What does the IBD patient hide in the upper gastrointestinal tract?

Tools for the Diagnosis and Management of Crohn's Disease

Numerous tools have emerged over recent decades to aid in the increasingly complex management of patients with Crohn's disease (CD) beyond endoscopy, including video capsule endoscopy, magnetic resonance enterography, computed tomography enterography, a variety of biomarkers, and even wearable biosensors and smartphone applications. These tools have allowed for a more sophisticated and less invasive complementary approach to the evaluation of disease activity and treatment response in patients with CD. This article details the characteristics, practical application, and limitations of these various modalities and discusses how updated guidelines are now incorporating many of them into a treat-to-target strategy.

Endoscopy in inflammatory bowel disease: Role in diagnosis, management, and treatment

Endoscopy plays a fundamental role in the diagnosis, management, and treatment of inflammatory bowel disease (IBD). Colonoscopy, flexible sigmoidoscopy, and esophagogastroduodenoscopy have long been used in the care of patients with IBD. As endoscopic technologies have progressed, tools such as endoscopic ultrasound, capsule endoscopy, and balloon-assisted enteroscopy have expanded the role of endoscopy in IBD. Furthermore, chromoendoscopy has enhanced our ability to detect dysplasia in IBD. In this review article, we will focus on the roles, indications, and limitations of these tools in IBD. We will also discuss the most commonly used endoscopic scoring systems, as well as special considerations in post-surgical patients. Lastly, we will discuss the role of endoscopy in the diagnosis and management of fistulae and strictures.

Younger age at diagnosis is associated with panenteric, but not more aggressive, Crohn's disease

BACKGROUND & AIMS

Crohn's disease (CD) diagnosed in pediatric patients has been reported to have a more aggressive phenotype and course, with a greater prevalence of upper gastrointestinal involvement, than in adults. However, studies have not accounted for differences in diagnostic tests. We aimed to discern whether, in fact, CD diagnosed in childhood has a different outcome than CD diagnosed in adults.

METHODS

We performed comprehensive medical chart reviews of 571 patients with CD (451 with complete data) who were followed in a single referral inflammatory bowel disease clinic in Winnipeg, Canada, from 1993-2012. For specific time intervals, we determined types and numbers of imaging studies performed and parameters of disease phenotype, including age at diagnosis according to the Montreal classification (A1 diagnosed <17 years of age, A2 diagnosed 17-40 years, and A3 diagnosed >40 years).

RESULTS

Within 1 year of diagnosis, a higher proportion of A1 patients had upper gastrointestinal involvement and ileocolonic (L3) disease than A2 or A3 patients. These differences could be partly accounted for by the diagnostic tests performed during this time period. Although A1 patients underwent more extensive imaging studies, they had a lower prevalence of complicated disease, particularly compared with A3 patients. After a median follow-up period of 11.1 years, complicated disease behavior (B2 [structuring] or B3 [penetrating]) was similar among the 3 groups. Nonetheless, at the end of the study period, rates of inflammatory bowel disease-related abdominal surgery were significantly lower for A1 than A2 patients (odds ratio, 0.63; 95% confidence interval, 0.41-0.98) but not for A3 patients (odds ratio, 0.71; 95% confidence interval, 0.40-1.27).

CONCLUSIONS

On the basis of a database analysis of different age groups of patients with CD, studies of disease phenotypes among different cohorts should account for different patterns of diagnostic imaging evaluation. Our data show that although children are at increased risk of panenteric disease, they are not more likely to have more complicated disease or undergo surgery than adults.

Challenging question: can we diagnose Crohn's disease without histology?

No single test is diagnostic of Crohn's disease (CD). In the presence of a compatible clinical presentation, diagnosis is by convention confirmed by a combination of imaging, serologic, endoscopic and histologic investigations. This diagnostic recommendation should be maintained, even though histology is often 'compatible with' rather than 'diagnostic of' suspected CD. The importance of histology varies depending on the specific sites of macroscopic disease. Histology is particularly important in distinguishing type of inflammatory bowel disease, when the colon predominantly is involved, and in confirming CD when macroscopic disease is atypically located.

Lymphocytic esophagitis: a possible manifestation of pediatric upper gastrointestinal Crohn's disease

BACKGROUND

Lymphocytic esophagitis (LE) is histologically defined by marked esophageal lymphocytosis with no or only rare intraepithelial granulocytes. This study was performed to investigate the association between LE and pediatric Crohn's disease (CD).

METHODS

Blinded retrospective morphologic analysis was performed on gastrointestinal biopsies from pediatric patients with an established diagnosis of CD (n = 60) and ulcerative colitis (UC; n = 30), as well as a spectrum of non-inflammatory bowel disease (IBD) patients (n = 38). The highest density of intraepithelial lymphocytes (IEL), neutrophils (IEN), and eosinophils (IEE) per high power field (hpf; 40×) were counted. LE was defined as >50 IEL/hpf and a ratio of >50:1 IEL to intraepithelial granulocytes (IEG).

RESULTS

LE was identified in 17/60 patients with CD, and only 2/30 patients with UC and 1/38 non-IBD control patients; P = 0.0263 (CD versus UC) and P = 0.0002 (CD versus non-CD). In all, 6/60 CD patients had esophagitis with granulomas and three of these met the diagnostic criteria for LE. There was no difference in the incidence of upper gastrointestinal (UGI) symptoms between the CD patients with LE (7/17, 41%) and CD patients with esophagitis with granulomas (3/6; P = 1.0).

CONCLUSIONS

The histologic diagnosis of LE is associated with pediatric CD and was found in 28% of CD patients. If LE is identified in pediatric CD, it is likely a manifestation of UGI-CD rather than esophagitis due to other etiologies or a variant of normal.

Protease-activated receptors: novel central role in modulation of gastric functions

Protease-activated receptors (PARs) are members of a subfamily of G-protein-coupled receptors that regulate diverse cell functions in response to proteolytic cleavage of an anchored peptide domain that acts as a 'tethered' receptor-activating ligand. PAR-1 and PAR-2 in particular are present throughout the gastrointestinal (GI) tract and play prominent roles in the regulation of GI epithelial function, motility, inflammation and nociception. In a recent article in Neurogastroenterology and Motility, Wang et al. demonstrate, for the first time, that PAR-1 and PAR-2 are present on preganglionic parasympathetic neurons within the rat brainstem. As in other cellular systems, proteases such as thrombin and trypsin activate PAR-1 and PAR-2 on neurons of the dorsal motor nucleus of the vagus (DMV), leading to an increase in intracellular calcium levels via signal transduction mechanisms involving activation of phospholipase C and inositol triphosphate (IP3). The authors also report that the level of PAR-1 and PAR-2 transcripts in DMV tissue is increased following experimental colitis, suggesting that inflammatory conditions may modulate neuronal behavior or induce plasticity within central vagal neurocircuits. It seems reasonable to hypothesize, therefore, that the activity and behavior of vagal efferent motoneurons may be modulated directly by local and/or systemic proteases released during inflammation. This, in turn, may contribute to the increased incidence of functional GI disorders, including gastric dysmotility, delayed emptying and gastritis observed in patients with inflammatory bowel diseases.