated.
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Alelos , Genes MHC da Classe II/genética , Genes MHC Classe I/genética , Predisposição Genética para Doença/genética , Esclerodermia Localizada/genética , Adolescente , Adulto , Anticorpos Antinucleares/sangue , Estudos de Casos e Controles , Criança , Estudos de Coortes , Feminino , Frequência do Gene/genética , Genótipo , Cadeias HLA-DRB1/genética , Humanos , Masculino , Sistema de Registros , Fatores de Risco , Esclerodermia Localizada/sangue , Adulto JovemRESUMO
In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci.
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Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 3/genética , Loci Gênicos , Predisposição Genética para Doença , Escleroderma Sistêmico/genética , Alelos , Proteína 5 Relacionada à Autofagia , Proteínas de Transporte/genética , Estudos de Casos e Controles , RNA Helicases DEAD-box/genética , Endodesoxirribonucleases/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Antígenos HLA/genética , Humanos , Subunidade p35 da Interleucina-12/genética , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Procedimentos Analíticos em Microchip , Proteínas Associadas aos Microtúbulos/genética , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas/genética , Fatores de Risco , População Branca/genéticaRESUMO
OBJECTIVE: To evaluate the prognostic significance of baseline electrocardiogram (ECG) abnormalities in a multiethnic cohort of patients with early systemic sclerosis (SSc) and to determine the serological, clinical, and echocardiogram correlates of ECG findings. METHODS: SSc patients with disease duration of≤5 years were enrolled in the GENISOS (Genetics versus Environment in Scleroderma Outcome Study) cohort. At the first visit, a standard 12 lead ECG was obtained along with demographic information, clinical data, and autoantibodies. The results of echocardiograms were also recorded. All ECGs were interpreted by a cardiologist unaware of the patients' clinical data. RESULTS: Of 265 SSc patients with average disease duration at enrollment of 2.5 years, 140 (52.8%) had abnormal ECG findings. These findings were not associated with SSc disease type or autoantibody profile but were associated with more severe heart and lung involvement. A total of 75 patients (28.3%) died over a follow up time of 9.9 years. Complete right bundle branch block (± left anterior hemiblock) on ECG, present in 7 (2.6%) patients, predicted a higher risk of mortality (HR: 5.3; 95% CI: 2.1 to 13.4; p<0.001). The predictive significance of right bundle branch block was independent of age at enrollment, gender, ethnicity and risk factors for coronary artery disease. CONCLUSION: ECG abnormalities are common in patients with early SSc and are associated with the severity of lung and heart involvement. Right bundle branch block is an independent predictor of mortality, and should be considered a marker of disease severity in SSc.
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Bloqueio de Ramo/complicações , Escleroderma Sistêmico/diagnóstico , Escleroderma Sistêmico/mortalidade , Estudos de Coortes , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/complicaçõesRESUMO
IMPORTANCE: Small studies have implicated the association of specific autoantibodies with morphea subtype or severity, but no large-scale studies have been conducted. This prospective case-control study confirmed the presence of antinuclear antibodies (ANAs) and other autoantibodies in morphea but found they are of limited significance. OBJECTIVE: To determine the prevalence of ANAs, extractable nuclear antigens such as antihistone antibodies (AHAs), and anti-single-stranded DNA antibodies (ssDNA abs) in patients with morphea vs a healthy control population and their association with clinical measures of morphea severity. DESIGN, SETTING, AND PARTICIPANTS: Nested case-control study, conducted at the University of Texas Southwestern Medical Center, Dallas, and University of Texas Health Science Center, Houston. Study participants included individuals enrolled in the Morphea in Adults and Children (MAC) cohort and Scleroderma Family Registry and DNA Repository. MAIN OUTCOMES AND MEASURES: Prevalence of ANAs, AHAs, ssDNA abs in patients with morphea vs matched controls and association of the presence of autoantibodies with clinical indicators of morphea severity. RESULTS: The prevalence of ANAs, AHAs, and ssDNA abs in patients with morphea was 34%, 12%, and 8%, respectively. Antinuclear antibodies and AHAs, but not ssDNA abs, were present more frequently in cases than in controls. There was no difference in ANA prevalence among morphea subtypes. Among patients with linear morphea, the presence of autoantibodies was associated with clinical indicators of severe morphea including functional limitation (ssDNA ab, P = .005; and AHA, P = .006), extensive body surface area involvement (ssDNA ab, P = .01; and ANA, P = .005), and higher skin scores (ANA, P = .004). The presence of autoantibodies was not associated with clinical measures of morphea activity. CONCLUSIONS AND RELEVANCE: Our results demonstrate that ANAs and AHAs are more prevalent among patients with morphea but are of limited clinical utility except in linear morphea, where their presence, although infrequent, is associated with greater lesion burden and functional impairment.
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Anticorpos Antinucleares/imunologia , Autoanticorpos/imunologia , DNA de Cadeia Simples/imunologia , Histonas/imunologia , Esclerodermia Localizada/imunologia , Adolescente , Adulto , Fatores Etários , Superfície Corporal , Estudos de Casos e Controles , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Índice de Gravidade de DoençaRESUMO
Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are two archetypal systemic autoimmune diseases which have been shown to share multiple genetic susceptibility loci. In order to gain insight into the genetic basis of these diseases, we performed a pan-meta-analysis of two genome-wide association studies (GWASs) together with a replication stage including additional SSc and SLE cohorts. This increased the sample size to a total of 21,109 (6835 cases and 14,274 controls). We selected for replication 19 SNPs from the GWAS data. We were able to validate KIAA0319L (P = 3.31 × 10(-11), OR = 1.49) as novel susceptibility loci for SSc and SLE. Furthermore, we also determined that the previously described SLE susceptibility loci PXK (P = 3.27 × 10(-11), OR = 1.20) and JAZF1 (P = 1.11 × 10(-8), OR = 1.13) are shared with SSc. Supporting these new discoveries, we observed that KIAA0319L was overexpressed in peripheral blood cells of SSc and SLE patients compared with healthy controls. With these, we add three (KIAA0319L, PXK and JAZF1) and one (KIAA0319L) new susceptibility loci for SSc and SLE, respectively, increasing significantly the knowledge of the genetic basis of autoimmunity.
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Predisposição Genética para Doença , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lúpus Eritematoso Sistêmico/genética , Proteínas de Neoplasias/genética , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Escleroderma Sistêmico/genética , Estudos de Casos e Controles , Proteínas Correpressoras , Proteínas de Ligação a DNA , Loci Gênicos , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular , Reprodutibilidade dos Testes , Fatores de Risco , Escleroderma Sistêmico/imunologiaRESUMO
OBJECTIVE: To examine the predictive significance of 2 pneumoproteins, surfactant protein D (SP-D) and CC-chemokine ligand 18 (CCL18), for the course of systemic sclerosis (SSc)-related interstitial lung disease. METHODS: The pneumoproteins were determined in the baseline plasma samples of 266 patients with early SSc enrolled in the GENISOS observational cohort. They also were measured in 83 followup patient samples. Pulmonary function tests were obtained annually. The primary outcome was decline in forced vital capacity (FVC percentage predicted) over time. The predictive significance for longterm change in FVC was investigated by a joint analysis of longitudinal measurements (sequentially obtained FVC percentage predicted) and survival data. RESULTS: SP-D and CCL18 levels were both higher in patients with SSc than in matched controls (p < 0.001 and p = 0.015, respectively). Baseline SP-D levels correlated with lower concomitantly obtained FVC (r = -0.27, p < 0.001), but did not predict the short-term decline in FVC at 1 year followup visit or its longterm decline rate. CCL18 showed a significant correlation with steeper short-term decline in FVC (p = 0.049), but was not a predictor of its longterm decline rate. Similarly, a composite score of SP-D and CCL18 was a significant predictor of short-term decline in FVC but did not predict its longterm decline rate. Further, the longitudinal change in these 2 pneumoproteins did not correlate with the concomitant percentage change in FVC. CONCLUSION: SP-D correlated with concomitantly obtained FVC, while CCL18 was a predictor of short-term decline in FVC. However, neither SP-D nor CCL18 was a longterm predictor of FVC course in patients with early SSc.
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Quimiocinas CC/sangue , Doenças Pulmonares Intersticiais/sangue , Proteína D Associada a Surfactante Pulmonar/sangue , Escleroderma Sistêmico/sangue , Adulto , Idoso , Progressão da Doença , Feminino , Humanos , Doenças Pulmonares Intersticiais/etiologia , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Testes de Função Respiratória , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/fisiopatologia , Capacidade Vital/fisiologiaRESUMO
OBJECTIVE: To evaluate whether the systemic sclerosis (SSc)-associated IRAK1 non-synonymous single-nucleotide polymorphism rs1059702 is responsible for the Xq28 association with SSc or whether there are other independent signals in the nearby methyl-CpG-binding protein 2 gene (MECP2). METHODS: We analysed a total of 3065 women with SSc and 2630 unaffected controls from five independent Caucasian cohorts. Four tag single-nucleotide polymorphisms of MECP2 (rs3027935, rs17435, rs5987201 and rs5945175) and the IRAK1 variant rs1059702 were genotyped using TaqMan predesigned assays. A meta-analysis including all cohorts was performed to test the overall effect of these Xq28 polymorphisms on SSc. RESULTS: IRAK1 rs1059702 and MECP2 rs17435 were associated specifically with diffuse cutaneous SSc (PFDR=4.12×10(-3), OR=1.27, 95% CI 1.09 to 1.47, and PFDR=5.26×10(-4), OR=1.30, 95% CI 1.14 to 1.48, respectively), but conditional logistic regression analysis showed that the association of IRAK1 rs1059702 with this subtype was explained by that of MECP2 rs17435. On the other hand, IRAK1 rs1059702 was consistently associated with presence of pulmonary fibrosis (PF), because statistical significance was observed when comparing SSc patients PF+ versus controls (PFDR=0.039, OR=1.30, 95% CI 1.07 to 1.58) and SSc patients PF+ versus SSc patients PF- (p=0.025, OR=1.26, 95% CI 1.03 to 1.55). CONCLUSIONS: Our data clearly suggest the existence of two independent signals within the Xq28 region, one located in IRAK1 related to PF and another in MECP2 related to diffuse cutaneous SSc, indicating that both genes may have an impact on the clinical outcome of the disease.
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Cromossomos Humanos X/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Escleroderma Sistêmico/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Desequilíbrio de Ligação , Proteína 2 de Ligação a Metil-CpG/genética , Polimorfismo de Nucleotídeo Único , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/genética , Esclerodermia Difusa/genética , Escleroderma Sistêmico/complicaçõesRESUMO
OBJECTIVE: The interleukin 2 (IL-2) and interleukin 21 (IL-21) locus at chromosome 4q27 has been associated with several autoimmune diseases, and both genes are related to immune system functions. The aim of this study was to evaluate the role of the IL-2/IL-21 locus in systemic sclerosis (SSc). PATIENTS AND METHODS: The case control study included 4493 SSc Caucasian patients and 5856 healthy controls from eight Caucasian populations (Spain, Germany, The Netherlands, USA, Italy, Sweden, UK and Norway). Four single nucleotide polymorphisms (rs2069762, rs6822844, rs6835457 and rs907715) were genotyped using TaqMan allelic discrimination assays. RESULTS: We observed evidence of association of the rs6822844 and rs907715 variants with global SSc (pc=6.6E-4 and pc=7.2E-3, respectively). Similar statistically significant associations were observed for the limited cutaneous form of the disease. The conditional regression analysis suggested that the most likely genetic variation responsible for the association was the rs6822844 polymorphism. Consistently, the rs2069762A-rs6822844T-rs6835457G-rs907715T allelic combination showed evidence of association with SSc and limited cutaneous SSc subtype (pc=1.7E-03 and pc=8E-4, respectively). CONCLUSIONS: These results suggested that the IL-2/IL-21 locus influences the genetic susceptibility to SSc. Moreover, this study provided further support for the IL-2/IL-21 locus as a common genetic factor in autoimmune diseases.
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Interleucina-2/genética , Interleucinas/genética , Escleroderma Sistêmico/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Modelos Logísticos , Masculino , Polimorfismo de Nucleotídeo Único , Esclerodermia Difusa/etnologia , Esclerodermia Difusa/genética , Esclerodermia Limitada/etnologia , Esclerodermia Limitada/genética , Escleroderma Sistêmico/etnologia , População Branca/genéticaRESUMO
INTRODUCTION: A recent genome-wide association study in European systemic sclerosis (SSc) patients identified three loci (PSORS1C1, TNIP1 and RHOB) as novel genetic risk factors for the disease. The aim of this study was to replicate the previously mentioned findings in a large multicentre independent SSc cohort of Caucasian ancestry. METHODS: 4389 SSc patients and 7611 healthy controls from different European countries and the USA were included in the study. Six single nucleotide polymorphisms (SNP): rs342070, rs13021401 (RHOB), rs2233287, rs4958881, rs3792783 (TNIP1) and rs3130573 (PSORS1C1) were analysed. Overall significance was calculated by pooled analysis of all the cohorts. Haplotype analyses and conditional logistic regression analyses were carried out to explore further the genetic structure of the tested loci. RESULTS: Pooled analyses of all the analysed SNPs in TNIP1 revealed significant association with the whole disease (rs2233287 p(MH)=1.94×10(-4), OR 1.19; rs4958881 p(MH)=3.26×10(-5), OR 1.19; rs3792783 p(MH)=2.16×10(-4), OR 1.19). These associations were maintained in all the subgroups considered. PSORS1C1 comparison showed association with the complete set of patients and all the subsets except for the anti-centromere-positive patients. However, the association was dependent on different HLA class II alleles. The variants in the RHOB gene were not associated with SSc or any of its subsets. CONCLUSIONS: These data confirmed the influence of TNIP1 on an increased susceptibility to SSc and reinforced this locus as a common autoimmunity risk factor.
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Proteínas de Ligação a DNA/genética , Proteínas/genética , Escleroderma Sistêmico/epidemiologia , Escleroderma Sistêmico/genética , Proteína rhoB de Ligação ao GTP/genética , Europa (Continente)/epidemiologia , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , População Branca/genética , População Branca/estatística & dados numéricosRESUMO
Systemic sclerosis (SSc) is complex autoimmune disease affecting the connective tissue; influenced by genetic and environmental components. Recently, we performed the first successful genome-wide association study (GWAS) of SSc. Here, we perform a large replication study to better dissect the genetic component of SSc. We selected 768 polymorphisms from the previous GWAS and genotyped them in seven replication cohorts from Europe. Overall significance was calculated for replicated significant SNPs by meta-analysis of the replication cohorts and replication-GWAS cohorts (3237 cases and 6097 controls). Six SNPs in regions not previously associated with SSc were selected for validation in another five independent cohorts, up to a total of 5270 SSc patients and 8326 controls. We found evidence for replication and overall genome-wide significance for one novel SSc genetic risk locus: CSK [P-value = 5.04 × 10(-12), odds ratio (OR) = 1.20]. Additionally, we found suggestive association in the loci PSD3 (P-value = 3.18 × 10(-7), OR = 1.36) and NFKB1 (P-value = 1.03 × 10(-6), OR = 1.14). Additionally, we strengthened the evidence for previously confirmed associations. This study significantly increases the number of known putative genetic risk factors for SSc, including the genes CSK, PSD3 and NFKB1, and further confirms six previously described ones.
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Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único , Proteínas Tirosina Quinases/genética , Escleroderma Sistêmico/genética , Proteína Tirosina Quinase CSK , Estudos de Coortes , Europa (Continente) , Seguimentos , Genótipo , Humanos , Fatores Reguladores de Interferon/genética , Metanálise como Assunto , Subunidade p50 de NF-kappa B/genética , Razão de Chances , Fatores de Risco , beta Carioferinas/genética , Quinases da Família srcRESUMO
OBJECTIVE: Independent replication with large cohorts and metaanalysis of genetic associations are necessary to validate genetic susceptibility factors. The known tumor necrosis factor (ligand) superfamily, member 4 gene (TNFSF4) systemic lupus erythematosus (SLE) risk locus has been found to be associated with systemic sclerosis (SSc) in 2 studies, but with discrepancies between them for genotype-phenotype correlation. Our objective was to validate TNFSF4 association with SSc and determine the subset with the higher risk. METHODS: Known SLE and SSc TNFSF4 susceptibility variants (rs2205960, rs1234317, rs12039904, rs10912580, and rs844648) were genotyped in 1031 patients with SSc and 1014 controls of French white ancestry. Genotype-phenotype association analysis and meta analysis of available data were performed, providing a population study of 4989 patients with SSc and 4661 controls, all of European white ancestry. RESULTS: Allelic and genotypic associations were observed for the 5 single-nucleotide polymorphisms (SNP) with the subset of patients with SSc who are positive for anticentromere antibodies (ACA) and only a trend for association with SSc and limited cutaneous SSc. Rs2205960 exhibited the strongest allelic association in ACA+ patients with SSc [p = 0.0015; OR 1.37 (1.12-1.66)], with significant intra-cohort association when compared to patients with SSc positive for ACA. Metaanalysis confirmed overall association with SSc but also raised preferential association with the ACA+ subset and strongest effect with rs2205960 [T allele p = 0.00013; OR 1.33 (1.15-1.54) and TT genotype p = 0.00046; OR 2.02 (1.36-2.98)]. CONCLUSION: We confirm TNFSF4 as an SSc susceptibility gene and rs2205960 as a putative causal variant with preferential association in the ACA+ SSc subphenotype.
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Doenças Autoimunes/genética , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Ligante OX40/genética , Escleroderma Sistêmico/epidemiologia , Escleroderma Sistêmico/genética , Adulto , Centrômero/genética , Centrômero/imunologia , Feminino , Estudos de Associação Genética/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Ligante OX40/imunologia , Fatores de Risco , Escleroderma Sistêmico/imunologia , População Branca/genéticaRESUMO
Osteopontin (OPN) is a matricellular protein with proinflammatory and profibrotic properties. Previous reports demonstrate a role for OPN in wound healing and pulmonary fibrosis. Here, we determined whether OPN levels are increased in a large cohort of patients with systemic sclerosis (SSc) and whether OPN contributes to the development of dermal fibrosis. The plasma OPN levels were increased in SSc patients, including patients with limited and diffuse disease, compared with healthy controls. Immunohistology demonstrated OPN on fibroblast-like and inflammatory cells in SSc skin and lesional skin from mice in the bleomycin (bleo)-induced dermal fibrosis model. OPN-deficient (OPN(-/-)) mice developed less dermal fibrosis compared with wild-type (WT) mice in the bleo-induced dermal fibrosis model. Additional in vivo studies have demonstrated that lesional skin from OPN(-/-)mice had fewer Mac-3-positive cells, fewer myofibroblasts, decreased transforming growth factor (TGF)-ß and genes in the TGF-ß pathway, and decreased numbers of cells expressing phosphorylated SMAD2 (pSMAD) and extracellular signal-regulated kinase. In vitro, OPN(-/-) dermal fibroblasts had decreased migratory capacity but similar phosphorylation of SMAD2 by TGF-ß. Finally, TGF-ß production by OPN-deficient macrophages was reduced compared with WT. These data demonstrate an important role for OPN in the development of dermal fibrosis and suggest that it may be a new therapeutic target in SSc.
Assuntos
Osteopontina/genética , Osteopontina/metabolismo , Escleroderma Sistêmico/fisiopatologia , Adulto , Animais , Antibióticos Antineoplásicos/toxicidade , Bleomicina/toxicidade , Células Cultivadas , Derme/citologia , Derme/fisiologia , Modelos Animais de Doenças , Feminino , Fibroblastos/citologia , Fibroblastos/fisiologia , Fibrose/patologia , Fibrose/fisiopatologia , Humanos , Macrófagos/citologia , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Escleroderma Sistêmico/induzido quimicamente , Escleroderma Sistêmico/patologia , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
OBJECTIVE: The first genome-wide association study (GWAS) of systemic sclerosis (SSc) demonstrated three non-major histocompatibility complex (MHC) susceptibility loci. The goal of this study was to investigate the impact of these gene variants on survival and severity of interstitial lung disease (ILD) in SSc. METHODS: The authors examined 1443 Caucasian SSc patients enrolled in the Genetics versus Environment In Scleroderma Outcome Study (GENISOS) and Scleroderma Family Registry (n = 914 - discovery cohort) and The Johns Hopkins Scleroderma Cohort (n = 529 - replication cohort). Forced vital capacity (FVC)% predicted was used as a surrogate for ILD severity. Five single nucleotide polymorphisms, IRF5 (rs10488631, rs12537284, rs4728142), STAT4 (rs3821236), CD247 (rs2056626) reached genome-wide significance in the SSc-GWAS and were examined in the current study. RESULTS: Overall, 15.5% of the patients had died over the follow-up period of 5.5 years. The IRF5 rs4728142 minor allele was predictive of longer survival in the discovery cohort (p = 0.021) and in the independent replication cohort (p = 0.047) and combined group (HR: 0.75, 95% CI 0.62 to 0.90, p = 0.002). The association of this SNP with survival was independent of age at disease onset, disease type and autoantibody profile (anticentromere and antitopoisomerase antibodies). The minor allele frequency of IRF5 rs4728142 was 49.4%. Moreover, IRF5 rs4728142 minor allele correlated with higher FVC% predicted at enrolment (p = 0.019). Finally, the IRF5 rs4728142 minor allele was associated with lower IRF5 transcript expression in patients and controls (p = 0.016 and p = 0.034, respectively), suggesting that the IRF5, rs4728142 SNP, may be functionally relevant. CONCLUSION: An SNP in the IRF5 promoter region (rs4728142), associated with lower IRF5 transcript levels, was predictive of longer survival and milder ILD in patients with SSc.
Assuntos
Fatores Reguladores de Interferon/genética , Polimorfismo de Nucleotídeo Único , Escleroderma Sistêmico/diagnóstico , Adulto , Idade de Início , Biomarcadores/metabolismo , Comorbidade , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Fatores Reguladores de Interferon/metabolismo , Doenças Pulmonares Intersticiais/genética , Doenças Pulmonares Intersticiais/mortalidade , Doenças Pulmonares Intersticiais/patologia , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Prognóstico , Sistema de Registros , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/mortalidade , Índice de Gravidade de Doença , Taxa de Sobrevida , Estados Unidos/epidemiologia , Capacidade VitalRESUMO
A single-nucleotide polymorphism (SNP) at the IL12RB2 locus showed a suggestive association signal in a previously published genome-wide association study (GWAS) in systemic sclerosis (SSc). Aiming to reveal the possible implication of the IL12RB2 gene in SSc, we conducted a follow-up study of this locus in different Caucasian cohorts. We analyzed 10 GWAS-genotyped SNPs in the IL12RB2 region (2309 SSc patients and 5161 controls). We then selected three SNPs (rs3790567, rs3790566 and rs924080) based on their significance level in the GWAS, for follow-up in an independent European cohort comprising 3344 SSc and 3848 controls. The most-associated SNP (rs3790567) was further tested in an independent cohort comprising 597 SSc patients and 1139 controls from the USA. After conditional logistic regression analysis of the GWAS data, we selected rs3790567 [P(MH)= 1.92 × 10(-5) odds ratio (OR) = 1.19] as the genetic variant with the firmest independent association observed in the analyzed GWAS peak of association. After the first follow-up phase, only the association of rs3790567 was consistent (P(MH)= 4.84 × 10(-3) OR = 1.12). The second follow-up phase confirmed this finding (P(χ2) = 2.82 × 10(-4) OR = 1.34). After performing overall pooled-analysis of all the cohorts included in the present study, the association found for the rs3790567 SNP in the IL12RB2 gene region reached GWAS-level significant association (P(MH)= 2.82 × 10(-9) OR = 1.17). Our data clearly support the IL12RB2 genetic association with SSc, and suggest a relevant role of the interleukin 12 signaling pathway in SSc pathogenesis.
Assuntos
Predisposição Genética para Doença/genética , Receptores de Interleucina-12/genética , Escleroderma Sistêmico/genética , População Branca/genética , Europa (Continente)/etnologia , Seguimentos , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único/genética , Estados Unidos/etnologiaRESUMO
OBJECTIVE: Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are related chronic autoimmune diseases of complex aetiology in which the interferon (IFN) pathway plays a key role. Recent studies have reported an association between IRF7 and SLE which confers a risk to autoantibody production. A study was undertaken to investigate whether the IRF7 genomic region is also involved in susceptibility to SSc and the main clinical features. METHODS: Two case-control sets of Caucasian origin from the USA and Spain, comprising a total of 2316 cases of SSc and 2347 healthy controls, were included in the study. Five single nucleotide polymorphisms (SNPs) in the PHRF1-IRF7-CDHR5 locus were genotyped using TaqMan allelic discrimination technology. A meta-analysis was performed to test the overall effect of these genetic variants on SSc. RESULTS: Four out of five analysed SNPs were significantly associated with the presence of anticentromere autoantibodies (ACA) in the patients with SSc in the combined analysis (rs1131665: p(FDR)=6.14 × 10(-4), OR=0.78; rs4963128: p(FDR)=6.14 × 10(-4), OR=0.79; rs702966: p(FDR)=3.83 × 10(-3), OR=0.82; and rs2246614: p(FDR)=3.83 × 10(-3), OR=0.83). Significant p values were also obtained when the disease was tested globally; however, the statistical significance was lost when the ACA-positive patients were excluded from the study, suggesting that these associations rely on ACA positivity. Conditional logistic regression and allelic combination analyses suggested that the functional IRF7 SNP rs1131665 is the most likely causal variant. CONCLUSIONS: The results show that variation in the IRF7 genomic region is associated with the presence of ACA in patients with SSc, supporting other evidence that this locus represents a common risk factor for autoantibody production in autoimmune diseases.
Assuntos
Anticorpos Antinucleares/sangue , Doenças Autoimunes/genética , Fator Regulador 7 de Interferon/genética , Escleroderma Sistêmico/genética , Anticorpos Antinucleares/biossíntese , Doenças Autoimunes/imunologia , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Escleroderma Sistêmico/imunologiaRESUMO
INTRODUCTION: Sumoylation is involved in nucleolus-nucleoplasm transport of DNA topoisomerase I (topo I), which may associate with changes of cellular and topo I functions. Skin fibroblasts of patients with systemic sclerosis (SSc) exhibit profibrotic cellular changes. The aims of this study were to examine the catalytic function and sumoylation of topo I in the nuclei of SSc fibroblasts, a major cell type involved in the fibrotic process. METHODS: Eleven pairs of fibroblast strains obtained from nonlesional skin biopsies of SSc patients and age/sex/ethnicity-matched normal controls were examined for catalytic function of nuclear topo I. Immunoprecipitation (IP)-Western blots were used to examine sumoylation of fibroblast topo I. Real-time quantitative RT-PCR was used to measure transcript levels of SUMO1 and COL1A2 in the fibroblasts. RESULTS: Topo I in nuclear extracts of SSc fibroblasts generally showed a significantly lower efficiency than that of normal fibroblasts in relaxing equivalent amounts of supercoiled DNA. Increased sumoylation of topo I was clearly observed in 7 of 11 SSc fibroblast strains. Inhibition of SUMO1 with SUMO1 siRNA improved the catalytic efficiency of topo I in the SSc fibroblasts. In contrast, sumoylation of recombinant topo I proteins reduced their catalytic function. CONCLUSIONS: The catalytic function of topo I was decreased in SSc fibroblasts, to which increased sumoylation of topo I may contribute.
Assuntos
Biocatálise , Núcleo Celular/enzimologia , DNA Topoisomerases Tipo I/metabolismo , Fibroblastos/enzimologia , Escleroderma Sistêmico/enzimologia , Western Blotting , Feminino , Humanos , Imuno-Histoquímica , Imunoprecipitação , Masculino , RNA Interferente Pequeno , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sumoilação , TransfecçãoRESUMO
OBJECTIVE: To investigate the association of cigarette smoking with susceptibility to systemic sclerosis (SSc) in a large, well-defined patient population. METHODS: We conducted a review of 1,379 patients with SSc enrolled in the Scleroderma Family Registry and DNA Repository and/or the Genetics versus Environment in Scleroderma Outcome Study cohort. Smoking history was obtained from chart review or via telephone interview. Patients with SSc were subsequently categorized as never smokers or ever smokers. Patients with SSc for whom smoking data were available were matched 2:1 by age, sex, ethnicity, and state of residence to control subjects, using the Behavioral Risk Factor Surveillance System. RESULTS: The majority of patients were white (74.2%), with Hispanics and blacks representing 11.3% and 9.7%, respectively. Most patients had limited cutaneous involvement (54%). For our comparative analyses, 621 patients were matched with control subjects. There was no significant difference in age, sex, ethnicity, and SSc subtype between matched versus unmatched patients. The majority of patients had never smoked (57%), while 43% of patients were classified as ever smokers. The patients with SSc did not differ from control subjects in terms of their smoking behavior (odds ratio [OR] 1.020, 95% confidence interval [95% CI] 0.839-1.240, P=0.842). Anti-topoisomerase I antibody-positive patients were more likely to be never smokers (OR 0.648, 95% CI 0.421-0.998, P=0.049), whereas no such association was observed with anticentromere and anti-RNA polymerase III antibodies. CONCLUSION: Unlike its role in rheumatoid arthritis, smoking does not confer a risk for development of SSc, although it may impact disease severity.