Indications, methodology, and interpretation of combined esophageal impedance-pH monitoring in children: ESPGHAN EURO-PIG standard protocol

Molecular diagnosis of eosinophilic esophagitis by gene expression profiling

BACKGROUND & AIMS

Gene expression profiling provides an opportunity for definitive diagnosis but has not yet been well applied to inflammatory diseases. Here we describe an approach for diagnosis of an emerging form of esophagitis, eosinophilic esophagitis (EoE), which is currently diagnosed by histology and clinical symptoms.

METHODS

We developed an EoE diagnostic panel (EDP) comprising a 96-gene quantitative polymerase chain reaction array and an associated dual-algorithm that uses cluster analysis and dimensionality reduction using a cohort of randomly selected esophageal biopsy samples from pediatric patients with EoE (n = 15) or without EoE (non-EoE controls, n = 14) and subsequently vetted the EDP using a separate cohort of 194 pediatric and adult patient samples derived from both fresh or formalin-fixed, paraffin-embedded tissue: active EoE (n = 91), control (non-EoE and EoE remission, n = 57), histologically ambiguous (n = 34), and reflux (n = 12) samples.

RESULTS

The EDP identified adult and pediatric patients with EoE with approximately 96% sensitivity and approximately 98% specificity, and distinguished patients with EoE in remission from controls, as well as identified patients exposed to swallowed glucorticoids. The EDP could be used with formalin-fixed, paraffin-embedded tissue RNA and distinguished patients with EoE from those with reflux esophagitis, identified by pH-impedance testing. Preliminary evidence showed that the EDP could identify patients likely to have disease relapse after treatment.

CONCLUSIONS

We developed a molecular diagnostic test (referred to as the EDP) that identifies patients with esophagitis in a fast, objective, and mechanistic manner, offering an opportunity to improve diagnosis and treatment, and a platform approach for other inflammatory diseases.

Gastroesophageal reflux in the 21st century

PURPOSE OF REVIEW

Gastroesophageal reflux (GER) remains a common, challenging problem for clinicians, with differentiation of normal development from disease a particular issue. This review updates clinicians on advances in diagnosis of GER, relationship to other problems, and current practice in management.

RECENT FINDINGS

Development and understanding of multichannel intraluminal impedance-pH monitoring has given insights into the relationship of GER to symptoms. Medical treatment has changed little. Avoidance of overmedicalizing normal development is the major issue for clinicians. Laparoscopic fundoplication is established as equivalent to open fundoplication. Newer endoscopic techniques have only limited use in children to date.

SUMMARY

Major changes in pediatric GER relate to understanding of physiology and relationship of GER to symptoms. The major challenge for clinicians involve differentiation of normal from abnormal GER, and applying the most relevant management.

Diagnosis of gastroesophageal reflux and anti-reflux procedures among Polish children with gastrostomies: a 10-year nationwide analysis

BACKGROUND/OBJECTIVES

To analyse the approach to diagnose gastroesophageal reflux (GER) and the qualification criteria for anti-reflux (AR) procedures in Polish children fed via gastrostomy between 2000 and 2010.

SUBJECTS/METHODS

An electronic questionnaire containing questions on the demographic and clinical data of patients with gastrostomies was distributed to six Polish centres of nutritional therapy. The portion pertaining to GER included data on clinical exponents, diagnostic procedures (pH-metry, pH-impedance, scintigraphy and upper gastrointestinal (GI) series) and AR.

RESULTS

In total, 348 children (M199/F149; age at gastrostomy 5.78±5.49 years) were included. Data on the diagnosis of GER and the AR criteria were available for 343 and 336 subjects, respectively. Percutaneous endoscopic gastrostomy was performed in 258/348 patients (74.1%), while surgery was performed in 80/348 patients (23%). The data from 10/348 (2.9%) cases were unavailable. At least one of the tests for GER was conducted in 177/343 (51.6%) of patients: pH-metry in 74/343 (21.6%), pH-impedance in 17/343 (5.0%), scintigraphy in 60/343 (17.5%) and upper GI series in 102/343 (29.7%). GER was reported in 114/343 cases (33.2%), and fundoplication was performed in 87 children (76.3% of patients with GER). The highest congruence between a positive test result and the decision to perform fundoplication was documented in cases of scintigraphy and upper GI series (P=0.00000 and P=0.00191, respectively). A significant increase in the prevalence of simultaneous gastrostomy and AR was observed over the decade analysed (r=0.8, P=0.009). This study revealed a centre-specific attitude towards the diagnosis of GER and the assessment of qualifications for fundoplication in Polish gastrostomy-fed children.

CONCLUSIONS

The unified diagnostic algorithm of GER and the universal qualification criteria for AR procedures need to be defined for gastrostomy-fed children.

The role of baseline impedance as a marker of mucosal integrity in children with gastro esophageal reflux disease

OBJECTIVES

Diagnosis of gastro esophageal reflux disease (GERD) in children is challenging. 24-h-pH-multichannel-intraluminal-impedance measurement (pH-MII) is the best diagnostic tool to display gastro esophageal reflux whereas esophageal endoscopy indicates mucosal lesions. The aim of this study was to compare esophageal endoscopy results with reflux parameters such as acid exposure time (reflux index RI), bolus exposure time (bolus index BI), baseline impedance level (BIL) detected by pH-MII in children with suspected GERD.

METHODS

Analysis of data from 285 children (38 infants) referred to our hospital with suspected GERD. Division into three 'reflux esophagitis' (RE)-stages depending on the severity of endoscopic and histological findings and comparison with reflux parameters in these stages. Further categorization into four groups based on the pH-MII-results.

RESULTS

Children with high-grade esophagitis had a significantly lower BIL; otherwise there was no significant association between elevated reflux parameters and esophagitis. Pathological pH-MII results (RI and BI) were associated with lower BIL in the distal impedance channel. The BIL was significantly lower in infants compared to children >1 year regardless of the RI or BI. The main difference between these groups regarding reflux parameters was a longer BI and a higher number of retrograde bolus movements.

CONCLUSION

Pathologic pH-MII results are not predictive for an erosive esophagitis and vice versa. Therefore, these two procedures cannot replace each other. A lower BIL is associated with esophagitis ≥ LA-grade B and may be caused by longer acid but also by longer bolus exposure and thus may be another useful parameter in GERD monitoring.

Challenges in the diagnosis of gastroesophageal reflux disease in infants and children

INTRODUCTION

The diagnosis of gastroesophageal reflux disease (GERD) is challenging. The wide variation in symptoms is a major reason for the controversies. Since the expression of GERD varies from nonerosive reflux disease over Barrett's esophagus to chronic respiratory disease, it is clear that not one investigation technique will provide an answer in all situations.

AREAS COVERED

Relevant literature published in PubMed and CINAHL and recent guidelines were collected and reviewed. Diagnostic tests were evaluated by the following criteria: ability to confirm a diagnosis, to exclude other diagnoses with similar presentation, to detect complications, to predict disease severity.

EXPERT OPINION

Multiple intraluminal impedance (MII) is extensively evaluated in recent years, but other new techniques and measurements were also developed, mainly to diagnose extra-esophageal symptoms. Although evidence for a "relation" between GER and extra-esophageal symptoms is demonstrated, the "causality" between both is not proven. MII measures in a reliable reproducible way non-acid or weakly acid reflux. However, as long as medical therapeutic options are limited to anti-acid medications, MII lacks therapeutic implications, and therefore clinical impact. Since investigations for GER are invasive or cause irradiation, normal ranges cannot be established. As a consequence, the "old" techniques remain the standard diagnostic tools: barium meal for anatomy, endoscopy for esophagitis, and pH monitoring to demonstrate a time relation between (acid) GER and symptoms. MII provides more information than pH monitoring, but is more expensive and has limited therapeutic impact as long as drugs are mainly "anti-acid."