Patients with dyspepsia have impaired mucosal integrity both in the duodenum and jejunum: in vivo assessment of small bowel mucosal integrity using baseline impedance

BACKGROUND

Recent studies reported that impaired proximal duodenal mucosa, assessed by duodenal biopsy, could play an important role in the development of dyspeptic symptoms. The aims of this study were (a) to develop a method to measure "in vivo" duodenal and jejunal baseline impedance (BI) and (b) to assess small bowel mucosal integrity in patients with functional dyspepsia (FD) and healthy controls (HC).

METHODS

We recruited 16 patients with FD and 15 HC. All subjects underwent ambulatory duodeno-jejunal manometry combined with impedance (HRM/Z), BI were determined by measuring impedance immediately after the passage of nocturnal migrating motor complex (MMC) phase IIIs.

RESULTS

The number of MMC phase IIIs in FD was significantly lower than that in HC (2.6 ± 1.4 vs 4.8 ± 1.7, p < 0.001). The BI in patients was significantly lower than that in HC in D1(164.2 ± 59.8 Ω in FD and 243.1 ± 40.5 Ω in HC, p = 0.0061), D2 (191.2 ± 34.1 and 256.5 ± 91.4 Ω, p = 0.01), D3 (214.0 ± 76.9 and 278.1 ± 45.3 Ω, p = 0.009), D4 (270.8 ± 54.2 and 351.8 ± 50.2 Ω, p < 0.001), and J1 (312.2 ± 55.4 and 379.3 ± 38.3 Ω, p = 0.001).

CONCLUSIONS

This is the first study reporting the duodenal and jejunal BI in vivo. The results have shown significantly lowered BI in the proximal small intestine in patients with FD compared to HC. Furthermore it suggests that measurements of small bowel BI could be used as a biomarker for diagnosis and follow up of patients with FD.

Correlation between morphological expansion and impairment of intra- and prelesionary motility in inflammatory small bowel lesions in patients with Crohn's disease - preliminary data

INTRODUCTION

The aim of this study is to investigate if alterations of intra- and prelesionary motility in inflamed small-bowel segments correlate with length, wall-thickness and prelesionary dilatation of inflammatory small bowel lesions in patients suffering from Crohn's disease assessed with MRI.

METHODS AND MATERIALS

This retrospective IRB approved study included 25 patients (12 males, 18-77y) with inflammatory lesions examined using (MRE) magnetic resonance imaging enterography. Cine MRE was performed using a coronal 2D steady-state free precession sequence (TR 2.9, TE 1.25) on a 1.5T MRI scanner. Small bowel motility was examined using a dedicated MR-motility assessment software (Motasso, Vers. 1.0, Sohard AG, Bern, Switzerland). Motility patterns (contraction frequency, relative occlusion rate and mean diameter) were assessed in correlation to wall thickness, length and prelesionary dilatation of the lesions. Statistical analysis was performed by calculation of the Pearson's-Correlation coefficient.

RESULTS

The length of the inflammatory segments, the wall thickening and prelesionary dilatation did not correlate with the frequency of the contractions (r=0.17, p=0.477; r=0.316, p=0.123; r=0.161, p=0.441) or the impairment of luminal occlusion (r=0.274, p=0.184; r=0.199, p=.0339; r=0.015, p=0.945) and only the prelesionary dilatation (r=0.410, p=0.042) correlated to the mean luminal diameter of the segment.

CONCLUSION

The degree of motility impairment within inflammatory small bowel lesions does not significantly correlate with the extent of the lesion but with the motility measured in prelesionary, non-affected segments, suggesting an interdependent functional aspect of inflammation even in morphologically non-affected small bowel segments.

Automated small bowel motility measurements in MRI using 2D coronal slices - does the intrasegmental location matter? A pilot study

INTRODUCTION

To evaluate if small bowel motility analyses are influenced by the positioning of the 2D-cross-section measurement point within the lumen.

MATERIALS AND METHODS

Forty-four small-bowel motility measurements were included in this institutional review board-approved, prospective study. Motility sequences (Dixon-dynFFE; Temporal-resolution 1s, breath-hold) of the ileocecal region were acquired using magnetic resonance imaging (3.0-Tesla; Ingenia-Philips). Motility was analyzed in three different compartments of the small bowel lumen (ventral, central, dorsal). Curve characteristics were statistically compared.

RESULTS

Mean luminal diameter, contraction amplitudes (P>.05) and the extent of luminal occlusion during contraction (P=.11) did not differ significantly between the compartments (ventral/central/dorsal) of the bowel lumen.

CONCLUSION

Quantitative motility parameters are not substantially influenced by the choice of cross sections on coronal planes as long as the segment is visible throughout the measurement.

Association of serotonin transporter promoter polymorphism (5-HTTLPR) with orocecal transit time in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a multifactorial disorder with altered intestinal motility, secretion, and sensation. Serotonin (5-HT) stimulates gut motility and alters serotonin signaling that may lead to both intestinal and extraintestinal symptoms in IBS.

AIM

The aim of this study was to examine the association of serotonin transporter gene promoter polymorphism (5-HTTLPR) in IBS with orocecal transit time (OCTT) measured by lactulose hydrogen breath test.

METHOD

This prospective case-control study included 151 IBS patients (mean±SD 37.4±11.6 years, median 36, range 19-68). Ninety-two patients were diarrhea-predominant IBS (D-IBS), 44 constipation-predominant IBS (C-IBS), 15 alternating diarrhea and constipation IBS (M-IBS), and 100 healthy controls (mean±SD 37.2±11.4 years, median 36, range 20-64 years). 5-HTTLPR gene polymorphism was studied by polymerase chain reaction-based method. 5-HT levels were measured by enzyme-linked immunosorbent assay (ELISA). Orocecal transit time (OCTT) was measured by a non-invasive lactulose hydrogen breath test. OCTT was also compared with respect to 5-HTTLPR genotypes in different IBS phenotypes.

RESULTS

Serum serotonin levels were significantly higher in overall IBS patients (152±77 ng/mL, p<0.001), D-IBS (184±76 ng/mL, p<0.001), compared to healthy controls (129±56 ng/mL). There was no difference in 5-HT levels between C-IBS (124±53 ng/mL) and controls. In the case of M-IBS, 5-HT levels were (88±49 ng/mL p<0.05) significantly lower than that of controls. OCTT was significantly shorter in D-IBS patients (95±36 min) as compared to controls (112±41 min). In contrast, C-IBS showed significantly prolonged OCTT (136±54 min). There was a significant difference in OCTT between D-IBS and C-IBS patients (p<0.001). There was no significant association found between OCTT and 5-HTTLPR.

CONCLUSIONS

Serum serotonin concentrations were increased in D-IBS compared to controls and C-IBS. OCTT was shorter in D-IBS and delayed in C-IBS patients. There was no association of 5-HTLPR polymorphism with OCTT.