The results indicate a marked rise in the incidence of CD in contrast to no increase in UC in South-Eastern Norway, compared with the figures from the last 15 years. Time from onset of symptoms to diagnosis still represents a challenge for early characterization in IBD.

In UC, both biochemical and fecal markers are related to disease activity and extent of disease, whereas in CD, the fecal calprotectin concentration is a reliable marker of mucosal affection, but not for systemic disease activity.

In this study, we describe a specific decrease in HD-5 and TCF-4 mRNA expression levels in children with ileal CD. In the small intestine, this decrease was independent of current inflammation, whereas inflammation seems to induce Paneth cell metaplasia in the colon. Our data extend the hypothesis of an important role of antimicrobial host defense in pediatric CD patients.

Mucosal numbers of Foxp3(+) Tregs and activated (CD25+) macrophages are elevated in both pediatric and adult ileal CD. The greater increase of ileal Foxp3+ Tregs in pediatric CD than in adult CD might contribute to the relatively less frequent phenotype of isolated ileal enteritis in CD children.

As many as 30% to 40% of locally advanced rectal cancer (LARC) patients experience metastatic progression of the disease. Recognizing the potential of the genetic cargo in tumor-derived exosomes, we hypothesized that plasma exosomal microRNA (miRNA) may reflect biological aggressiveness in LARC and provide new markers for rectal cancer aggressiveness and risk stratification. In a prospective LARC cohort ( NCT01816607 ), plasma samples were collected from 29 patients at the time of diagnosis, before neoadjuvant therapy and surgery. Exosomes, precipitated from plasma using a commercial kit, were verified by cryo-electron microscopy, nanoparticle tracking analysis, and western blotting. Expression of exosomal miRNAs was profiled using a miRCURY LNA miRNA microarray and validation of six miRNAs associated with pathological and clinical end-points was undertaken in plasma collected at the time of diagnosis from 64 patients in an independent prospective LARC cohort ( NCT00278694 ). In both cohorts, exosomal miR-141-3p and miR-375 were higher in patients with synchronous liver metastasis than in those without ( P = .010 and P = .017 respectively in the investigative cohort, and P < .001 for both in the validation cohort). Further , high exosomal miR-141-3p was associated with post-operative metastatic liver progression in the investigative cohort ( P = .034). Because both miRNAs are associated with tumor angiogenesis and immune modulation, we propose that these miRNAs in circulating exosomes may reflect rectal cancer aggressiveness and accordingly be candidate biomarkers for further investigations.