Is Prevention the Best Way to Modify Inflammatory Bowel Disease? How Close Are We?

Transcriptome analysis identifies genetic risk markers and explores the pathogenesis for inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable and disabling bowel disease driven by multiple risk factors that severely limit patients' quality of life. We integrated the RNA-sequencing data of 1238 IBD patients, and investigated the pathogenesis of IBD by combining transcriptional element prediction analysis and immune-related analysis. Here, we first determined that KIAA1109 is inhibited in IBD patients. The expression of KIAA1109 and NOD2, the key receptor of NOD-like receptors, showed a negative correlation. The NOD-like receptor signaling pathway is activated and exerts transcriptional regulation on the chemokines CXCL1 and CXCL2 through the activation of the transcription factors NFκB and AP1. Analysis of immune infiltration revealed that the expression of chemokines CXCL1 and CXCL2 may regulate the inflammatory response induced by immune cells. These findings suggest that the KIAA1109-NOD2-NFκB/AP1-CXCL1/CXCL2 regulatory axis is the molecular mechanism of IBD pathogenesis, which will provide a new perspective for the diagnosis, treatment and management of IBD patients.

Baseline Clinical Factors Are Associated With Risk of Complications in Crohn's Disease: Appraisal of the American Gastroenterological Association Clinical Care Pathway

INTRODUCTION

The American Gastroenterological Association (AGA) has compiled risk factors that may be predictive of disease complications in Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to evaluate the performance of the AGA risk factors for risk stratification in UC and CD.

METHODS

We included participants of 2 cohorts: the Ocean State Crohn's and Colitis Area Registry cohort and the Mayo Clinic cohort. Baseline clinical risk factors were extracted according to the AGA pathway. Our primary end point was defined as follows: (i) any inflammatory bowel disease related-hospitalization, (ii) any inflammatory bowel disease-related bowel surgery, or (iii) any progression of disease. We analyzed the association of the number of AGA risk factors with our end point. Statistical multivariable modeling was performed with Cox proportional hazards model.

RESULTS

A total of 412 patients with CD were included. Comparing ≥3 risk factors with 0-1 risk factor, we found a significantly increased risk of complications in both the Ocean State Crohn's and Colitis Area Registry cohort (hazard ratio [HR] 2.75, 95% confidence interval 1.71-4.41) and Mayo Clinic cohort (HR 2.07, 95% confidence interval 1.11-3.84). Diagnosis at younger age (HR 2.07), perianal disease (HR 1.99), and B2/B3 behavior (HR 1.92) were significantly associated with disease complications. We did not observe a consistent association between number of risk factors nor any specific individual risk factors and risk of disease complications in the 265 patients with UC included.

DISCUSSION

We found a significant association between the number of AGA risk factors and the risk of disease complication in CD; this association was not significant in UC. The presence of ≥ 3 risk factors in CD leads to the highest risk of complications. The AGA care pathway is a useful tool to stratify patients who are at higher risk of disease complications in patients with CD.

Medication-Wide Study: Exploring Medication Use 10 Years Before a Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

There is growing interest in the prediagnostic phase of inflammatory bowel disease (IBD) and in the overlap of IBD with other diseases. We described and compared use of any prescription medication between individuals with and without IBD in a 10-year period preceding diagnosis.

METHODS

Based on cross-linked nationwide registers, we identified 29,219 individuals diagnosed with IBD in Denmark between 2005 and 2018 and matched to 292,190 IBD-free individuals. The primary outcome was use of any prescription medication in years 1-10 before IBD diagnosis/matching date. Participants were considered as medication users if they redeemed ≥1 prescription for any medication in the World Health Organization Anatomical Therapeutic Chemical (ATC) main groups or subgroups before diagnosis/matching.

RESULTS

The IBD population had a universally increased use of medications compared with the matched population before IBD diagnosis. At 10 years before diagnosis, the proportion of users was 1.1-fold to 1.8-fold higher in the IBD population in 12 of 14 ATC main groups of medication ( P -value < 0.0001). This applied across age, sex, and IBD subtypes, although it was the most pronounced for Crohn's disease (CD). Two years before diagnosis, the IBD population had a steep increase in medication use for several organ systems. When analyzing therapeutic subgroups of medication, the CD population exhibited 2.7, 2.3, 1.9, and 1.9 times more users of immunosuppressants, antianemic preparations, analgesics, and psycholeptics, respectively, than the matched population 10 years before diagnosis ( P -value < 0.0001).

DISCUSSION

Our findings demonstrate universally increased medication use years before IBD, especially CD, diagnosis and indicates multiorgan involvement in IBD.

Understanding the molecular mechanisms of anti-trafficking therapies and their clinical relevance in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), a combination of dysbiosis, increased intestinal permeability, and insufficient regulatory responses facilitate the development of chronic inflammation, which is driven by a complex interplay between the mucosal immune system and the environment and sustained by immune priming and ongoing cellular recruitment to the gut. The localization of immune cells is mediated by their expression of chemokine receptors and integrins, which bind to chemokines and adhesion molecules, respectively. In this article, we review the mechanisms of action of anti-trafficking therapies for IBD and consider clinical observations in the context of the different mechanisms of action. Furthermore, we discuss the evolution of molecular resistance to anti-cytokines, in which the composition of immune cells in the gut changes in response to treatment, and the potential implications of this for treatment sequencing. Lastly, we discuss the relevance of mechanism of action to combination therapy for IBD.

Implications of the changing epidemiology of inflammatory bowel disease in a changing world

The epidemiology of inflammatory bowel disease (IBD) has undergone considerable shifts since its emergence in the Western world over a century ago, especially in the last few decades, with increasing global burden of disease. IBD incidence continues to rise in developed countries in all age groups which is contributing to compounding prevalence. Further, IBD incidence is rising sharply in Asia and other recently developed and developing countries. In this review, we discuss the implications of changing trends of IBD epidemiology. First, changing patterns provide insights into IBD causes, as they occur concurrent with shifts in the environment, cultures, and attitudes. Understanding the impact of the environment on IBD risk can help towards prediction and prevention strategies. Second, we must prepare healthcare systems for the rising burden of IBD and address it at various levels towards improving outcomes and health, overall.

Neutralizing Anti-Granulocyte Macrophage-Colony Stimulating Factor Autoantibodies Recognize Post-Translational Glycosylations on Granulocyte Macrophage-Colony Stimulating Factor Years Before Diagnosis and Predict Complicated Crohn's Disease

BACKGROUND & AIMS

Anti-granulocyte macrophage-colony stimulating factor autoantibodies (aGMAbs) are detected in patients with ileal Crohn's disease (CD). Their induction and mode of action during or before disease are not well understood. We aimed to investigate the underlying mechanisms associated with aGMAb induction, from functional orientation to recognized epitopes, for their impact on intestinal immune homeostasis and use as a predictive biomarker for complicated CD.

METHODS

We characterized using enzyme-linked immunosorbent assay naturally occurring aGMAbs in longitudinal serum samples from patients archived before the diagnosis of CD (n = 220) as well as from 400 healthy individuals (matched controls) as part of the US Defense Medical Surveillance System. We used biochemical, cellular, and transcriptional analysis to uncover a mechanism that governs the impaired immune balance in CD mucosa after diagnosis.

RESULTS

Neutralizing aGMAbs were found to be specific for post-translational glycosylation on granulocyte macrophage-colony stimulating factor (GM-CSF), detectable years before diagnosis, and associated with complicated CD at presentation. Glycosylation of GM-CSF was altered in patients with CD, and aGMAb affected myeloid homeostasis and promoted group 1 innate lymphoid cells. Perturbations in immune homeostasis preceded the diagnosis in the serum of patients with CD presenting with aGMAb and were detectable in the noninflamed CD mucosa.

CONCLUSIONS

Anti-GMAbs predict the diagnosis of complicated CD long before the diagnosis of disease, recognize uniquely glycosylated epitopes, and impair myeloid cell and innate lymphoid cell balance associated with altered intestinal immune homeostasis.