Introduction

Chronic Intestinal Pseudo-Obstruction (CIPO) is a severe dysmotility disorder, which manifests with recurrent sub-obstructive episodes without mechanical causes of gut occlusion. We previously identified a novel missense mutation (p.Ala622Thr) in RAD21 in a consanguineous family with multiple patients affected by CIPO¹. We now developed a conditional knock-in (Rad21KI^A626T) mouse to express the RAD21 mutation in the enteric nervous system (ENS).

Aims & Methods

We aimed to characterize in vivo and ex vivo the effects of the CIPO-causing RAD21 variant on gut motility, ENS function and structure in a recently generated conditional knock-in mouse. We developed a genetically re-constructed rad21 conditional knock-in (Wnt1-Cre x rad21fl/fl) mouse carrying the p.A626T missense variant (position p.A626 in mouse is homologue of human amino acid p.A622). The mutation p.A626T was introduced in rad21 to be expressed in response to Cre-driven recombination of the floxed alleles, driving its expression into subsets of ENS neurons in response to Wnt1 expression at any developmental points. Homozygous Rad21KI^A626Tvs. wild-type (WT) mice were compared. Intestinal transit time was evaluated with carmine red dye gavage. Recordings of isometric tension using organ-bath techniques was performed to evaluate myogenic and nerve-mediated motility in the large intestine. Immunolabelling was performed in whole-mount myenteric plexus with antibodies against the pan-neuronal marker HuC/D, choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS) and synaptophysin (Syn) in small and large intestine.

Results

We observed an increased intestinal transit time in Rad21KI^A626Tvs. WT (260.50±20.85 min vs. 190.00±12.25 min; P=0.0071). Mean motility index and mean active force, key indexes of myoelectric activity, showed a significant reduction in Rad21KI^A626Tvs. WT mice (3.00±0.23 vs. 5.26±0.58; P<0.005; 0.45±0.05 vs. 0.94±0.10; P=0.0005, respectively). In the small and large intestine of Rad21KI^A626Tmice, HuC/D/ChAT-positive myenteric neurons/field were significantly less vs. WT (18.90 ± 1.40 vs. 32.40 ±2.00; P=0.0152; 19.80±2.10 vs. 32.10±3.80; P=0.0260, respectively). The synaptic vesicle analysis showed a significant decrease of Syn in the Rad21KI^A626T small and large intestine vs. WT (22.12 ± 1.65 vs. 34.11 ± 2.07, P=0.0126 and 22.53 ± 3.31 vs. 36.54 ± 3.54, P=0.0115, respectively).

Conclusion

Rad21KI^A626T mice exhibited a significantly delayed intestinal transit, with reduced motility and a decreased number of ChAT-positive myenteric neurons along with a lower synaptic density. These findings indicate that this conditional k.i. mouse can be considered as a novel model for the study of CIPO.

References

1. Bonora et al., Mutations in RAD21 disrupt regulation of APOB in patients with chronic intestinal pseudo-obstruction. Gastroenterology. 2015;148:771-782.e11.

Introduction

Celiac disease (CD) is an immune-mediated enteropathy triggered by gluten ingestion in genetically predisposed individuals, characterized by small intestinal inflammation and villous atrophy. Microbial agents such as Helicobacter pylori (H. pylori) may influence autoimmune disorders, including CD, through immune modulation. However, the relationship remains controversial.This study aimed to assess the association between CD and H. pylori infection by comparing the prevalence of H. pylori in patients with and without CD.

Aims & Methods

We conducted a retrospective study from January 2019 to December 2024. Two groups were analyzed: patients with biopsy-confirmed CD and controls without CD who underwent upper endoscopy for dyspeptic or non-specific gastrointestinal symptoms. Exclusion criteria included prior H. pylori eradication, recent use of PPIs, antibiotics, or bismuth compounds, other autoimmune disorders, and incomplete data.

Results

A total of 231 patients were included: 103 with CD (19.4% male, mean age 28.8 ± 12.6 years) and 128 controls (28.1% male, mean age 33.9 ± 11.9 years).
No significant differences were observed in age (p = 0.73) or sex distribution (p = 0.167) between groups.
H. pylori was detected in 67% of CD patients and 50% of controls, with a significantly higher prevalence in the CD group (p = 0.014).

Conclusion

Contrary to some previous reports suggesting a protective effect, this study found a significantly higher prevalence of H. pylori in patients with CD compared to controls.
These findings highlight the need for further investigations into the potential impact of H. pylori on the clinical presentation and management of celiac disease.

Introduction

Cholecystectomy is recommended for patients with acute biliary pancreatitis to prevent recurrence and other biliary complications. However, some patients, due to advanced age and comorbidities, are unfit for surgery. The role of endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy (ES) in these cases is not well established^1,2.

Aims & Methods

We aimed to evaluate whether ES reduces the risk of recurrent biliary pancreatitis (RBP) in patients unfit for cholecystectomy.
A unicentric retrospective review was conducted including all patients admitted for a first episode of acute biliary pancreatitis between January 2016 and November 2023 at a non-tertiary hospital, who were deemed unfit for cholecystectomy by either surgical or anesthetic teams. Patients with concurrent acute cholangitis at admission or during hospitalization, as well as those with prior cholecystectomy or ES, were excluded. Time-to-event analysis was performed using Kaplan-Meier survival curves.

Results

A total of 169 patients were included, with a mean age of 79.07 ± 8.25 years, and 65% were female. The mean Charlson Comorbidity Index was 5.11 ± 2.09. Most cases (94%) presented as mild or moderately severe pancreatitis. The mean follow-up period was 3.80 ± 1.95 years.
During the index admission, 37% (n=62) underwent ERCP with ES.
Recurrent biliary pancreatitis (RBP) occurred in 35 patients (21%), 97% of whom had not undergone ES. Only one patient in the ES group was readmitted for a new episode of pancreatitis (p<0.001, OR 0.035; 95% CI 0.005–0.265). The mean time to recurrence was 2.67 ± 7.78 months. Kaplan-Meier survival analysis demonstrated a significantly lower cumulative incidence of RBP in the ES group (log-rank p<0.001).
Endoscopic sphincterotomy did not significantly reduce other biliary events, including choledocholithiasis, acute cholangitis, and acute cholecystitis (all p>0.05). There was no statistically significant difference in overall mortality between the two groups (p=0.585).

Conclusion

Our findings suggest that ERCP with ES may effectively reduce the recurrence of gallstone pancreatitis in elderly patients with high surgical-anesthetic risk due to comorbidities. Further studies are needed to refine the selection criteria for these patients.

References

1 - Hwang SS, Li BH, Haigh PI. Gallstone pancreatitis without cholecystectomy. JAMA Surg. 2013 Sep;148(9):867-72.
2 - McAlister, V., Davenport, E., & Renouf, E. (2007). Cholecystectomy deferral in patients with endoscopic sphincterotomy. Cochrane Database of Systematic Reviews.

Introduction

Parkinson’s disease (PD) is a neurodegenerative disorder. Prior to the manifestation of the motor-symptom of bradykinesia, non-motor symptoms like constipation frequently occur in the prodromal stadium (pPD). Therefore, involvement of the gastrointestinal (GI) tract, especially alterations of the enteric nervous system (ENS), in the pathogenesis can be assumed. Studying the GI tract with its ENS became the focus of research due to its good accessibility. Probe-based confocal laser-endomicroscopy (pCLE) allows to visualize structures of the GI tract in 1000-fold magnification. Therefore, pCLE seems to be a promising approach in the visualization of the ENS in vivo.

Aims & Methods

Aim: Visualization of the ENS by pCLE to create an imaging biomarker for the severity of PD in vivo compared to healthy controls (HC).
Patients with manifest PD and HC undergoing screening colonoscopy were included in this prospective trial. After removal of the mucosal surface with large biopsy forceps, label-free in vivo pCLE (Coloflex, Cellvizio) was performed in the rectum to visualize the ENS in vivo. Observation of neuronal structures in the submucosal plexus was performed with the help of tissue specific autofluorescence (AF). The specific AF was quantified per field of view and assigned to corresponding neuronal structures - small nerve fibre strands, big nerve fibre strands (NFS) and nerve cell bodies (NCB) (impressing as “cotton-balls”). To reliably compare our findings, we performed a direct comparison between conventional immunohistology and ex vivo pCLE. The results of in vivo pCLE were finally correlated to the severity of clinical symptoms.

Results

28 patients with PD and 15 healthy controls were included in this prospective trial. Age and sex distribution did not exhibit statistical differences. In PD we could observe a higher tissue AF in images with small NFS (AF_PD=2848±1889; AF_HC=972±811; p=0.007), with big NFS (AF_PD=22217±1940; AF_HC=687±702; p=0.008) and a larger diameter of nerve cell bodies (“cotton balls”) in PD patients (Diameter_PD=8.2±1.9µm; Diameter_HC=6.7±0.6µm; p=0.04). The total number of small nerves and ganglions in both groups did not differ (ns). Of note, a strong positive correlation of age and increasing accumulation of AF was observed in both groups (p=0.02). Specific morphological distinctions were not noticed. ENS phenotypes showed a strong correlation with clinical manifestation of symptoms (p=0.002).

Conclusion

Label-free pCLE allows reliable in vivo imaging of the ENS in vivo and differentiate between NFS and NCB. Patients with PD have increased AF of submucosal nerve components in comparison to HC. Furthermore, the severity of PD symptoms significantly correlates with increasing AF of ENS in the rectum and can therefore be used as an imaging biomarker for PD that potentially allows for diagnosis of pPD.