| 1. |
- Soderman, Jan, et al.
(författare)
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Analysis of single nucleotide polymorphisms in the region of CLDN2-MORC4 in relation to inflammatory bowel disease
- 2013
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Inc.. - 1007-9327 .- 2219-2840. ; 19:30, s. 4935-4943
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate a possible genetic influence of claudin (CLDN) 1, CLDN2 and CLDN4 in the etiology of inflammatory bowel disease.METHODS: Allelic association between genetic regions of CLDN1, CLDN2 or CLDN4 and patients with inflammatory bowel disease, Crohn's disease (CD) or ulcerative colitis were investigated using both a case-control study approach (one case randomly selected from each of 191 Swedish inflammatory bowel disease families and 333 controls) and a family-based study (463 non-Swedish European inflammatory bowel disease-families). A nonsynonymous coding single nucleotide polymorphism in MORC4, located on the same linkage block as CLDN2, was investigated for association, as were two novel CLDN2 single nucleotide polymorphism markers, identified by resequencing.RESULTS: A single nucleotide polymorphism marker (rs12014762) located in the genetic region of CLDN2 was significantly associated to CD (case-control allelic OR = 1.98, 95% CI: 1.17-3.35, P = 0.007). MORC4 was present on the same linkage block as this CD marker. Using the case-control approach, a significant association (case control allelic OR = 1.61, 95% CI: 1.08-2.41, P = 0.018) was found between CD and a nonsynonymous coding single nucleotide polymorphism (rs6622126) in MORC4. The association between the CLDN2 marker and CD was not replicated in the family-based study. Ulcerative colitis was not associated to any of the single nucleotide polymorphism markers.CONCLUSION: These findings suggest that a variant of the CLDN2-MORC4 region predisposes to CD in a Swedish population.
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| 2. |
- Vandewalle-El Khoury, Peggy, et al.
(författare)
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Detection of antisynthetic mannoside antibodies (ASigmaMA) reveals heterogeneity in the ASCA response of Crohn's disease patients and contributes to differential diagnosis, stratification, and prediction
- 2008
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Ingår i: American Journal of Gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 0002-9270 .- 1572-0241. ; 103:4, s. 949-957
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Anti-S. cerevisiae mannan antibodies (ASCA) are human antibodies associated with Crohn's disease (CD) reacting with Saccharomyces cerevisiae (S. cerevisiae) mannan polymer. As mannan is a complex and variable repertoire of oligomannoses acting as epitopes, we chemically synthesized (Sigma) two major oligomannose epitopes, Man alpha-1,3 Man alpha-1,2 Man (SigmaMan3) and Man alpha-1,3 Man alpha-1,2 Man alpha-1,2 Man (SigmaMan4), and then explored how antisynthetic mannoside antibodies (ASigmaMA) compare with ASCA as markers of CD.METHODS: The study involved different cohorts of CD and ulcerative colitis (UC) patients and healthy controls who had been studied previously in several medical centers in Europe, the United States, and North Africa to determine the clinical value of ASCA in terms of differential diagnosis, evolution of indeterminate colitis (IC), and serotype-phenotype correlations. The comparison of ASigmaMA and ASCA included a total of 1,365 subjects: 772 CD, 261 UC, 43 IC, and 289 controls.RESULTS: The specificity of ASigmaMA was similar to that of ASCA (89% vs 93%), although the sensitivity was lower (38% vs 55%). Unexpectedly, 24% of the CD patients who were negative for ASCA and/or other CD-associated serologic markers were positive for ASigmaMA. ASigmaMA were associated with colonic involvement in CD (odds ratio [OR] 1.609, 95% confidence interval [CI] 1.033-2.506, P = 0.03) and were 100% predictive of CD in patients with IC.CONCLUSIONS: ASigmaMA reveal the heterogeneity of the antioligomannose antibody response in CD patients and increase the sensitivity of CD diagnosis when combined with ASCA. The subset of ASCA-negative CD patients diagnosed by ASigmaMA had preferentially a colonic involvement, which confirms the high predictive value of ASigmaMA for determining IC evolution toward CD.
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| 3. |
- Momozawa, Yukihide, et al.
(författare)
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Resequencing of positional candidates identifies low frequency IL23R coding variants protecting against inflammatory bowel disease
- 2011
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Ingår i: Nature Genetics. - New York : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 43:1, s. 43-47
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified dozens of risk loci for many complex disorders, including Crohn's disease. However, common disease-associated SNPs explain at most ∼20% of the genetic variance for Crohn's disease. Several factors may account for this unexplained heritability, including rare risk variants not adequately tagged thus far in GWAS. That rare susceptibility variants indeed contribute to variation in multifactorial phenotypes has been demonstrated for colorectal cancer, plasma high-density lipoprotein cholesterol levels, blood pressure, type 1 diabetes, hypertriglyceridemia and, in the case of Crohn's disease, for NOD2 (refs. 14,15). Here we describe the use of high-throughput resequencing of DNA pools to search for rare coding variants influencing susceptibility to Crohn's disease in 63 GWAS-identified positional candidate genes. We identify low frequency coding variants conferring protection against inflammatory bowel disease in IL23R, but we conclude that rare coding variants in positional candidates do not make a large contribution to inherited predisposition to Crohn's disease.
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| 4. |
- Zheng, Tenghao, et al.
(författare)
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Human Leukocyte Antigen Signatures as Pathophysiological Discriminants of Microscopic Colitis Subtypes
- 2024
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Ingår i: Journal of Crohn's and Colitis. - : OXFORD UNIV PRESS. - 1873-9946 .- 1876-4479. ; 18:3, s. 349-359
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Microscopic colitis [MC] is currently regarded as an inflammatory bowel disease that manifests as two subtypes: collagenous colitis [CC] and lymphocytic colitis [LC]. Whether these represent a clinical continuum or distinct entities is, however, an open question. Genetic investigations may contribute important insight into their respective pathophysiologies. Methods: We conducted a genome-wide association study [GWAS] meta-analysis in 1498 CC, 373 LC patients, and 13 487 controls from Europe and the USA, combined with publicly available MC GWAS data from UK Biobank and FinnGen [2599 MC cases and 552 343 controls in total]. Human leukocyte antigen [HLA] alleles and polymorphic residues were imputed and tested for association, including conditional analyses for the identification of key causative variants and residues. Genetic correlations with other traits and diagnoses were also studied. Results: We detected strong HLA association with CC, and conditional analyses highlighted the DRB1*03:01 allele and its residues Y26, N77, and R74 as key to this association (best p = 1.4 × 10-23, odds ratio [OR] = 1.96). Nominally significant genetic correlations were detected between CC and pneumonia [rg = 0.77; p = 0.048] and oesophageal diseases [rg = 0.45, p = 0.023]. An additional locus was identified in MC GWAS analyses near the CLEC16A and RMI2 genes on chromosome 16 [rs35099084, p = 2.0 × 10-8, OR = 1.31]. No significant association was detected for LC. Conclusion: Our results suggest CC and LC have distinct pathophysiological underpinnings, characterised by an HLA predisposing role only in CC. This challenges existing classifications, eventually calling for a re-evaluation of the utility of MC umbrella definitions.
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| 5. |
- Agrawal, Manasi, et al.
(författare)
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Inflammatory bowel diseases among first-generation and second-generation immigrants in Denmark : a population-based cohort study
- 2021
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Ingår i: Gut. - : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 70:6, s. 1037-1043
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Our objective was to estimate the relative risk of IBD among first-generation and second-generation immigrants in Denmark compared with native Danes.DESIGN: Using national registries, we established a cohort of Danish residents between 1977 and 2018. Cohort members with known country of birth were followed for Crohn's disease (CD) and ulcerative colitis (UC) diagnoses. Incidence rate ratios (IRRs) served as measures of relative risk and were calculated by log-linear Poisson regression, using rates among native Danes as reference, stratified by IBD risk in parental country of birth, and among first-generation immigrants by age at immigration and duration of stay in Denmark.RESULTS: Among 8.7 million Danes, 4156 first-generation and 898 second-generation immigrants were diagnosed with CD or UC. Overall, comparing first-generation immigrants with native Danes, the IRR was 0.80 (95% CI 0.76 to 0.84) for CD and 0.74 (95% CI 0.71 to 0.77) for UC. The IRR of IBD increased with ≥20 years stay in Denmark. The IRR of CD increased with immigration at ≥40 years of age. Comparing second-generation immigrants with native Danes, the IRR of IBD was 0.97 (95% CI 0.91 to 1.04). There was significant interaction with sex, with higher IRR of IBD in male than in female immigrants.CONCLUSION: Relative to native Danish men and women, IBD risk among first-generation immigrants was lower, reflected the risk in their parental country of birth and increased with ≥20 years stay in Denmark. For second-generation immigrants, relative risk of IBD was lower only among women. These complex patterns suggest the role of environmental IBD risk factors.
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| 6. |
- Amcoff, Karin, 1975-, et al.
(författare)
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Concordance in Anti-OmpC and Anti-I2 Indicate the Influence of Genetic Predisposition : Results of a European Study of Twins with Crohn's Disease
- 2016
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Ingår i: Journal of Crohn's & Colitis. - Oxford, United Kingdom : Oxford University Press. - 1873-9946 .- 1876-4479. ; 10:6, s. 695-702
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: An adaptive immunological response to microbial antigens has been observed in Crohn's disease (CD). Intriguingly, this serological response precedes the diagnosis in some patients and has also been observed in healthy relatives. We aimed to determine whether genetic factors are implicated in this response in a CD twin cohort.Methods: In total, 82 twin pairs (Leuven n = 13, Maastricht n = 8, Örebro n = 61) took part: 81 pairs with CD (concordant monozygotic n = 16, discordant monozygotic n = 22, concordant dizygotic n = 3, discordant dizygotic n = 40) and 1 monozygotic pair with both CD and ulcerative colitis. Serology for Pseudomonas fluorescens-related protein (anti-I2), Escherichia coli outer membrane porin C (anti-OmpC), CBir1flagellin (anti-CBir1) and antibodies to oligomannan (anti-Saccharomyces cerevisiae antibody [ASCA]) was determined by standardized enzyme-linked immunoassay.Results: All markers were more often present in CD twins than in their healthy twin siblings. Using the intraclass correlation coefficient (ICC), agreements in concentrations of anti-OmpC and anti-I2 were observed in discordant monozygotic but not in discordant dizygotic twin pairs with CD (anti-OmpC, ICC 0.80 and -0.02, respectively) and (anti-I2, ICC 0.56 and 0.05, respectively). In contrast, no agreements were found in anti-CBir, immunoglobulin (Ig) G ASCA and ASCA IgA.Conclusions: We show that anti-I2 and anti-CBir1 statuses have specificity for CD and confirm previous reported specificities for anti-OmpC and ASCA. Based on quantitative analyses and observed ICCs, genetics seems to predispose to the anti-OmpC and anti-I2 response but less to ASCA and anti-CBir1 responses.
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| 7. |
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| 8. |
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| 9. |
- Hirten, Robert P., et al.
(författare)
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A Users Guide to De-escalating Immunomodulator and Biologic Therapy in Inflammatory Bowel Disease
- 2020
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Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier. - 1542-3565 .- 1542-7714. ; 18:6, s. 1336-1345
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Forskningsöversikt (refereegranskat)abstract
- De-escalation of immunomodulators and biologic agents in inflammatory bowel disease is frequently discussed with patients and must weigh the risk of continued medical therapy with the risk of disease recurrence. Risk factors for disease flare after withdrawal of inflammatory bowel disease medications such as disease activity at de-escalation, disease prognostic features and prior course of disease have been identified predominately in retrospective studies allowing for risk stratification of patients. This review evaluates the published literature regarding therapeutic de-escalation and provides a framework for physicians to apply this to clinical practice. Prospective trials are underway and planned which should provide further insight into this treatment paradigm and better inform patient selection for this strategy.
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| 10. |
- Hirten, Robert P., et al.
(författare)
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Reply
- 2021
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Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier. - 1542-3565 .- 1542-7714. ; 19:6, s. 1301-1302
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Tidskriftsartikel (refereegranskat)
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