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1.
Artigo em Inglês | MEDLINE | ID: mdl-31199565

RESUMO

OBJECTIVE: To describe the clinical and serological manifestations of Sjögren's syndrome (SS) in ethnic groups of the United States. METHODS: Cross-sectional study of 648 patients with primary SS: 20 African-American (AA), 164 American Indian (AI), 426 European-American (EA) and 38 of other races evaluated in a multi-disciplinary sicca research clinic. RESULTS: AA subjects comprised 3.1% of the SS cohort, much lower than the percentage of AA in the State of Oklahoma (p=3.01xE-05), the United States (p=2.24E-13) or a lupus cohort at the same institution (p=4.26x10E-27). In contrast, the percentage of AI in the SS cohort (25.3%) was much higher than expected (p=3.17E-09 vs. SLE; p=6.36-26 vs. Oklahoma and p=8.14E-96 vs. USA population). The SS classification criteria were similar between AA and EA, but subjects of AI ancestry had lower rates of abnormal tear and salivary flow as well as anti-Ro/SSA and anti-La/SSB antibodies. Paradoxically, AI had higher levels of disease activity (mean±SD ESSDAI 3.77±4.78) in comparison to whites (2.90±4.12; p=0.011) and more extraglandular manifestations affecting mainly the articular and glandular domains. Meanwhile, AA patients were characterized by higher rates of hypergammaglobulinemia (OR 1.39, 95%CI 1.39-8.65, p=0.01), elevated ESR (OR 3.95, 95%CI 1.46-9.95, p=0.009), and parotid enlargement (OR 4.40, 95%CI 1.49-13.07, p=0.02). CONCLUSIONS: American Indians are affected at high rates with SS but present with few classical features, potentially preventing timely diagnosis. In contrast to SLE, SS is infrequent and not more severe amongst AA, but the triad of hypergammaglobulinemia, increased ESR and parotid enlargement warrants extra vigilance for lymphomagenesis. This article is protected by copyright. All rights reserved.

2.
Ann Rheum Dis ; 78(9): 1235-1241, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31217170

RESUMO

OBJECTIVE: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with unknown aetiology. Epstein-Barr virus (EBV) is an environmental factor associated with SLE. EBV maintains latency in B cells with frequent reactivation measured by antibodies against viral capsid antigen (VCA) and early antigen (EA). In this study, we determined whether EBV reactivation and single nucleotide polymorphisms (SNPs) in EBV-associated host genes are associated with SLE transition. METHODS: SLE patient relatives (n=436) who did not have SLE at baseline were recontacted after 6.3 (±3.9) years and evaluated for interim transitioning to SLE (≥4 cumulative American College of Rheumatology criteria); 56 (13%) transitioned to SLE prior to the follow-up visit. At both visits, detailed demographic, environmental, clinical information and blood samples were obtained. Antibodies against viral antigens were measured by ELISA. SNPs in IL10, CR2, TNFAIP3 and CD40 genes were typed by ImmunoChip. Generalised estimating equations were used to test associations between viral antibody levels and transitioning to SLE. RESULTS: Mean baseline VCA IgG (4.879±1.797 vs 3.866±1.795, p=0.0003) and EA IgG (1.192±1.113 vs 0.7774±0.8484, p=0.0236) levels were higher in transitioned compared with autoantibody negative non-transitioned relatives. Increased VCA IgG and EA IgG were associated with transitioning to SLE (OR 1.28 95% CI 1.07 to 1.53, p=0.007, OR 1.43 95% CI 1.06 to 1.93, p=0.02, respectively). Significant interactions were observed between CD40 variant rs48100485 and VCA IgG levels and IL10 variant rs3024493 and VCA IgA levels in transitioning to SLE. CONCLUSION: Heightened serologic reactivation of EBV increases the probability of transitioning to SLE in unaffected SLE relatives.

3.
EBioMedicine ; 42: 76-85, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30952617

RESUMO

BACKGROUND: Autoimmune disease prevention requires tools to assess an individual's risk of developing a specific disease. One tool is disease-associated autoantibodies, which accumulate in an asymptomatic preclinical period. However, patients sometimes exhibit autoantibodies associated with a different disease classification. When and how these alternative autoantibodies first appear remain unknown. This cross-sectional study characterizes alternative autoimmunity, and associated genetic and environmental factors, in unaffected first-degree relatives (FDRs) of patients, who exhibit increased future risk for the same disease. METHODS: Samples (n = 1321) from disease-specific autoantibody-positive (aAb+) systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and type 1 diabetes (T1D) patients; and unaffected aAb+ and autoantibody-negative (aAb-) SLE and RA FDRs were tested for SLE, RA, and T1D aAbs, as well as anti-tissue transglutaminase, anti-cardiolipin and anti-thyroperoxidase. FDR SLE and RA genetic risk scores (GRS) were calculated. FINDINGS: Alternative autoimmunity occurred in SLE patients (56%) and FDRs (57·4%), RA patients (32·6%) and FDRs (34·8%), and T1D patients (43%). Expanded autoimmunity, defined as autoantibodies spanning at least two other diseases, occurred in 18·5% of SLE patients, 16·4% of SLE FDRs, 7·8% of RA patients, 5·3% of RA FDRs, and 10·8% of T1D patients. SLE FDRs were more likely to have alternative (odds ratio [OR] 2·44) and expanded (OR 3·27) autoimmunity than RA FDRs. Alternative and expanded autoimmunity were associated with several environmental exposures. Alternative autoimmunity was associated with a higher RA GRS in RA FDRs (OR 1·41), and a higher SLE GRS in aAb+ RA FDRs (OR 1·87), but not in SLE FDRs. INTERPRETATION: Autoimmunity commonly crosses disease-specific boundaries in systemic (RA, SLE) and organ-specific (T1D) autoimmune diseases. Alternative autoimmunity is more common in SLE FDRs than RA FDRs, and is influenced by genetic and environmental factors. These findings have substantial implications for preclinical disease pathogenesis and autoimmune disease prevention studies. FUND: NIH U01AI101981, R01AR051394, U19AI082714, P30AR053483, P30GM103510, U54GM104938, U01AI101934, R01AI024717, U01AI130830, I01BX001834, & U01HG008666.


Assuntos
Artrite Reumatoide/etiologia , Autoimunidade/genética , Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/etiologia , Núcleo Familiar , Adulto , Idoso , Alelos , Artrite Reumatoide/diagnóstico , Autoanticorpos/imunologia , Meio Ambiente , Feminino , Frequência do Gene , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Especificidade de Órgãos/imunologia , Polimorfismo de Nucleotídeo Único , Fatores de Risco
4.
Cytokine ; 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30685201

RESUMO

BACKGROUND/PURPOSE: High serum interferon alpha (IFN-α) is an important heritable phenotype in systemic lupus erythematosus (SLE) which is involved in primary disease pathogenesis. High vs. low levels of IFN-α are associated with disease severity and account for some of the biological heterogeneity between SLE patients. The aim of the study was to replicate and fine-map previously detected genetic associations with serum IFN-α in SLE. METHODS: We previously undertook a case-case genome-wide association study of SLE patients stratified by ancestry and extremes of phenotype in serum IFN-α. Single nucleotide polymorphisms (SNPs) in seven loci identified in this screen were selected for follow up in a large independent cohort of 1370 SLE patients (703 European-ancestry, 432 African ancestry, and 235 Amerindian ancestry). Each ancestral background was analyzed separately, and ancestry-informative markers were used to control for ancestry and admixture. RESULTS: We find a rare haplotype spanning the promoter region of EFNA5 that is strongly associated with serum IFN-α in both African-American and European-American SLE patients (OR = 3.0, p = 3.7 × 10-6). We also find SNPs in the PPM1H, PTPRM, and NRGN regions associated with IFN-α levels in European-American, Amerindian, and African-American SLE patients respectively. Many of these associations are within regulatory regions of the gene, suggesting an impact on transcription. CONCLUSION: This study demonstrates the power of molecular sub-phenotypes to reveal genetic factors involved in complex autoimmune disease. The distinct associations observed in different ancestral backgrounds emphasize the heterogeneity of molecular pathogenesis in SLE.

5.
Hum Mol Genet ; 27(21): 3813-3824, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30085094

RESUMO

Genetic variation within the major histocompatibility complex (MHC) contributes substantial risk for systemic lupus erythematosus, but high gene density, extreme polymorphism and extensive linkage disequilibrium (LD) have made fine mapping challenging. To address the problem, we compared two association techniques in two ancestrally diverse populations, African Americans (AAs) and Europeans (EURs). We observed a greater number of Human Leucocyte Antigen (HLA) alleles in AA consistent with the elevated level of recombination in this population. In EUR we observed 50 different A-C-B-DRB1-DQA-DQB multilocus haplotype sequences per hundred individuals; in the AA sample, these multilocus haplotypes were twice as common compared to Europeans. We also observed a strong narrow class II signal in AA as opposed to the long-range LD observed in EUR that includes class I alleles. We performed a Bayesian model choice of the classical HLA alleles and a frequentist analysis that combined both single nucleotide polymorphisms (SNPs) and classical HLA alleles. Both analyses converged on a similar subset of risk HLA alleles: in EUR HLA- B*08:01 + B*18:01 + (DRB1*15:01 frequentist only) + DQA*01:02 + DQB*02:01 + DRB3*02 and in AA HLA-C*17:01 + B*08:01 + DRB1*15:03 + (DQA*01:02 frequentist only) + DQA*02:01 + DQA*05:01+ DQA*05:05 + DQB*03:19 + DQB*02:02. We observed two additional independent SNP associations in both populations: EUR rs146903072 and rs501480; AA rs389883 and rs114118665. The DR2 serotype was best explained by DRB1*15:03 + DQA*01:02 in AA and by DRB1*15:01 + DQA*01:02 in EUR. The DR3 serotype was best explained by DQA*05:01 in AA and by DQB*02:01 in EUR. Despite some differences in underlying HLA allele risk models in EUR and AA, SNP signals across the extended MHC showed remarkable similarity and significant concordance in direction of effect for risk-associated variants.

6.
Nat Commun ; 9(1): 2905, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30046115

RESUMO

Genetic variants can confer risk to complex genetic diseases by modulating gene expression through changes to the epigenome. To assess the degree to which genetic variants influence epigenome activity, we integrate epigenetic and genotypic data from lupus patient lymphoblastoid cell lines to identify variants that induce allelic imbalance in the magnitude of histone post-translational modifications, referred to herein as histone quantitative trait loci (hQTLs). We demonstrate that enhancer hQTLs are enriched on autoimmune disease risk haplotypes and disproportionately influence gene expression variability compared with non-hQTL variants in strong linkage disequilibrium. We show that the epigenome regulates HLA class II genes differently in individuals who carry HLA-DR3 or HLA-DR15 haplotypes, resulting in differential 3D chromatin conformation and gene expression. Finally, we identify significant expression QTL (eQTL) x hQTL interactions that reveal substructure within eQTL gene expression, suggesting potential implications for functional genomic studies that leverage eQTL data for subject selection and stratification.

7.
Genes Immun ; 2018 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-29904099

RESUMO

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus triggered by immune hypersensitivity to food. Herein, we tested whether genetic risk factors for known, non-allergic, immune-mediated diseases, particularly those involving autoimmunity, were associated with EoE risk. We used the high-density Immunochip platform, encoding 200,000 genetic variants for major auto-immune disease. Accordingly, 1214 subjects with EoE of European ancestry and 3734 population controls were genotyped and assessed using data directly generated or imputed from the previously published GWAS. We found lack of association of EoE with the genetic variants in the major histocompatibility complex (MHC) class I, II, and III genes and nearly all other loci using a highly powered study design with dense genotyping throughout the locus. Importantly, we identified an EoE risk locus at 16p13 with genome-wide significance (Pcombined=2.05 × 10-9, odds ratio = 0.76-0.81). This region is known to encode for the genes CLEC16A, DEXI, and CIITI, which are expressed in immune cells and esophageal epithelial cells. Suggestive EoE risk were also seen 5q23 (intergenic) and 7p15 (JAZF1). Overall, we have identified an additional EoE risk locus at 16p13 and highlight a shared and unique genetic etiology of EoE with a spectrum of immune-associated diseases.

9.
Arthritis Rheumatol ; 69(11): 2187-2192, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28692793

RESUMO

OBJECTIVE: Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE) are related by clinical and serologic manifestations as well as genetic risks. Both diseases are more commonly found in women than in men, at a ratio of ~10 to 1. Common X chromosome aneuploidies, 47,XXY and 47,XXX, are enriched among men and women, respectively, in either disease, suggesting a dose effect on the X chromosome. METHODS: We examined cohorts of SS and SLE patients by constructing intensity plots of X chromosome single-nucleotide polymorphism alleles, along with determining the karyotype of selected patients. RESULTS: Among ~2,500 women with SLE, we found 3 patients with a triple mosaic, consisting of 45,X/46,XX/47,XXX. Among ~2,100 women with SS, 1 patient had 45,X/46,XX/47,XXX, with a triplication of the distal p arm of the X chromosome in the 47,XXX cells. Neither the triple mosaic nor the partial triplication was found among the controls. In another SS cohort, we found a mother/daughter pair with partial triplication of this same region of the X chromosome. The triple mosaic occurs in ~1 in 25,000-50,000 live female births, while partial triplications are even rarer. CONCLUSION: Very rare X chromosome abnormalities are present among patients with either SS or SLE and may inform the location of a gene(s) that mediates an X dose effect, as well as critical cell types in which such an effect is operative.


Assuntos
Cromossomos Humanos X/genética , Lúpus Eritematoso Sistêmico/genética , Mosaicismo/estatística & dados numéricos , Aberrações dos Cromossomos Sexuais/estatística & dados numéricos , Síndrome de Sjogren/genética , Alelos , Teorema de Bayes , Feminino , Dosagem de Genes , Humanos , Cariótipo , Lúpus Eritematoso Sistêmico/epidemiologia , Polimorfismo de Nucleotídeo Único , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/epidemiologia , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genética , Síndrome de Sjogren/epidemiologia , Trissomia/genética , Síndrome de Turner/epidemiologia , Síndrome de Turner/genética
10.
Nat Commun ; 8: 16021, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28714469

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10-8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.

11.
PLoS Genet ; 13(6): e1006820, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28640813

RESUMO

Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.


Assuntos
2',5'-Oligoadenilato Sintetase/genética , Interferon Tipo I/genética , Locos de Características Quantitativas/genética , Síndrome de Sjogren/genética , 2',5'-Oligoadenilato Sintetase/biossíntese , Alelos , Processamento Alternativo/genética , Feminino , Regulação da Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Interferon Tipo I/metabolismo , Masculino , Síndrome de Sjogren/metabolismo , Síndrome de Sjogren/patologia , Viroses/genética , Viroses/virologia
12.
PLoS One ; 12(2): e0171193, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28234905

RESUMO

Antiviral defenses are inappropriately activated in systemic lupus erythematosus (SLE) and association between SLE and the antiviral helicase gene, IFIH1, is well established. We sought to extend the previously reported association of pathogenic soluble mediators and autoantibodies with mouse Mda5 to its human ortholog, IFIH1. To better understand the role this gene plays in human lupus, we assessed association of IFIH1 variants with soluble mediators and autoantibodies in 357 European-American SLE patients, first-degree relatives, and unrelated, unaffected healthy controls. Association between each of 135 genotyped SNPs in IFIH1 and four lupus-associated plasma mediators, IL-6, TNF-α, IFN-ß, and IP-10, were investigated via linear regression. No significant associations were found to SNPs orthologous to those identified in exon 13 of the mouse. However, outside of this region there were significant associations between IL-6 and rs76162067 (p = 0.008), as well as IP-10 and rs79711023 (p = 0.003), located in a region of IFIH1 previously shown to directly influence MDA-5 mediated IP-10 and IL-6 secretion. SLE patients and FDRs carrying the minor allele for rs79711023 demonstrated lower levels of IP-10, while only FDRs carrying the minor allele for rs76162067 demonstrated an increased level of IL-6. This would suggest that the change in IP-10 is genotypically driven, while the change in IL-6 may be reflective of SLE transition status. These data suggest that IFIH1 may contribute to SLE pathogenesis via altered inflammatory mechanisms.


Assuntos
Quimiocina CXCL10/genética , Helicase IFIH1 Induzida por Interferon/genética , Interleucina-6/genética , Lúpus Eritematoso Sistêmico/genética , Adulto , Idoso , Animais , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Mediadores da Inflamação/metabolismo , Interferon beta/genética , Camundongos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genética
13.
Nat Genet ; 49(3): 433-437, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28135245

RESUMO

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease with a strong genetic component characterized by autoantibody production and a type I interferon signature. Here we report a missense variant (g.74779296G>A; p.Arg90His) in NCF1, encoding the p47phox subunit of the phagocyte NADPH oxidase (NOX2), as the putative underlying causal variant that drives a strong SLE-associated signal detected by the Immunochip in the GTF2IRD1-GTF2I region at 7q11.23 with a complex genomic structure. We show that the p.Arg90His substitution, which is reported to cause reduced reactive oxygen species (ROS) production, predisposes to SLE (odds ratio (OR) = 3.47 in Asians (Pmeta = 3.1 × 10-104), OR = 2.61 in European Americans, OR = 2.02 in African Americans) and other autoimmune diseases, including primary Sjögren's syndrome (OR = 2.45 in Chinese, OR = 2.35 in European Americans) and rheumatoid arthritis (OR = 1.65 in Koreans). Additionally, decreased and increased copy numbers of NCF1 predispose to and protect against SLE, respectively. Our data highlight the pathogenic role of reduced NOX2-derived ROS levels in autoimmune diseases.


Assuntos
Doenças Autoimunes/genética , Predisposição Genética para Doença/genética , NADPH Oxidases/genética , Polimorfismo de Nucleotídeo Único/genética , Afro-Americanos/genética , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Humanos , Lúpus Eritematoso Sistêmico/genética , Masculino , Espécies Reativas de Oxigênio/metabolismo , Síndrome de Sjogren/genética
14.
JCI Insight ; 1(8)2016 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-27358913

RESUMO

CD4+ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren's syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and ß transcripts of single CD4+CD45RA- T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and ß sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and ß sequences enables further work toward identification of target antigens and development of novel therapies.

15.
Clin Immunol ; 168: 25-29, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27109640

RESUMO

Primary Sjögren's syndrome (pSS) has a strong female bias. We evaluated an X chromosome dose effect by analyzing 47,XXY (Klinefelter's syndrome, 1 in 500 live male births) among subjects with pSS. 47,XXY was determined by examination of fluorescence intensity of single nucleotide polymorphisms from the X and Y chromosomes. Among 136 pSS men there were 4 with 47,XXY. This was significantly different from healthy controls (1 of 1254 had 47,XXY, p=0.0012 by Fisher's exact test) as well men with rheumatoid arthritis (0 of 363 with 47,XXY), but not different compared to men with systemic lupus erythematosus (SLE) (4 of 136 versus 8 of 306, Fisher's exact test p=NS). These results are consistent with the hypothesis that the number of X chromosomes is critical for the female bias of pSS, a property that may be shared with SLE but not RA.


Assuntos
Artrite Reumatoide/genética , Síndrome de Klinefelter/genética , Lúpus Eritematoso Sistêmico/genética , Síndrome de Sjogren/genética , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único
16.
Immunol Lett ; 173: 21-5, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26973091

RESUMO

In the vast majority of human populations, the gene encoding CASPASE-12 (CASP12) has a premature termination codon that precludes the production of protein. However, approximately 20% of persons of recent African descent have a single nucleotide polymorphism (#rs497116; A->G) that turns the stop codon into one encoding Arg. The subsequent functional allele is a risk factor for sepsis as it uniquely downregulates inflammatory cytokines in African-Americans (AA). To determine if CASP12 could be protective for systemic lupus erythematosus (SLE) in AA, we genotyped AA SLE patients and controls. There was a weak association between CASP12 genotype with the absence of anti-dsDNA autoantibodies in SLE patients. No effect was seen upon serum interleukin-1 beta levels, nor was any other protective effect noted for the CASP12 genotype, whether upon association with SLE, or any of the 11 American College of Rheumatology classification criteria. CASP12 genotype thus does not influence the phenotype of SLE in AA.


Assuntos
Afro-Americanos , Caspase 12/genética , Lúpus Eritematoso Sistêmico/genética , Mutação/genética , Sepse/genética , Adulto , Alelos , Anticorpos Antinucleares/sangue , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Interleucina-1beta/sangue , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
17.
Lupus Sci Med ; 3(1): e000136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27026812

RESUMO

OBJECTIVE: To develop a simple systemic lupus erythematosus (SLE) severity index that requires knowledge of only American College of Rheumatology (ACR) criteria and subcriteria. METHODS: This study used demographic, mortality and medical records data of 1915 patients with lupus from the Lupus Family Registry and Repository. The data were randomly split (2:1 ratio) into independent training and validation sets. A logistic regression with ridge penalty was used to model the probability of being prescribed major immunosuppressive drugs-a surrogate indicator of lupus severity. ACR criteria and subcriteria were used as predictor variables in this model, and the resulting regression coefficient estimates obtained from the training data were used as item weightings to construct the severity index. RESULTS: The resulting index was tested on the independent validation dataset and was found to have high predictive accuracy for immunosuppressive use and early mortality. The index was also found to be strongly correlated with a previously existing severity score for lupus. In addition, demographic factors known to influence lupus severity (eg, age of onset, gender and ethnicity) all showed robust associations with our severity index that were consistent with observed clinical trends. CONCLUSIONS: This new index can be easily computed using ACR criteria, which may be among the most readily available data elements from patient medical records. This tool may be useful in lupus research, especially large dataset analyses to stratify patients by disease severity, an important prognostic indicator in SLE.

18.
Elife ; 52016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26880555

RESUMO

Targeted sequencing of sixteen SLE risk loci among 1349 Caucasian cases and controls produced a comprehensive dataset of the variations causing susceptibility to systemic lupus erythematosus (SLE). Two independent disease association signals in the HLA-D region identified two regulatory regions containing 3562 polymorphisms that modified thirty-seven transcription factor binding sites. These extensive functional variations are a new and potent facet of HLA polymorphism. Variations modifying the consensus binding motifs of IRF4 and CTCF in the XL9 regulatory complex modified the transcription of HLA-DRB1, HLA-DQA1 and HLA-DQB1 in a chromosome-specific manner, resulting in a 2.5-fold increase in the surface expression of HLA-DR and DQ molecules on dendritic cells with SLE risk genotypes, which increases to over 4-fold after stimulation. Similar analyses of fifteen other SLE risk loci identified 1206 functional variants tightly linked with disease-associated SNPs and demonstrated that common disease alleles contain multiple causal variants modulating multiple immune system genes.


Assuntos
Autoimunidade , Regulação da Expressão Gênica , Antígenos HLA-D/biossíntese , Antígenos HLA-D/genética , Polimorfismo Genético , Células Dendríticas/química , Europa (Continente) , Grupo com Ancestrais do Continente Europeu , Humanos , Lúpus Eritematoso Sistêmico/patologia , Proteínas de Membrana/análise , Estados Unidos
19.
Ann Rheum Dis ; 75(11): 2007-2013, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26783109

RESUMO

OBJECTIVES: Following up the systemic lupus erythematosus (SLE) genome-wide association studies (GWAS) identification of NMNAT2 at rs2022013, we fine-mapped its 150 kb flanking regions containing NMNAT2 and SMG7 in a 15 292 case-control multi-ancestry population and tested functions of identified variants. METHODS: We performed genotyping using custom array, imputation by IMPUTE 2.1.2 and allele specific functions using quantitative real-time PCR and luciferase reporter transfections. SLE peripheral blood mononuclear cells (PBMCs) were cultured with small interfering RNAs to measure antinuclear antibody (ANA) and cyto/chemokine levels in supernatants using ELISA. RESULTS: We confirmed association at NMNAT2 in European American (EA) and Amerindian/Hispanic ancestries, and identified independent signal at SMG7 tagged by rs2702178 in EA only (p=2.4×10-8, OR=1.23 (95% CI 1.14 to 1.32)). In complete linkage disequilibrium with rs2702178, rs2275675 in the promoter region robustly associated with SMG7 mRNA levels in multiple expression quantitative trait locus (eQTL) datasets. Its risk allele was dose-dependently associated with decreased SMG7 mRNA levels in PBMCs of 86 patients with SLE and 119 controls (p=1.1×10-3 and 6.8×10-8, respectively) and conferred reduced transcription activity in transfected HEK-293 (human embryonic kidney cell line) and Raji cells (p=0.0035 and 0.0037, respectively). As a critical component in the nonsense-mediated mRNA decay pathway, SMG7 could regulate autoantigens including ribonucleoprotein (RNP) and Smith (Sm). We showed SMG7 mRNA levels in PBMCs correlated inversely with ANA titres of patients with SLE (r=-0.31, p=0.01), and SMG7 knockdown increased levels of ANA IgG and chemokine (C-C motif) ligand 19 in SLE PBMCs (p=2.0×10-5 and 2.0×10-4, respectively). CONCLUSION: We confirmed NMNAT2 and identified independent SMG7 association with SLE. The inverse relationship between levels of the risk allele-associated SMG7 mRNAs and ANA suggested the novel contribution of mRNA surveillance pathway to SLE pathogenesis.


Assuntos
Anticorpos Antinucleares/metabolismo , Proteínas de Transporte/genética , Leucócitos Mononucleares/imunologia , Lúpus Eritematoso Sistêmico/genética , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Alelos , Grupo com Ancestrais Nativos do Continente Americano/genética , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Células HEK293 , Hispano-Americanos/genética , Humanos , Desequilíbrio de Ligação , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Linhagem , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco
20.
Arthritis Rheumatol ; 68(4): 932-43, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26606652

RESUMO

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a strong genetic component. We undertook the present work to perform the first genome-wide association study on individuals from the Americas who are enriched for Native American heritage. METHODS: We analyzed 3,710 individuals from the US and 4 countries of Latin America who were diagnosed as having SLE, and healthy controls. Samples were genotyped with HumanOmni1 BeadChip. Data on out-of-study controls genotyped with HumanOmni2.5 were also included. Statistical analyses were performed using SNPtest and SNPGWA. Data were adjusted for genomic control and false discovery rate. Imputation was performed using Impute2 and, for classic HLA alleles, HiBag. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: The IRF5-TNPO3 region showed the strongest association and largest OR for SLE (rs10488631: genomic control-adjusted P [Pgcadj ] = 2.61 × 10(-29), OR 2.12 [95% CI 1.88-2.39]), followed by HLA class II on the DQA2-DQB1 loci (rs9275572: Pgcadj = 1.11 × 10(-16), OR 1.62 [95% CI 1.46-1.80] and rs9271366: Pgcadj = 6.46 × 10(-12), OR 2.06 [95% CI 1.71-2.50]). Other known SLE loci found to be associated in this population were ITGAM, STAT4, TNIP1, NCF2, and IRAK1. We identified a novel locus on 10q24.33 (rs4917385: Pgcadj = 1.39 × 10(-8)) with an expression quantitative trait locus (eQTL) effect (Peqtl = 8.0 × 10(-37) at USMG5/miR1307), and several new suggestive loci. SLE risk loci previously identified in Europeans and Asians were corroborated. Local ancestry estimation showed that the HLA allele risk contribution is of European ancestral origin. Imputation of HLA alleles suggested that autochthonous Native American haplotypes provide protection against development of SLE. CONCLUSION: Our results demonstrate that studying admixed populations provides new insights in the delineation of the genetic architecture that underlies autoimmune and complex diseases.


Assuntos
Grupo com Ancestrais Nativos do Continente Americano/genética , Lúpus Eritematoso Sistêmico/genética , Argentina , Antígeno CD11b/genética , Estudos de Casos e Controles , Chile , Cromossomos Humanos Par 10/genética , Proteínas de Ligação a DNA/genética , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Antígenos HLA-DQ/genética , Cadeias beta de HLA-DQ/genética , Haplótipos , Humanos , Fatores Reguladores de Interferon , Quinases Associadas a Receptores de Interleucina-1/genética , Masculino , México , ATPases Mitocondriais Próton-Translocadoras/genética , NADPH Oxidases/genética , Razão de Chances , Peru , Análise de Componente Principal , Fator de Transcrição STAT4/genética , Estados Unidos , beta Carioferinas
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