RESUMO
OBJECTIVES: There is an unmet need for novel blood-based biomarkers that offer timely and accurate diagnostic and prognostic testing in inflammatory bowel diseases (IBD). We aimed to investigate the diagnostic and prognostic utility of serum calprotectin (SC) in IBD. METHODS: A total of 171 patients (n=96 IBD, n=75 non-IBD) were prospectively recruited. A multi-biomarker model was derived using multivariable logistic regression analysis. Cox proportional hazards model was derived to assess the contribution of each variable to disease outcomes. RESULTS: SC correlated strongly with current biomarkers, including fecal calprotectin (FC) (n=50, ρ=0.50, P=1.6 × 10-4). SC was the strongest individual predictor of IBD diagnosis (odds ratio (OR): 9.37 (95% confidence interval (CI): 2.82-34.68), P=4.00 × 10-4) compared with other markers (C-reactive protein (CRP): OR 8.52 (95% CI: 2.75-28.63), P=2.80 × 10-4); albumin: OR 6.12 (95% CI: 1.82-22.16), P=0.004). In a subset of 50 patients with paired SC and FC, the area under receiver operating characteristic discriminating IBD from controls was better for FC than for SC (0.99, (95% CI 0.87-1.00) and 0.87 (95% CI:0.78-0.97), respectively; P=0.01). At follow-up (median 342 days; interquartile range: 88-563), SC predicted treatment escalation and/or surgery in IBD (hazard ratio (HR) 2.7, 95% CI: 1.1-4.9), in particular Crohn's disease (CD) (HR 4.2, 95% CI 1.2-15.3). A model incorporating SC and either CRP or albumin has a positive likelihood ratio of 24.14 for IBD. At 1 year, our prognostic model can predict treatment escalation in IBD in 65% of cases (95% CI: 43-79%) and 80% (95% CI: 31-94%) in CD if ≥2 blood marker criteria are met. CONCLUSIONS: A diagnostic and prognostic model that combines SC and other blood-based biomarkers accurately predicts the inflammatory burden in IBD and has the potential to predict disease and its outcomes. Our data warrant further detailed exploration and validation in large multicenter cohorts.
Assuntos
Colite Ulcerativa/sangue , Doença de Crohn/sangue , Complexo Antígeno L1 Leucocitário/sangue , Adulto , Área Sob a Curva , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/fisiopatologia , Doença de Crohn/diagnóstico , Doença de Crohn/fisiopatologia , Progressão da Doença , Feminino , Humanos , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/fisiopatologia , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Sensibilidade e Especificidade , Albumina Sérica/metabolismo , Adulto JovemRESUMO
A genome-wide association scan in individuals with Crohn's disease by the Wellcome Trust Case Control Consortium detected strong association at four novel loci. We tested 37 SNPs from these and other loci for association in an independent case-control sample. We obtained replication for the autophagy-inducing IRGM gene on chromosome 5q33.1 (replication P = 6.6 x 10(-4), combined P = 2.1 x 10(-10)) and for nine other loci, including NKX2-3, PTPN2 and gene deserts on chromosomes 1q and 5p13.
Assuntos
Autofagia/genética , Doença de Crohn/genética , Proteínas de Ligação ao GTP/genética , Predisposição Genética para Doença , Variação Genética , Animais , Estudos de Casos e Controles , Humanos , Camundongos , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
In the past decade, there have been fundamental advances in our understanding of genetic factors that contribute to the inflammatory bowel diseases (IBDs) Crohn's disease and ulcerative colitis. The latest international collaborative studies have brought the number of IBD susceptibility gene loci to 163. However, genetic factors account for only a portion of overall disease variance, indicating a need to better explore gene-environment interactions in the development of IBD. Epigenetic factors can mediate interactions between the environment and the genome; their study could provide new insight into the pathogenesis of IBD. We review recent progress in identification of genetic factors associated with IBD and discuss epigenetic mechanisms that could affect development and progression of IBD.
Assuntos
Colite Ulcerativa/genética , Doença de Crohn/genética , Epigênese Genética , Epigenômica , Predisposição Genética para Doença , HumanosRESUMO
OBJECTIVE: Mutations in the nucleotide-binding oligomerisation domain-containing protein 2 (NOD2) gene remain the strongest genetic determinants for Crohn's disease (CD). Having previously identified vimentin as a novel NOD2-interacting protein, the authors aimed to investigate the regulatory effects of vimentin on NOD2 function and the association of variants in Vim with CD susceptibility. DESIGN: Coimmunoprecipitation, fluorescent microscopy and fractionation were used to confirm the interaction between NOD2 and vimentin. HEK293 cells stably expressing wild-type NOD2 or a NOD2 frameshift variant (L1007fs) and SW480 colonic epithelial cells were used alongside the vimentin inhibitor, withaferin A (WFA), to assess effects on NOD2 function using the nuclear factor-kappaB (NF-κB) reporter gene, green fluorescent protein-LC3-based autophagy, and bacterial gentamicin protection assays. International genome-wide association meta-analysis data were used to test for associations of single-nucleotide polymorphisms in Vim with CD susceptibility. RESULTS: The leucine-rich repeat domain of NOD2 contained the elements required for vimentin binding; CD-associated polymorphisms disrupted this interaction. NOD2 and vimentin colocalised at the cell plasma membrane, and cytosolic mislocalisation of the L1007fs and R702W variants correlated with an inability to interact with vimentin. Use of WFA demonstrated that vimentin was required for NOD2-dependent NF-κB activation and muramyl dipeptide-induced autophagy induction, and that NOD2 and vimentin regulated the invasion and survival properties of a CD-associated adherent-invasive Escherichia coli strain. Genetic analysis revealed an association signal across the haplotype block containing Vim. CONCLUSION: Vimentin is an important regulator of NOD2 function and a potential novel therapeutic target in the treatment of CD. In addition, Vim is a candidate susceptibility gene for CD, supporting the functional data.
Assuntos
Doença de Crohn/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Vimentina/metabolismo , Colo/metabolismo , Colo/patologia , Doença de Crohn/genética , Doença de Crohn/patologia , Doença de Crohn/fisiopatologia , Suscetibilidade a Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Mutação da Fase de Leitura , Células HEK293 , Humanos , Imunoprecipitação , Microscopia de Fluorescência , Proteína Adaptadora de Sinalização NOD2/genética , Polimorfismo de Nucleotídeo Único , Vimentina/genética , Vitanolídeos/farmacologiaRESUMO
BACKGROUND & AIMS: The mechanisms by which specific mutations in NOD2/CARD15 increase the risk for Crohn's disease (CD) are unclear. We identified proteins that interact with NOD2 and investigated them by expression, genetic, and functional analyses. METHODS: By using a yeast 2-hybrid screen of an intestinal epithelial library, we identified proteins that interact with NOD2 and confirmed the interactions in mammalian cells using co-immunoprecipitation. We used microarray analysis to analyze gene expression patterns in 302 intestinal biopsy samples (129 from patients with ulcerative colitis [UC], 106 with CD, and 67 controls). Eighty single-nucleotide polymorphisms within the genes that encoded 6 interacting proteins were genotyped in a discovery cohort (869 cases of inflammatory bowel disease [IBD], 885 controls) and a replication cohort (504 patients with IBD, 713 controls). We investigated interaction between transducin-like enhancer of split 1 (TLE1) and NOD2 in HEK293 cells. RESULTS: We identified 6 NOD2-interacting proteins (TLE1, UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 2 [GALNT2], HIV-1 Tat interactive protein [HTATIP], Vimentin, fission 1 (mitochondrial outer membrane) homolog [FIS1], and protein phosphatase 2, regulatory subunit B', epsilon isoform [PPP2R5E]). Of these, expression of GALNT2 (CD, P = .004) and vimentin (CD, P = .006; UC, P = .0025) was altered in patients with IBD compared with controls. Single-nucleotide polymorphisms within TLE1 were associated with susceptibility to CD, specifically with ileal disease (rs6559629, P = 3.1 × 10â»5; odds ratio, 1.45). The TLE1 risk allele is required for susceptibility to CD in carriers of NOD2 mutations. In cells, TLE1 and NOD2 co-localized around the nuclear membrane and TLE1 inhibited activation of nuclear factor-κB by NOD2. CONCLUSIONS: Epistatic and biological interactions between TLE1 and NOD2 are involved in IBD pathogenesis. NOD2 might be involved in a series of pathways such as epigenetic regulation of expression (via TLE1 and HTATIP), biosynthesis of mucin (via GALNT2), apoptosis (via PPP2R5E and FIS1), and integrity of the intracellular cytoskeleton (vimentin).
Assuntos
Doença de Crohn/genética , Doença de Crohn/fisiopatologia , Epistasia Genética/fisiologia , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/fisiologia , Proteínas Repressoras/genética , Proteínas Repressoras/fisiologia , Biópsia , Estudos de Casos e Controles , Proteínas Correpressoras , Colite Ulcerativa/genética , Colite Ulcerativa/patologia , Colite Ulcerativa/fisiopatologia , Colo/metabolismo , Colo/patologia , Doença de Crohn/patologia , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Lisina Acetiltransferase 5 , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Análise em Microsséries , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Mutação/genética , N-Acetilgalactosaminiltransferases/genética , N-Acetilgalactosaminiltransferases/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Transdução de Sinais/fisiologia , Vimentina/genética , Vimentina/metabolismo , Polipeptídeo N-AcetilgalactosaminiltransferaseRESUMO
BACKGROUND & AIMS: Identifying shared and disease-specific susceptibility loci for Crohn's disease (CD) and ulcerative colitis (UC) would help define the biologic relationship between the inflammatory bowel diseases. More than 30 CD susceptibility loci have been identified. These represent important candidate susceptibility loci for UC. Loci discovered by the index genome scans in CD have previously been tested for association with UC, but those identified in the recent meta-analysis await such investigation. Furthermore, the recently identified UC locus at ECM1 requires formal testing for association with CD. METHODS: We analyzed 45 single nucleotide polymorphisms, tagging 29 of the loci recently associated with CD in 2527 UC cases and 4070 population controls. We also genotyped the UC-associated ECM1 variant rs11205387 in 1560 CD patients and 3028 controls. RESULTS: Nine regions showed association with UC at a threshold corrected for the 29 loci tested (P < .0017). The strongest association (P = 4.13 x 10(-8); odds ratio = 1.27) was identified with a 170-kilobase region on chromosome 1q32 that contains 3 genes. We also found association with JAK2 and replicated a recently reported association with STAT3, further implicating the role of this signaling pathway in inflammatory bowel disease. Additional novel UC susceptibility genes were LYRM4 and CDKAL1. Twenty of the loci were not associated with UC, and several appear to be specific to CD. ECM1 variation was not associated with CD. CONCLUSIONS: Collectively, these data help define the genetic relationship between CD and UC and characterize common, as well as disease-specific mechanisms of pathogenesis.
Assuntos
Colite Ulcerativa/genética , Doença de Crohn/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Estudos de Casos e Controles , Quinase 5 Dependente de Ciclina/genética , Proteínas da Matriz Extracelular/genética , Feminino , Genótipo , Humanos , Janus Quinase 2/genética , Masculino , Fatores de Risco , Fator de Transcrição STAT3/genética , tRNA MetiltransferasesRESUMO
BACKGROUND & AIMS: Childhood-onset inflammatory bowel disease (IBD) might be etiologically different from adult-onset IBD. We analyzed disease phenotypes and progression of childhood-onset disease and compared them with characteristics of adult-onset disease in patients in Scotland. METHODS: Anatomic locations and behaviors were assessed in 416 patients with childhood-onset (276 Crohn's disease [CD], 99 ulcerative colitis [UC], 41 IBD type unclassified [IBDU] diagnosed before seventeenth birthday) and 1297 patients with adult-onset (596 CD, 701 UC) IBD using the Montreal classification. RESULTS: At the time of diagnosis in children, CD involved small bowel and colon (L3) in 51% (138/273), colon (L2) in 36%, and ileum (L1) in 6%; the upper gastrointestinal (GI) tract (L4) was also affected in 51%. In 39%, the anatomic extent increased within 2 years. Behavioral characteristics progressed; 24% of children developed stricturing or penetrating complications within 4 years (vs 9% at diagnosis; P < .0001; odds ratio [OR], 3.32; 95% confidence interval [CI], 1.86-5.92). Compared with adults, childhood-onset disease was characterized by a "panenteric" phenotype (ileocolonic plus upper GI [L3+L4]; 43% vs 3%; P < .0001; OR, 23.36; 95% CI, 13.45-40.59) with less isolated ileal (L1; 2% vs 31%; P < .0001; OR, 0.06; 95% CI, 0.03-0.12) or colonic disease (L2; 15% vs 36%; P < .0001; OR, 0.31; 95% CI, 0.21-0.46). UC was extensive in 82% of the children at diagnosis, versus 48% of adults (P < .0001; OR, 5.08; 95% CI, 2.73-9.45); 46% of the children progressed to develop extensive colitis during follow-up. Forty-six percent of children with CD and 35% with UC required immunomodulatory therapy within 12 months of diagnosis. The median time to first surgery was longer in childhood-onset than adult-onset patients with CD (13.7 vs 7.8 years; P < .001); the reverse was true for UC. CONCLUSIONS: Childhood-onset IBD is characterized by extensive intestinal involvement and rapid early progression.
Assuntos
Colite Ulcerativa/classificação , Colite Ulcerativa/diagnóstico , Doença de Crohn/classificação , Doença de Crohn/diagnóstico , Adolescente , Adulto , Idade de Início , Criança , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/terapia , Doença de Crohn/epidemiologia , Doença de Crohn/terapia , Procedimentos Cirúrgicos do Sistema Digestório/estatística & dados numéricos , Progressão da Doença , Feminino , Seguimentos , Humanos , Fatores Imunológicos/uso terapêutico , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Fenótipo , Prevalência , Escócia/epidemiologiaRESUMO
BACKGROUND: Ulcerative colitis (UC) and Crohn's disease (CD) are polygenic chronic inflammatory bowel diseases (IBD) of high prevalence that are associated with considerable morbidity. The hedgehog (HH) signalling pathway, which includes the transcription factor glioma-associated oncogene homolog 1 (GLI1), plays vital roles in gastrointestinal tract development, homeostasis, and malignancy. We identified a germline variation in GLI1 (within the IBD2 linkage region, 12q13) in patients with IBD. Since this IBD-associated variant encodes a GLI1 protein with reduced function and our expression studies demonstrated down-regulation of the HH response in IBD, we tested whether mice with reduced Gli1 activity demonstrate increased susceptibility to chemically induced colitis. METHODS AND FINDINGS: Using a gene-wide haplotype-tagging approach, germline GLI1 variation was examined in three independent populations of IBD patients and healthy controls from Northern Europe (Scotland, England, and Sweden) totalling over 5,000 individuals. On log-likelihood analysis, GLI1 was associated with IBD, predominantly UC, in Scotland and England (p < 0.0001). A nonsynonymous SNP (rs2228226C-->G), in exon 12 of GLI1 (Q1100E) was strongly implicated, with pooled odds ratio of 1.194 (confidence interval = 1.09-1.31, p = 0.0002). GLI1 variants were tested in vitro for transcriptional activity in luciferase assays. Q1100E falls within a conserved motif near the C terminus of GLI1; the variant GLI protein exhibited reduced transactivation function in vitro. In complementary expression studies, we noted the colonic HH response, including GLI1, patched (PTCH), and hedgehog-interacting protein (HHIP), to be down-regulated in patients with UC. Finally, Gli1(+/lacZ) mice were tested for susceptibility to dextran sodium sulphate (DSS)-induced colitis. Clinical response, histology, and expression of inflammatory cytokines and chemokines were recorded. Gli1(+/lacZ) mice rapidly developed severe intestinal inflammation, with considerable morbidity and mortality compared with wild type. Local myeloid cells were shown to be direct targets of HH signals and cytokine expression studies revealed robust up-regulation of IL-12, IL-17, and IL-23 in this model. CONCLUSIONS: HH signalling through GLI1 is required for appropriate modulation of the intestinal response to acute inflammatory challenge. Reduced GLI1 function predisposes to a heightened myeloid response to inflammatory stimuli, potentially leading to IBD.
Assuntos
Mutação em Linhagem Germinativa , Proteínas Hedgehog/fisiologia , Doenças Inflamatórias Intestinais/genética , Polimorfismo de Nucleotídeo Único , Transdução de Sinais/genética , Fatores de Transcrição/genética , Adulto , Animais , Inglaterra , Feminino , Perfilação da Expressão Gênica , Predisposição Genética para Doença , Testes Genéticos , Proteínas Hedgehog/genética , Humanos , Inflamação/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Escócia , Transdução de Sinais/imunologia , Suécia , Proteína GLI1 em Dedos de ZincoRESUMO
Progress in the genetics of complex diseases has been slow over the past two decades compared to many simple Mendelian traits. However, rapid advances are now being made in inflammatory bowel disease genetics, leading already to identification of the first gene linked to Crohn's disease susceptibility: NOD2/CARD15. Since its discovery three years ago, there has been replication of the association of NOD2/CARD15 mutations with Crohn's disease in many populations, together with identification of phenotypic correlations. Functional studies promise to increase understanding of the primary pathophysiology involved in Crohn's disease and these discoveries may yet change clinical practice.
Assuntos
Doença de Crohn/genética , Ligação Genética/genética , Predisposição Genética para Doença/genética , Genética Populacional , Peptídeos e Proteínas de Sinalização Intracelular/genética , Animais , Mapeamento Cromossômico , Modelos Animais de Doenças , Frequência do Gene , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Camundongos , Biologia Molecular , Proteína Adaptadora de Sinalização NOD2RESUMO
The chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis are common causes of gastrointestinal disease in northern Europe, affecting as many as one in 250 people. Although mortality is low, morbidity associated with these diseases is substantial. We review the recent advances in the genetics of inflammatory bowel disease, with particular emphasis on the data that have been generated since the discovery of the CARD15 (NOD2) gene in 2001.
Assuntos
Doenças Inflamatórias Intestinais/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Animais , Colite Ulcerativa/genética , Doença de Crohn/genética , Europa (Continente)/epidemiologia , Predisposição Genética para Doença , Genética Populacional , Humanos , Doenças Inflamatórias Intestinais/epidemiologia , Fenótipo , Receptor 4 Toll-Like/genéticaRESUMO
The discovery of nucleotide-binding oligomerization domain 2/caspase recruitment domain-containing protein 15 (NOD2/CARD15) as the first susceptibility gene in Crohn's disease (CD) has shifted the focus of research into the pathogenesis of inflammatory bowel disease (IBD) firmly to the innate immune response and the integrity of the epithelial barrier. The subsequent implication in IBD of variant alleles of OCTN, DLG5, MDR1, and TLRs has provided further support for a new, more complex model of innate immunity function in the gastrointestinal tract. In this review, we examine the recent advances in our understanding of the influence of genetics of the innate immune response on IBD. We will focus on germline variation of genes encoding pathogen-recognition receptors, proteins involved in epithelial homeostasis and secreted antimicrobial proteins.
Assuntos
Predisposição Genética para Doença , Imunidade Inata/genética , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , HumanosRESUMO
BACKGROUND: Inflammatory bowel disease (IBD) is an epithelial barrier disease that is thought to result from a dysregulated interaction with bacteria in the intestine of genetically predisposed individuals. The cystic fibrosis transmembrane conductance regulator (CFTR), which is mutated in the autosomal recessive disease cystic fibrosis, modulates gut permeability, mucus production, and epithelial interactions with bacteria. The cystic fibrosis DeltaF508 mutation is commonly found in the general population and has been shown to result in a reduced number of CFTR molecules at the surface of epithelial cells. Given the important biological functions of CFTR in the intestine, we tested whether this mutation is of relevance to IBD. METHODS: Using DNA heteroduplex analysis, we investigated the distribution of DeltaF508 heterozygosity in 2568 subjects from three independent cohorts of Italian, Swedish, and Scottish IBD patients and controls. RESULTS: In all three cohorts an association between DeltaF508 and Crohn's disease (CD) was observed. Specifically, DeltaF508 heterozygosity was markedly underrepresented in CD patients from Italy and Sweden (P = 0.021 and 0.027 versus controls, respectively), while stratification for disease location revealed an absence of DeltaF508 carriers among Scottish CD patients with right-sided colitis (P = 0.023 versus all other locations). CONCLUSIONS: DeltaF508 heterozygosity might exert a protective effect in CD.
Assuntos
Doença de Crohn/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Mutação , Adolescente , Adulto , Doença de Crohn/patologia , Doença de Crohn/fisiopatologia , Regulador de Condutância Transmembrana em Fibrose Cística/fisiologia , Feminino , Triagem de Portadores Genéticos , Predisposição Genética para Doença , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fenótipo , Escócia , SuéciaRESUMO
Genetic association studies have identified 215 risk loci for inflammatory bowel disease, thereby uncovering fundamental aspects of its molecular biology. We performed a genome-wide association study of 25,305 individuals and conducted a meta-analysis with published summary statistics, yielding a total sample size of 59,957 subjects. We identified 25 new susceptibility loci, 3 of which contain integrin genes that encode proteins in pathways that have been identified as important therapeutic targets in inflammatory bowel disease. The associated variants are correlated with expression changes in response to immune stimulus at two of these genes (ITGA4 and ITGB8) and at previously implicated loci (ITGAL and ICAM1). In all four cases, the expression-increasing allele also increases disease risk. We also identified likely causal missense variants in a gene implicated in primary immune deficiency, PLCG2, and a negative regulator of inflammation, SLAMF8. Our results demonstrate that new associations at common variants continue to identify genes relevant to therapeutic target identification and prioritization.
Assuntos
Predisposição Genética para Doença/genética , Doenças Inflamatórias Intestinais/genética , Integrinas/genética , Alelos , Estudo de Associação Genômica Ampla/métodos , Humanos , Inflamação/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genéticaRESUMO
The inflammatory bowel disease, Crohn's disease and ulcerative colitis, are polygenic disorders with important environmental interactions. To date, the most widely adopted approach to identifying susceptibility genes in complex diseases has involved genome wide linkage studies followed by studies of positional candidate genes in loci of interest. This review encompasses data from studies into novel candidate genes implicated in the pathogenesis of inflammatory bowel disease. Novel techniques to identify candidate genes-genome wide association studies, yeast-two hybrid screening, microarray gene expression studies and proteomic profiling, are also reviewed and their potential role in unravelling the pathogenesis of inflammatory bowel disease are discussed.
Assuntos
Predisposição Genética para Doença , Doenças Inflamatórias Intestinais/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Quimiocina CCL20 , Quimiocinas CC/genética , Genoma Humano , Humanos , Imunidade Inata/genética , Proteínas Inflamatórias de Macrófagos/genética , Proteína Adaptadora de Sinalização NOD1 , Análise de Sequência com Séries de Oligonucleotídeos , Proteômica , Receptor 4 Toll-Like/genética , Receptor 5 Toll-Like/genética , Técnicas do Sistema de Duplo-HíbridoRESUMO
Previous work has shown that the gene DMBT1, which encodes a large secreted epithelial glycoprotein known as salivary agglutinin, gp340, hensin or muclin, is an innate immune defence protein that binds bacteria. A deletion variant of DMBT1 has been previously associated with Crohn's disease, and a DMBT1(-/-) knockout mouse has increased levels of colitis induced by dextran sulphate. DMBT1 has a complex copy number variable structure, with two, independent, rapidly mutating copy number variable regions, called CNV1 and CNV2. Because the copy number variable regions are predicted to affect the number of bacteria-binding domains, different alleles may alter host-microbe interactions in the gut. Our aim was to investigate the role of this complex variation in susceptibility to Crohn's disease by assessing the previously reported association. We analysed the association of both copy number variable regions with presence of Crohn's disease, and its severity, on three case-control cohorts. We also reanalysed array comparative genomic hybridisation data (aCGH) from a large case-control cohort study for both copy number variable regions. We found no association with a linear increase in copy number, nor when the CNV1 is regarded as presence or absence of a deletion allele. Taken together, we show that the DMBT1 CNV does not affect susceptibility to Crohn's disease, at least in Northern Europeans.
Assuntos
Doença de Crohn/genética , Variações do Número de Cópias de DNA , Receptores de Superfície Celular/genética , Alelos , Proteínas de Ligação ao Cálcio , Estudos de Casos e Controles , Cisteína/química , Proteínas de Ligação a DNA , Humanos , Domínios Proteicos , Receptores de Superfície Celular/química , Proteínas Supressoras de TumorRESUMO
INTRODUCTION: The incidence of early-onset CD in Scotland is among the highest worldwide. Three single nucleotide polymorphisms (SNPs) R702W, G908R and Leu1007finsC in the NOD2/CARD15 gene predispose to adult CD. We investigated the contribution of these variants to disease susceptibility and phenotype in the Scottish early-onset IBD population. PATIENTS AND METHODS: 906 individuals including 247 Scottish IBD patients aged <16 years at diagnosis, 414 parents and 245 controls were genotyped. Transmission disequilibrium testing (TDT), case-control analysis and detailed genotype-phenotype analysis were performed. RESULTS: The Leu1007finsC variant was associated with susceptibility to CD by case-control (4.2% versus. 1.4%, P = 0.01) and TDT analysis (P = 0.006). The Population Attributable Risk (PAR) for the 3 NOD2/CARD15 mutations was 7.9%. Carriage of NOD2/CARD15 variants was associated with, at diagnosis: decreased albumin (31.0% versus. 9.0%, P = 0.001) and raised CRP (25% versus. 9.5%, P = 0.04) and at follow up: need for surgery (39.5% versus. 12.8%, P = 0.0002) jejunal involvement (50% versus. 18.4%, P = 0.01) jejunal and ileal involvement (50% versus. 10.7%, P = 0.009), raised CRP (57.1% and 12.8%, P = 0.0009), lower weight/height centile (75.0% versus. 20.2%, P = 0.03, 50.0% versus. 16.0%, P = 0.001 respectively) and stricturing disease (45.5% versus. 19.4%, P < 0.05). Multifactorial analysis demonstrated carriage was associated with need for surgery (P = 0.004, OR 4.9 [1.5-14.7]). CONCLUSIONS: These NOD2/CARD 15 variants in the Scottish early onset CD population have a definite, albeit relatively small contribution to CD susceptibility (PAR 7.9%) but a major impact on phenotype. In particular NOD2/CARD15 variants are strongly associated with several markers of disease severity in pediatric CD, notably need for surgery.
Assuntos
Doença de Crohn/genética , Doença de Crohn/patologia , Predisposição Genética para Doença , Peptídeos e Proteínas de Sinalização Intracelular/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Idade de Início , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Proteína Adaptadora de Sinalização NOD2 , Fenótipo , Fatores de Risco , Escócia , Índice de Gravidade de DoençaRESUMO
INTRODUCTION: Serum N-glycans have been identified as putative biomarkers for numerous diseases. The impact of different serum sample tubes and processing methods on N-glycan analysis has received relatively little attention. This study aimed to determine the effect of different sample tubes and processing methods on the whole serum N-glycan profile in both health and disease. A secondary objective was to describe a robot automated N-glycan release, labeling and cleanup process for use in a biomarker discovery system. METHODS: 25 patients with active and quiescent inflammatory bowel disease and controls had three different serum sample tubes taken at the same draw. Two different processing methods were used for three types of tube (with and without gel-separation medium). Samples were randomised and processed in a blinded fashion. Whole serum N-glycan release, 2-aminobenzamide labeling and cleanup was automated using a Hamilton Microlab STARlet Liquid Handling robot. Samples were analysed using a hydrophilic interaction liquid chromatography/ethylene bridged hybrid(BEH) column on an ultra-high performance liquid chromatography instrument. Data were analysed quantitatively by pairwise correlation and hierarchical clustering using the area under each chromatogram peak. Qualitatively, a blinded assessor attempted to match chromatograms to each individual. RESULTS: There was small intra-individual variation in serum N-glycan profiles from samples collected using different sample processing methods. Intra-individual correlation coefficients were between 0.99 and 1. Unsupervised hierarchical clustering and principal coordinate analyses accurately matched samples from the same individual. Qualitative analysis demonstrated good chromatogram overlay and a blinded assessor was able to accurately match individuals based on chromatogram profile, regardless of disease status. CONCLUSIONS: The three different serum sample tubes processed using the described methods cause minimal inter-individual variation in serum whole N-glycan profile when processed using an automated workstream. This has important implications for N-glycan biomarker discovery studies using different serum processing standard operating procedures.
Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Glicoproteínas/sangue , Polissacarídeos/sangue , Adulto , Biomarcadores/sangue , Análise Química do Sangue , Proteínas Sanguíneas/isolamento & purificação , Proteínas Sanguíneas/metabolismo , Cromatografia Líquida de Alta Pressão , Feminino , Glicoproteínas/isolamento & purificação , Humanos , Doenças Inflamatórias Intestinais/sangue , Masculino , Pessoa de Meia-Idade , Polissacarídeos/isolamento & purificaçãoRESUMO
BACKGROUND: Glycobiology is an underexplored research area in inflammatory bowel disease (IBD), and glycans are relevant to many etiological mechanisms described in IBD. Alterations in N-glycans attached to the immunoglobulin G (IgG) Fc fragment can affect molecular structure and immunological function. Recent genome-wide association studies reveal pleiotropy between IBD and IgG glycosylation. This study aims to explore IgG glycan changes in ulcerative colitis (UC) and Crohn's disease (CD). METHODS: IgG glycome composition in patients with UC (n = 507), CD (n = 287), and controls (n = 320) was analyzed by ultra performance liquid chromatography. RESULTS: Statistically significant differences in IgG glycome composition between patients with UC or CD, compared with controls, were observed. Both UC and CD were associated with significantly decreased IgG galactosylation (digalactosylation, UC: odds ratio [OR] = 0.71; 95% confidence interval [CI], 0.5-0.9; P = 0.01; CD: OR = 0.41; CI, 0.3-0.6; P = 1.4 × 10) and significant decrease in the proportion of sialylated structures in CD (OR = 0.46, CI, 0.3-0.6, P = 8.4 × 10). Logistic regression models incorporating measured IgG glycan traits were able to distinguish UC and CD from controls (UC: P = 2.13 × 10 and CD: P = 2.20 × 10), with receiver-operator characteristic curves demonstrating better performance of the CD model (area under curve [AUC] = 0.77) over the UC model (AUC = 0.72) (P = 0.026). The ratio of the presence to absence of bisecting GlcNAc in monogalactosylated structures was increased in patients with UC undergoing colectomy compared with no colectomy (FDR-adjusted, P = 0.05). CONCLUSIONS: The observed differences indicate significantly increased inflammatory potential of IgG in IBD. Changes in IgG glycosylation may contribute to IBD pathogenesis and could alter monoclonal antibody therapeutic efficacy. IgG glycan profiles have translational potential as IBD biomarkers.
Assuntos
Imunoglobulina G/imunologia , Doenças Inflamatórias Intestinais/imunologia , Polissacarídeos/imunologia , Adulto , Estudos de Casos e Controles , Cromatografia Líquida , Feminino , Glicosilação , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/genética , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/genética , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polissacarídeos/genética , Polissacarídeos/metabolismo , Curva ROCRESUMO
BACKGROUND: Crohn's disease (CD) is characterized by heterogeneity of phenotype. The Vienna classification can be used to classify CD, and recent data illustrate that behavior evolves over the course of the disease. Clinical and biological influences on disease progression remain unclear. We examined the associations of CD disease progression at diagnosis and for up to 20 years of follow-up. METHODS: Two hundred thirty-one well-characterized CD patients were studied. Demographic, clinical, and NOD2/CARD15 data were collected. Disease behavior according to the Vienna classification was assessed at diagnosis and for up to 20 years following diagnosis. RESULTS: At diagnosis, 70% of patients had inflammatory disease, 9% stricturing, and 21% penetrating. Early age at diagnosis was associated with ileocolonic and upper GI disease (p = 0.015), and positive anti-Saccharomyces cerevisiae antibody (ASCA) was associated with ileal involvement (p = 0.008). Smoking was relatively protective against colonic, rather than ileal involvement at diagnosis (p < 0.02). At 20 years, 92% had progressed to a more severe disease type. Patients who progress to a more severe disease type require more frequent surgery (p < 0.00001). Multivariate analysis found disease progression to be associated with ileal disease location (p = 0.001) and positive ASCA (p = 0.003). Variant NOD2/CARD15 alleles were protective against rapid progression of disease phenotype (p = 0.04). The presence of perianal disease was independent of intestinal penetrating disease. CONCLUSIONS: The progression of disease type in CD is associated with the need for more frequent surgery. Rapid progression is associated with ileal disease and positive ASCA, and delayed progression is associated with variant NOD2/CARD15 alleles. Consideration should be given to a separate Vienna classification for perianal disease.