Does calprotectin level identify a subgroup among patients suffering from irritable bowel syndrome? Results of a prospective study

Abstract

Background: Irritable bowel syndrome is a multifactorial disease. Although faecal calprotectin has been shown to be a reliable marker of intestinal inflammation, its role in irritable bowel syndrome remains debated. Objective: The aims of this prospective study were to select a subgroup of irritable bowel syndrome patients and to characterise those patients with high faecal calprotectin by systematic work-up. Methods: Calprotectin levels were determined by enzyme-linked immunosorbent assay test in consecutive irritable bowel syndrome patients fulfilling Rome III criteria in whom normal colonoscopy and appropriate tests had excluded organic disease. Calprotectin levels were compared in irritable bowel syndrome patients, healthy controls and patients with active and quiescent Crohn's disease. When the calprotectin level was higher than 50 mg/g, the absence of ANCA/ASCA antibodies and a normal small bowel examination were required to confirm irritable bowel syndrome diagnosis. Additional explorations included assessment of irritable bowel syndrome severity, anxiety and depression, impact on quality of life, glucose and fructose breath tests, rectal distension test by barostat and quantitative and qualitative assessment of inflammation on colonic biopsies. Results: Among the 93 irritable bowel syndrome patients (73% women; 66.7% with diarrhoea) recruited, 34 (36.6%) had reproducibly elevated calprotectin. Although they tended to be older than those with normal calprotectin (P ¼ 0.06), there were no other differences between the two groups. When elevated, calprotectin was correlated with age (P ¼ 0.03, r ¼ 0.22). Conclusions: Elevated faecal calprotectin was observed in one third of patients in this series, without any significant association with a specific clinical phenotype (except age) or specific abnormalities.

Is fecal calprotectin always normal in children with irritable bowel syndrome?

“…In particular, no research comparing FC concentrations between IBS patients and HCs has been performed in children/adolescents. However, a recent study reported that the mean FC level in adult patients with PI-IBS was significantly higher than the cutoff value and that in a control group without digestive symptoms (90.5±180 μg/g vs. 24.3±16.1 μg/g, P <0.01) [20]. The results of our study also showed that the mean FC concentration in the PI-IBS group was higher than 50 μg/g.…”

Increasing Evidence That Irritable Bowel Syndrome and Functional Gastrointestinal Disorders Have a Microbial Pathogenesis

“…Although calprotectin is primarily used to distinguish IBS from IBD (Chang et al, 2014 ; Banerjee et al, 2015 ), concentrations have been shown to vary within IBS. In a prospective study, fecal calprotectin was elevated in one third of all patients across IBS subtypes (Melchior et al, 2017 ). In addition, a recent study demonstrated that differences in fecal calprotectin concentrations in children discriminated between IBS subtypes and from healthy controls.…”

Fructose and irritable bowel syndrome

“…In animal models, there is an association between fructose intake, increased intestinal permeability and inflammation (94)(95)(96)(97) . However, in humans, fructose malabsorption in IBS patients does not seem to be linked to low-grade inflammation or to increased intestinal permeability (98,99) .…”