Duodenal Pathology in Patients with Rumination Syndrome: Duodenal Eosinophilia and Increased Intraepithelial Lymphocytes

Duodenal Eosinophils and Mast Cells in Functional Dyspepsia: A Systematic Review and Meta-Analysis of Case-Control Studies

BACKGROUND & AIMS

This study explored the link between duodenal eosinophils and mast cells in patients with functional dyspepsia (FD).

METHODS

MEDLINE (PubMed) and Embase electronic databases were searched until June 2021 for case-control studies reporting duodenal eosinophils and mast cells in FD. Pooled standardized mean difference (SMD), odds ratio, and 95% CIs of duodenal eosinophils and mast cells in FD patients and controls were calculated, using a random-effects model.

RESULTS

Twenty-two case-control studies with 1108 FD patients and 893 controls were identified. Duodenal eosinophils (SMD, 1.29; 95% CI, 0.85-1.73; P = .0001) and mast cells (SMD, 2.11; 95% CI, 1.14-3.07; P = .0001) were increased in FD patients compared with controls. Substantial heterogeneity was found (I² = 93.61, P = .0001; and I² = 96.69, P = .0001, respectively) and visual inspection of funnel plots confirmed publication bias. Degranulation of duodenal eosinophils was significantly higher in FD patients compared with controls (odds ratio, 3.78; 95% CI, 6.76-4.48; P = .0001), without statistically significant heterogeneity. We conducted a sensitivity analysis for duodenal eosinophils, by including only high-quality studies, and the results remained unchanged (SMD, 1.73; 95% CI, 1.06-2.40; P = .0001), with substantial heterogeneity. Postinfectious FD patients had increased duodenal eosinophils compared with controls (SMD, 3.91; 95% CI, 1.32-6.51; P = .001) and FD patients without any history of infection (SMD, 1.42; 95% CI, 0.88-1.96; P = .001). Helicobacter pylori-negative FD patients had significantly higher duodenal eosinophils compared with controls (SMD, 3.98; 95% CI, 2.13-5.84; P = .0001), with substantial heterogeneity. No significant difference in duodenal eosinophils was seen according to FD subtypes.

CONCLUSIONS

This meta-analysis suggests a link between duodenal microinflammation and FD. However, the quality of evidence is very low, largely owing to the unexplained heterogeneity and serious risk of publication bias in all comparative analyses. Thus, causality remains uncertain and further studies are required.

Global Prevalence and Impact of Rumination Syndrome

BACKGROUND & AIMS

Rumination syndrome is a Disorder of Gut-Brain Interaction (DGBI) of unknown etiology. We aimed to assess its global prevalence and potential associations with other medical conditions.

METHODS

Data were collected via the Internet in 26 countries. Subjects were evenly distributed by country, sex, and age groups and were invited for a "health survey" using the Rome IV diagnostic questionnaire and a supplementary questionnaire addressing factors potentially associated with DGBI.

RESULTS

In all, 54,127 subjects completed the survey (51% male; mean age, 44.3 years). The overall prevalence of rumination syndrome was 3.1% (95% confidence interval [CI], 3.0-3.3%). It was highest in Brazil (5.5% CI, 4.5-6.5) and lowest in Singapore (1.7% CI, 1.1-2.2). The mean age of people with rumination syndrome was 44.5 years (standard deviation, 15.6) and it was more common in females (54.5% vs 45.5%). Factors independently associated with rumination syndrome were depression (odds ratio [OR], 1.46), anxiety (OR, 1.8), body mass index (OR, 1.04), and female sex (OR, 1.19). Subjects with multiple DGBI were at increased risk of having rumination syndrome, with the highest risk in subjects with 4 gastrointestinal regions with DGBI (OR, 15.9 compared with none). Quality of life (QoL) was lower in subjects with rumination syndrome compared with the rest of the cohort (PROMIS-10 score: physical QoL mean 12.9 vs 14.5; mental QoL mean 12.0 vs 13.6).

CONCLUSIONS

The prevalence of rumination syndrome is higher than reported in most previous population studies and is likely underdiagnosed in clinical practice. Awareness of rumination syndrome should be raised among clinicians to improve care for these patients.

Prevalence, symptoms and risk factor profile of rumination syndrome and functional dyspepsia: a population-based study

BACKGROUND

Rumination syndrome is a functional gastroduodenal disorder characterised by effortless regurgitation of recently ingested food. Emerging evidence reports duodenal eosinophilic inflammation in a subset, suggesting a shared pathophysiology with functional dyspepsia (FD).

AIM

To assess the clinical features of rumination syndrome and FD in a community-based study.

METHODS

We mailed a survey assessing gastrointestinal symptoms, diet and psychological symptoms to 9835 residents of Olmsted County, MN, USA in 2017-2018; diagnostic codes were obtained from linked clinical records. The two disorders were assessed as mutually exclusive in 'pure' forms with a separate overlap group, all compared to a control group not meeting criteria for either. Prevalence of associations, and univariate and independent associations with predictors were assessed by logistic regression.

RESULTS

Prevalence of rumination syndrome and FD were 5.8% and 7.1%, respectively; the overlap was 3.83-times more likely than expected by chance. Independent predictors for rumination (odds ratio (OR), 95% confidence interval (CI)) were female gender (1.79, 1.21-2.63), smoking (1.89, 1.28-2.78), gluten-free diet (1.58, 1.14-2.19), allergic rhinitis (1.45, 1.01-2.08) and depression (1.10, 1.05-1.16). FD was independently associated with female gender, depression, non-coeliac wheat sensitivity, migraine, irritable bowel syndrome and somatic symptoms. A similar reported efficacy (≥54%) of low fat or dairy-free diets was found with both disorders (P = 0.53 and P = 1.00, respectively). The strongest independent associations with overlapping FD and rumination syndrome were a history of rheumatoid arthritis (3.93, 1.28-12.06) and asthma (3.02, 1.44-6.34).

CONCLUSION

Rumination syndrome overlaps with FD with a shared risk factor profile, suggesting a common pathophysiology.

Duodenum at a crossroads: Key integrator of overlapping and psychological symptoms in functional dyspepsia?

The study of the interaction between gastrointestinal (GI) function and psychological features is a complex and developing field. The bidirectional communication between the gut and the brain or gut-brain axis is considered as a pivotal player in the pathogenesis of the highly prevalent functional GI disorders, including irritable bowel syndrome and functional dyspepsia (FD), which have been redefined as disorders of gut-brain interaction. However, the mechanisms through which changes in the gut alter brain functioning, feelings, and behavior remain unclear. Based on the presence of duodenal pathology in adult FD patients, Ronkainen et al. provide the first prospective evidence for duodenal eosinophils potentially driving anxiety. Also in this edition, associations between gastroduodenal pathology and rumination syndrome, which may coexist with FD, have now been confirmed in children by Friesen et al. Together these findings confirm not only the potential role of duodenal alterations in determining overlapping upper GI but also psychological symptoms, which result from bidirectional and complex interactions. In this review, we provide an overview of the recent advances in this field and highlight the novel contributions of the original studies of Ronkainen et al. and Friesen et al. to this topic.

Mucosal eosinophils, mast cells, and intraepithelial lymphocytes in youth with rumination syndrome

BACKGROUND

Rumination syndrome has been associated with increased duodenal eosinophils and intraepithelial lymphocytes in adults. The aims of the current study were to assess densities of antroduodenal eosinophils and mast cells and duodenal intraepithelial lymphocytes in youth with rumination syndrome and to compare cell densities in those with and without abdominal pain or early satiety.

METHODS

Twenty-eight youth fulfilling Rome IV criteria for rumination syndrome who had undergone endoscopy were identified and compared to 10 controls. Antral and duodenal biopsies were assessed to determine densities of eosinophils, mast cells, and intraepithelial lymphocytes. Cell densities were also compared between rumination patients with and without abdominal pain and those with and without early satiety.

KEY RESULTS

Antral mast cell (peak 18.5±6.5 vs. 12.5±2.7) and eosinophil (peak 9.6±5.2 vs. 4.9±2.1) densities were significantly greater in patients with rumination syndrome as compared to controls. Duodenal intraepithelial lymphocyte densities were also increased in rumination syndrome (18.9 ± 5.1 vs. 11.7 ± 1.5; p<.001). Associations were independent of the presence of abdominal pain or early satiety.

CONCLUSIONS AND INFERENCES

In conclusion, we found an increase in eosinophil and mast cell densities in the gastric antrum and an increase in intraepithelial lymphocytes in the duodenum in youth with rumination syndrome which was independent of the presence of abdominal pain or early satiety. These findings suggest a potential role for inflammation in the pathophysiology of rumination syndrome. Future studies should address whether treatment directed at these cells are beneficial in treating rumination syndrome.

Characterizing clinical features and location-specific gene expression profiles associated with pain burden in children with functional dyspepsia

BACKGROUND

In children with functional dyspepsia (FD), genes involved in pain modulation may be differentially expressed contributing to chronic pain.

METHODS

Children with suspected FD (cases) and known eosinophilic esophagitis (controls) undergoing esophagogastroduodenoscopy completed the Rome IV Diagnostic, Pain Burden and Frequency Severity-Duration questionnaires. Two antral and two duodenal biopsies were collected and relative fold differences in gene expression for 84 pain-associated genes compared to pain-free controls were calculated.

RESULTS

Sixty-six subjects with FD (postprandial distress syndrome = 34, epigastric pain syndrome = 7, both = 25; 65% female; mean age 13.7 years) and 13 pain-free controls (8% female; mean age 12.7) were studied. There were no significant differences in antral and duodenal eosinophilic counts or distribution between the pain and pain-free groups. Pain severity and burden did not differ significantly between FD subgroups and neither measure significantly correlated with eosinophil counts in the antrum or duodenum. Analysis of 47 antral and 39 duodenal biospecimens revealed 5 candidate genes significantly associated with pain burden: antral EDN1, PTGES3 and duodenal HTR1A, P2Y1, SCN3A (p < 0.01). Subsequent stringent statistical analysis comparing those with significant pain versus no pain revealed antral PTGES3 and duodenal SCN3A were the highest priority candidate genes (p < 0.001).

CONCLUSIONS

Pain burden in pediatric FD may be linked to antral EDN1, PTGES3 and duodenal HTR1A, P2Y1, SCN3A differential expression. These genes are known to be involved in pain conduction, modulation, and neurotransmission, suggesting potential therapeutic targets for managing pain in FD.

Rumination Syndrome in Children and Adolescents: A Mini Review

Introduction: Rumination syndrome involves recurrent regurgitation of food and is believed to be underdiagnosed with patients experiencing long delays in diagnosis. It can be associated with significant social consequences, high rates of school absenteeism, and medical complications such as weight loss. The primary aims of the current review are to assess the literature regarding prevalence, pathophysiology, and treatment outcomes with a focus on neurotypical children and adolescents. Results: Population studies in children/adolescents, 5 years of age or older, range from 0 to 5.1%. There are fewer studies in clinical settings, but the prevalence appears to be higher in patients with other gastrointestinal symptoms, particularly chronic vomiting. While physiologic changes that occur during a rumination episode are well-described, the underlying cause is less well-defined. In general, rumination appears to have similarities to other functional gastrointestinal disorders including dysmotility, possibly inflammation, and an interaction with psychologic function. While diaphragmatic breathing is considered the mainstay of treatment, pediatric data demonstrating efficacy is lacking, especially as an isolated treatment. Conclusion: Pediatric rumination syndrome remains greatly understudied, particularly regarding treatment. There is a need to better define prevalence in both the primary care and subspecialty clinical settings, especially in patients presenting with vomiting or apparent gastroesophageal reflux. There is a need to determine whether treatment of co-morbid conditions results in improvement of rumination. Diaphragmatic breathing needs to be studied and compared to other competing responses.

Rumination syndrome. A review article

Rumination syndrome is a functional gastrointestinal disorder characterized by effortless postprandial regurgitation of ingested food into the mouth. An unperceived postprandial contraction of the abdominal wall could be a key mechanism. In those patients, retrograde flow of the ingested gastric content into the mouth is produced due to a simultaneous combination of elevated intra-abdominal pressure and negative intrathoracic pressure. The estimated prevalence is around 2% in the general adult population. The main clinical characteristics include: a) early postprandial regurgitation, b) the effortlessly regurgitated material is similar to the ingested food, c) the regurgitated material is spit out or swallowed again. The clinical diagnosis of rumination syndrome relies on the clinical criteria. High resolution esophageal manometry, ideally including impedance monitoring, can be an important adjunct for making the clinical diagnosis. Its management is based on instruction as to the nature of the pathology, education in postprandial diaphragmatic breathing, and the assessment of possible psychiatric comorbidity. Baclofen use is reserved for second-line treatment in patients with refractory symptoms.

Optimal management of severe symptomatic gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disorder, and empirical proton pump inhibitor (PPI) treatment is often the first step of management; however, up to 40% of patients remain symptomatic despite PPI treatment. Refractory reflux refers to continued symptoms despite an adequate trial of PPI, and management remains challenging. The differential diagnosis is important; other oesophageal (e.g. eosinophilic oesophagitis) and gastroduodenal disorders (e.g. functional dyspepsia) should be ruled out, as this changes management. A combination of clinical assessment, endoscopic evaluation and in selected cases oesophageal function testing can help characterize patients with refractory reflux symptoms into oesophageal phenotypes so appropriate therapy can be more optimally targeted. Medical options then may include adding a H2 receptor antagonist, alginates, baclofen or antidepressant therapy, and there is emerging evidence for bile acid sequestrants and diaphragmatic breathing. The demonstration of a temporal association of symptoms with reflux events on pH-impedance testing (reflux hypersensitivity) serves to focus the management on modulating oesophageal perception and reducing the reflux burden, or identifies those with no obvious pathophysiologic abnormalities (functional heartburn). Anti-reflux surgery based on randomized controlled trial evidence has a role in reflux hypersensitivity or continued pathological acid reflux despite PPI in carefully considered, fully worked up cases that have failed medical therapy; approximately two of three cases will respond but there is a small risk of complications. In patients with persistent volume reflux despite medical therapy, given the lack of alternatives, anti-reflux surgery is a consideration. Promising newer approaches include endoscopic techniques. This review aims to summarize current diagnostic approaches and critically evaluates the evidence for the efficacy of available treatments.

Ileocolonic Histopathological and Microbial Alterations in the Irritable Bowel Syndrome: A Nested Community Case-Control Study

INTRODUCTION

Histopathological alterations in the ileum and colon in irritable bowel syndrome (IBS) are controversial, and normal values are poorly established. We hypothesized that changes in mucosal immune cells characterize IBS and key changes in immune composition are associated with the mucosa-associated microbiota (MaM).

METHODS

A nested case-control study (48 IBS and 106 controls included) from 745 colonoscopy participants in a random population sample. Intraepithelial lymphocytes (IELs)/100 enterocytes and eosinophils/5 nonoverlapping high-power fields counted; mast cells identified by immunocytochemistry (CD117)/5 high-power fields. Paneth cells quantified per 5 crypts. 16S rRNA gene amplicon sequencing performed on available sigmoid MaM, n = 55 and fecal microbiota, n = 20. Microbiota profiles compared between samples with high and low IEL counts.

RESULTS

IBS had increased IELs in the terminal ileum (relative risk ratio = 1.70, 95% confidence interval 1.08-2.76, P = 0.022 adjusted for age, sex, and smoking). Cecal IELs were increased in IBS-diarrhea (relative risk ratio = 2.03, 95% confidence interval 1.13-3.63, P = 0.017). No difference was observed in alpha diversity of MaM or fecal microbiota based on IEL count. There was no difference in beta diversity of the MaM according to IEL count in the terminal ileal (TI) (P = 0.079). High TI IEL counts associated with a significant expansion of the genus Blautia (P = 0.024) and unclassified Clostridiales (P = 0.036) in colon MaM.

DISCUSSION

A modest but significant increase in IELs was observed in IBS vs. controls in a population-based setting. Subtle TI and cecal inflammation may play a pathogenic role in IBS but needs confirmation. Modest but discernible differences in the colonic MaM were seen according to TI IEL count but not IBS status.

Rumination syndrome: when to suspect and how to treat

PURPOSE OF REVIEW

Rumination syndrome is a gastrointestinal disorder characterized by effortless regurgitation of recently ingested food. The disorder is rare, but likely under-recognized and leads to impaired quality of life among those affected. This review discusses recent studies which examined the pathophysiology, diagnoses and therapy of rumination syndrome.

RECENT FINDINGS

The pathogenesis of rumination syndrome remains incompletely understood. Therapeutic options, which appear effective, include behavioral therapy with diaphragmatic breathing and pharmacotherapy with baclofen. A randomized trial of behavioral therapy, biofeedback therapy led to a 74% + /- 6% reduction in rumination activity (from 29  + /- 6 before to 7 + /- 2 daily events after intervention) vs. 1% + /- 14% during sham (from 21 + /- 2 before to 21 + /- 4 daily events after intervention) (P = .001). A recent randomized trial of baclofen at a dose of 10 mg three times daily led to symptomatic improvement in 63% of patients with rumination syndrome.

SUMMARY

This review summarizes a clinical approach to diagnosing and treating rumination syndrome. Behavioral therapy consisting of diaphragmatic breathing, with or without biofeedback, remains the most effective treatment strategy for patients with rumination syndrome.