Late-Onset Crohn's Disease Is A Subgroup Distinct in Genetic and Behavioral Risk Factors With UC-Like Characteristics

Dietary index based on the Food Standards Agency nutrient profiling system and risk of Crohn's disease and ulcerative colitis

BACKGROUND

Nutri-score is now widely available in food packages in Europe.

AIM

To study the overall nutritional quality of the diet in relation to risks of Crohn's disease (CD) and ulcerative colitis (UC), in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort METHODS: We collected dietary data at baseline from validated food frequency questionnaires. We used a dietary index based on the UK Food Standards Agency modified nutrient profiling system (FSAm-NPS-DI) underlying the Nutri-Score label, to measure the nutritional quality of the diet. We estimated the association between FSAm-NPS-DI score, and CD and UC risks using Cox models stratified by centre, sex and age; and adjusted for smoking status, BMI, physical activity, energy intake, educational level and alcohol intake.

RESULTS

We included 394,255 participants (68.1% women; mean age at recruitment 52.1 years). After a mean follow-up of 13.6 years, there were 184 incident cases of CD and 459 incident cases of UC. Risk of CD was higher in those with a lower nutritional quality, that is higher FSAm-NPS-DI Score (fourth vs. first quartile: aHR: 2.04, 95% CI: 1.24-3.36; p-trend: <0.01). Among items of the FSAm-NPS-DI Score, low intakes of dietary fibre and fruits/vegetables/legumes/nuts were associated with higher risk of CD. Nutritional quality was not associated with risk of UC (fourth vs. first quartile of the FSAm-NPS-DI Score: aHR: 0.91, 95% CI: 0.69-1.21; p-trend: 0.76).

CONCLUSIONS

A diet with low nutritional quality as measured by the FSAm-NPS-DI Score is associated with a higher risk of CD but not UC.

Age determines the risk of familial inflammatory bowel disease-A nationwide study

BACKGROUND AND AIMS

To estimate familial aggregation of inflammatory bowel disease (IBD), we performed a nationwide, case-control study and examined the odds for patients with IBD (vs controls) to have a first-degree relative (FDR) with IBD, by age of diagnosis, type of family history and IBD subtype. To assess the incidence of future IBD in relatives of incident IBD patients, we performed a cohort study.

METHODS

Individuals diagnosed with IBD (N = 50,667) between 2003 and 2017 with at least one FDR were identified from Swedish national registers and compared to general population controls (N = 506,720) with at least one FDR. We used logistic regression to calculate adjusted odds ratios (ORs) and Cox regression to estimate hazard ratios (HRs).

RESULTS

Compared to controls, IBD cases more often had a mother (3.0% vs 0.9%, OR = 3.5; 95% CI: 3.3-3.7), father (2.9% vs 0.8%, OR = 3.5; 95% CI: 3.3-3.7), full sibling (5.3% vs 1.5%, OR = 3.6; 95% CI: 3.4-3.8) and child (2.4% vs 0.9%, OR = 2.6; 95% CI: 2.4-2.8) with IBD. The strength of association increased with the number of affected FDRs and was modified by subtype of IBD and age of diagnosis. Highest ORs were observed for paediatric IBD among paediatric-onset Crohn's disease (OR = 10.6; 95% CI: 8.2-13.5) and paediatric-onset ulcerative colitis (OR = 8.4; 95% CI: 6.4-10.9) cases. The 10-year cumulative incidence of IBD was 1.7% in full-siblings of incident IBD patients vs 0.4% among full-siblings of reference individuals.

CONCLUSION

The variations in the strength of familial IBD and future risk of IBD in FDRs support differences in genetic predisposition and call for targeted approaches in potential screening programmes.

Meta-Analysis of IBD Gut Samples Gene Expression Identifies Specific Markers of Ileal and Colonic Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs) are characterized by chronic inflammation and tissue damages in limited segments of the digestive tract. Pathogenesis in the tissue and mucosal inflammation probably differs according to disease location. Our aim was to further analyze transcriptomic profiles in different locations of IBD, differentiating ulcerative colitis (UC), colonic Crohn's disease (CD), ileal CD, and pouchitis, with respect to normal colonic and ileal mucosa. We thus performed a meta-analysis focusing on specific transcriptomic signatures of ileal and colonic diseases.

METHODS

We identified 5 cohorts with available transcriptomic data in ileal or colonic samples from active IBD and non-IBD control samples. The meta-analysis was performed on 1047 samples. In each cohort separately, we compared gene expression in CD ileitis and normal ileum; in CD colitis, UC, and normal colon; and finally in pouchitis and normal ileum.

RESULTS

We identified specific markers of ileal (FOLH1, CA2) and colonic (REG3A) inflammation and showed that, with disease, some cells from the ileum start to express colonic markers. We confirmed by immunohistochemistry that these markers were specifically present in ileal or colonic diseases. We highlighted that, overall, colonic CD resembles UC and is distinct from ileal CD, which is in turn closer to pouchitis.

CONCLUSIONS

We demonstrated that ileal and colonic diseases exhibit specific signatures, independent of their initial clinical classification. This supports molecular, rather than clinical, disease stratification, and may be used to design drugs specifically targeting ileal or colonic diseases.

Time to Revisit Disease Classification in Inflammatory Bowel Disease: Is the Current Classification of Inflammatory Bowel Disease Good Enough for Optimal Clinical Management?

Inflammatory bowel disease (IBD), historically subdivided into Crohn's disease and ulcerative colitis, is a very heterogeneous condition. While the tendency in medicine is to try to reduce complexity, IBD is a disease that cannot justify a one-size-fits-all principle. Our current clinical classification tools are suboptimal and need further refinement to capture, at least in part, the variety of phenotypes encountered in daily clinical practice. Although these revised classification tools alone will not be sufficient and should be complemented by more detailed molecular subclassifications, optimized clinical phenotypes can contribute to improved trial designs, future translational research approaches, and better treatment outcomes. In the current review, we discuss key clinical features important in IBD disease heterogeneity, tackle limitations of the current classification systems, propose some potential improvements, and raise priorities for future research in this domain.

Learning Longitudinal Patterns and Subtypes of Pediatric Crohn Disease Treated With Infliximab via Trajectory Cluster Analysis

BACKGROUND

The objective of this study is to identify subgroups of pediatric Crohn disease (CD) who had differential responses to the infliximab treatment through trajectory cluster analysis of disease activity using data from electronic health records.

METHODS

We conducted a retrospective study of 295 pediatric patients with CD who had been treated with infliximab for a minimum of one year at the Center for Inflammatory Bowel Disease at The Children's Hospital of Philadelphia between January 2010 and December 2017. The evolution of disease was described, and subgroups of patients were identified using trajectory analysis of longitudinal data of C-reactive protein (CRP). We compared patient characteristics, biomarker for disease activity, and long-term surgical outcomes across subgroups. Cox regression models were used to evaluate the added value of the subgroup classification to baseline phenotype and location in prediction of long-term surgical outcomes.

RESULTS

We identified three subgroups of patients with differential relapse-and-remission profiles (n = 33, 65 and 197 from subgroup 1 to 3), which represented patients with a higher risk of infliximab non-response, with infliximab response but with occasional disease flares, and patients with long-term response. Patients with the best treatment response had a significantly lower frequency of complicated disease phenotypes (P = 0.01), including perianal involvement (P = 0.05), lower baseline CRP (P < 0.01) and calprotectin (P = 0.01), and lowest risk of IBD-related gastrointestinal surgery within 10 years of starting treatment (P < 0.01).

CONCLUSIONS

Readily available longitudinal data from electronic health records can be leveraged to provide deeper characterization of treatment response in pediatric CD.

Does the location of inflammatory lesions in the gastrointestinal tract determine the clinical course of Crohn’s disease?

Introduction

Crohn’s disease (CD) is a chronic, inflammatory bowel disease that can affect any part of the digestive system. The ileocecal region is most commonly involved. Recently, there have been reports about Crohn’s disease isolated to the colon, which may be associated with different clinical behaviour and the need for various treatment options.

Materials/Methods

The study included 305 patients with CD, 171 women (56%) and 134 men (44%), hospitalized at the Department of Gastroenterology, University Hospital in Lodz. Among them, a group of 101 patients was identified with a lesion location only in the colon (L2) and 204 in the small intestine and colon (L1 and L3). An attempt was made to analyze patients with CD in terms of demographic data, clinical behavior of the disease and location of inflammatory lesions.

Results

Among the features distinguishing the location of inflammatory lesions isolated to the colon (L2), statistically significantly less frequent occurrence of stenoses (21% at L2 location to 79% at L3, p <0.01) was observed compared to other locations. Moreover, patients with location of L2 lesions required surgery less frequently (27% with L2 vs. 73% L1 with L3, p <0.05). It was also demonstrated that among all the subjects, 42 patients underwent appendectomy before the diagnosis of CD, which constituted 19% of the L2 group patients to 81% of the L1 and L3 group (p <0.05).

Conclusions

In CD there is a great diversity in the clinical behavior of the disease, which is undoubtedly related to its location. The obtained results indicate that in the group of patients with the location isolated to the colon, stenoses are less common and patients require surgery less frequently.

Transcriptomic analysis of ileal tissue from Crohn's disease patients identifies extracellular matrix genes that distinguish individuals by age at diagnosis

Crohn's disease (CD) is a debilitating gastrointestinal (GI) disorder that can impact the entirety of the GI tract. While substantial progress has been made in the medical management of CD, it remains incurable, frequently relapses, and is a significant financial and medical burden. The pathophysiology of CD is not well understood, but it is thought to arise in genetically susceptible individuals upon an environmental insult. Further elucidation of the disease etiology promises to expose additional therapeutic avenues, with the hope of reducing the burden of CD. One approach to understanding disease pathophysiology is to identify clinically relevant molecular disease subsets by using transcriptomics. In this report, we use hierarchical clustering of the ileal transcriptomes of 34 patients and identify two CD subsets. Clinically, these clusters differed in the age of the patients at CD diagnosis, suggesting that age of onset affects disease pathophysiology. The clusters were segregated by three major gene ontology categories: developmental processes, ion homeostasis, and the immune response. Of the genes constituting the immune system category, expression of extracellular matrix-associated genes, COL4A1, S100A9, ADAMTS2, SERPINE1, and FCN1, exhibits the strongest correlation with an individual's age at CD diagnosis. Together these findings demonstrate that transcriptional profiling is a powerful approach to subclassify CD patients.

Adherence to a Mediterranean diet is associated with a lower risk of later-onset Crohn's disease: results from two large prospective cohort studies

OBJECTIVE

To examine the relationship between Mediterranean diet and risk of later-onset Crohn's disease (CD) or ulcerative colitis (UC).

DESIGN

We conducted a prospective cohort study of 83 147 participants (age range: 45-79 years) enrolled in the Cohort of Swedish Men and Swedish Mammography Cohort. A validated food frequency questionnaire was used to calculate an adherence score to a modified Mediterranean diet (mMED) at baseline in 1997. Incident diagnoses of CD and UC were ascertained from the Swedish Patient Register. We used Cox proportional hazards modelling to calculate HRs and 95% CI.

RESULTS

Through December of 2017, we confirmed 164 incident cases of CD and 395 incident cases of UC with an average follow-up of 17 years. Higher mMED score was associated with a lower risk of CD (P_trend=0.03) but not UC (P_trend=0.61). Compared with participants in the lowest category of mMED score (0-2), there was a statistically significant lower risk of CD (HR=0.42, 95% CI 0.22 to 0.80) but not UC (HR=1.08, 95% CI 0.74 to 1.58). These associations were not modified by age, sex, education level, body mass index or smoking (all P_interaction >0.30). The prevalence of poor adherence to a Mediterranean diet (mMED score=0-2) was 27% in our cohorts, conferring a population attributable risk of 12% for later-onset CD.

CONCLUSION

In two prospective studies, greater adherence to a Mediterranean diet was associated with a significantly lower risk of later-onset CD.

Challenges of Clustering Multimodal Clinical Data: Review of Applications in Asthma Subtyping

Background

In the current era of personalized medicine, there is increasing interest in understanding the heterogeneity in disease populations. Cluster analysis is a method commonly used to identify subtypes in heterogeneous disease populations. The clinical data used in such applications are typically multimodal, which can make the application of traditional cluster analysis methods challenging.

Objective

This study aimed to review the research literature on the application of clustering multimodal clinical data to identify asthma subtypes. We assessed common problems and shortcomings in the application of cluster analysis methods in determining asthma subtypes, such that they can be brought to the attention of the research community and avoided in future studies.

Methods

We searched PubMed and Scopus bibliographic databases with terms related to cluster analysis and asthma to identify studies that applied dissimilarity-based cluster analysis methods. We recorded the analytic methods used in each study at each step of the cluster analysis process.

Results

Our literature search identified 63 studies that applied cluster analysis to multimodal clinical data to identify asthma subtypes. The features fed into the cluster algorithms were of a mixed type in 47 (75%) studies and continuous in 12 (19%), and the feature type was unclear in the remaining 4 (6%) studies. A total of 23 (37%) studies used hierarchical clustering with Ward linkage, and 22 (35%) studies used k-means clustering. Of these 45 studies, 39 had mixed-type features, but only 5 specified dissimilarity measures that could handle mixed-type features. A further 9 (14%) studies used a preclustering step to create small clusters to feed on a hierarchical method. The original sample sizes in these 9 studies ranged from 84 to 349. The remaining studies used hierarchical clustering with other linkages (n=3), medoid-based methods (n=3), spectral clustering (n=1), and multiple kernel k-means clustering (n=1), and in 1 study, the methods were unclear. Of 63 studies, 54 (86%) explained the methods used to determine the number of clusters, 24 (38%) studies tested the quality of their cluster solution, and 11 (17%) studies tested the stability of their solution. Reporting of the cluster analysis was generally poor in terms of the methods employed and their justification.

Conclusions

This review highlights common issues in the application of cluster analysis to multimodal clinical data to identify asthma subtypes. Some of these issues were related to the multimodal nature of the data, but many were more general issues in the application of cluster analysis. Although cluster analysis may be a useful tool for investigating disease subtypes, we recommend that future studies carefully consider the implications of clustering multimodal data, the cluster analysis process itself, and the reporting of methods to facilitate replication and interpretation of findings.

Should We Divide Crohn's Disease Into Ileum-Dominant and Isolated Colonic Diseases?

Crohn's disease (CD) is an inflammatory bowel disease that can involve any region of the gastrointestinal tract. First described in 1932 as terminal ileitis or regional enteritis, it predominately involves the ileum with or without colonic involvement. Isolated colonic CD was first described in 1960 and since then the phenotypic classification of CD has evolved to stratify patients into isolated ileal, ileocolonic, or isolated colonic involvement. In the current review we evaluate the published literature regarding differences in epidemiology, natural history, pathogenesis, response to therapy, and disease monitoring, when stratified by disease location. Based on the available evidence consideration could be given to a new classification for CD, which splits it into ileum dominant (isolated ileal and ileocolonic) and isolated colonic disease. This may allow for a more optimized approach to clinical care and scientific research for CD.

Novel association of SNP rs479200 in EGLN1 gene with predisposition to preeclampsia

OBJECTIVES

Placental hypoxia is a hallmark of preeclampsia. SNP rs479200 in the EGLN1 gene is associated with reduced responsiveness to hypoxia. Whether this translates into an association between SNP rs479200 and preeclampsia is not known. We evaluated the association of SNP rs479200 (T>C) with the risk of preeclampsia.

METHODS

This case-control study involved 600 pregnant women of whom 300 were preeclamptic and 300 were normotensive. SNP rs479200 was genotyped by PCR-RFLP method.

RESULT

Minor allele frequency was 44% in preeclamptic women and 53% in normotensive pregnant women (P = 1.8 × 10^-3; odds ratio = 1.43). The odds ratio was heterogeneous when compared after categorization of the preeclamptic group into clinical sub-groups. The association was significant with both mild (P = 6.2 × 10^-5) and severe (3.8 × 10^-3) preeclampsia. However, the odds ratio was 0.52 for mild preeclampsia and 1.43 for severe preeclampsia.

CONCLUSION

The minor allele of SNP rs479200 is associated with the predisposition to preeclampsia. This association underlines the importance of oxygen sensing in the pathogenesis of preeclampsia.