Esophageal acid sensitivity and mucosal integrity in patients with functional heartburn

Roles of Cytokines in Pathological and Physiological Gastroesophageal Reflux Exposure

Background/Aims

Gastroesophageal reflux disease is frequently observed and has no definitive treatment. There are 2 main views on the pathogenesis of gastroesophageal reflux disease. The first is that epithelial damage starts from the mucosa by acidic-peptic damage and the inflammatory response of granulocytes. The other view is that T-lymphocytes attract chemoattractants from the basal layer to the mucosa, and granulocytes do not migrate until damage occurs. We aim to investigate the inflammatory processes occurring in the esophageal epithelium of the phenotypes at the molecular level. We also examined the effects of these changes on tissue integrity.

Methods

Patients with mild and severe erosive reflux, nonerosive reflux, reflux hypersensitivity, and functional heartburn were included. Inflammatory gene expressions (JAK/STAT Signaling and NFKappaB Primer Libraries), chemokine protein levels, and tissue integrity were examined in the esophageal biopsies.

Results

There was chronic inflammation in the severe erosion group, the acute response was also triggered. In the mild erosion group, these 2 processes worked together, but homeostatic cytokines were also secreted. In nonerosive groups, T-lymphocytes were more dominant. In addition, the inflammatory response was highly triggered in the reflux hypersensitivity and functional heartburn groups, and it was associated with physiological reflux exposure and sensitivity.

Conclusions

"Microinflammation" in physiological acid exposure groups indicates that even a mild trigger is sufficient for the initiation and progression of inflammatory activity. Additionally, the anti-inflammatory cytokines were highly increased. The results may have a potential role in the treatment of heartburn symptoms and healing of the mucosa.

Pathophysiology of gastro-oesophageal reflux disease: implications for diagnosis and management

Gastro-oesophageal reflux disease (GERD) is a common gastrointestinal disorder in which retrograde flow of gastric content into the oesophagus causes uncomfortable symptoms and/or complications. It has a multifactorial and partially understood pathophysiology. GERD starts in the stomach, where the refluxate material is produced. Following the trajectory of reflux, the failure of the antireflux barrier, primarily the lower oesophageal sphincter and the crural diaphragm, enables the refluxate to reach the oesophageal lumen, triggering oesophageal or extra-oesophageal symptoms. Reflux clearance mechanisms such as primary and secondary peristalsis and the arrival of bicarbonate-rich saliva are critical to prevent mucosal damage. Alterations of the oesophageal mucosal integrity, such as macroscopic oesophagitis or microscopic changes, determine the perception of symptoms. The intensity of the symptoms is affected by peripheral and central neural and psychological mechanisms. In this Review, we describe an updated understanding of the complex and multifactorial pathophysiology of GERD. It is now recognized that different GERD phenotypes have different degrees of reflux, severity of mucosal integrity damage and type, and severity of symptoms. These variations are probably due to the occurrence of a predominant pathophysiological mechanism in each patient. We also describe the main pathophysiological mechanisms of GERD and their implications for personalized diagnosis and management.

Refractory Gastroesophageal Reflux Disease: Diagnosis and Management

Gastroesophageal reflux disease (GERD) is common, with increasing worldwide disease prevalence and high economic burden. A significant number of patients will remain symptomatic following an empiric proton pump inhibitor (PPI) trial. Persistent symptoms despite PPI therapy are often mislabeled as refractory GERD. For patients with no prior GERD evidence (unproven GERD), testing is performed off antisecretory therapy to identify objective evidence of pathologic reflux using criteria outlined by the Lyon consensus. In proven GERD, differentiation between refractory symptoms (persisting symptoms despite optimized antisecretory therapy) and refractory GERD (abnormal reflux metrics on ambulatory pH impedance monitoring and/or persistent erosive esophagitis on endoscopy while on optimized PPI therapy) can direct subsequent management. While refractory symptoms may arise from esophageal hypersensitivity or functional heartburn, proven refractory GERD requires personalization of the management approach, tapping from an array of non-pharmacologic, pharmacologic, endoscopic, and surgical interventions. Proper diagnosis and management of refractory GERD is critical to mitigate undesirable long-term complications such as strictures, Barrett's esophagus, and esophageal adenocarcinoma. This review outlines the diagnostic workup of patients presenting with refractory GERD symptoms, describes the distinction between unproven and proven GERD, and provides a comprehensive review of the current treatment strategies available for the management of refractory GERD.

Esophageal Reflux Hypersensitivity: A Comprehensive Review

Reflux hypersensitivity (RH) is one of the phenotypes of gastroesophageal reflux disease. The latest Rome IV defines RH as a condition with typical reflux symptoms and positive reflux-symptom association despite normal acid exposure. Subsequently, the Lyon consensus proposed detailed cutoff values for the criteria on the basis of experts' consensus. Rome IV brought a clear-cut perspective into the pathophysiology of gastroesophageal reflux disease and the importance of esophageal hypersensitivity. This perspective can be supported by the fact that other functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia often overlap with RH. Although several possible pathophysiological mechanisms of esophageal hypersensitivity have been identified, there is still unmet medical needs in terms of treatment for this condition. This review summarizes the current knowledge regarding RH.

Esophageal secondary peristalsis following acid infusion and chemical clearance correlate with mucosal integrity and acid sensitivity in GERD patients

Background

Acid sensitivity can be altered in patients with gastroesophageal reflux disease (GERD). Secondary peristalsis helps clear gastro-esophageal refluxate and residual ingested food bolus.

Objectives

The aim of this study was to investigate the associations among acid sensitivity, esophageal mucosal integrity, chemical clearance, and secondary peristalsis before and after esophageal acid infusion.

Design

This was an investigator-initiated, prospective, cross-sectional study.

Methods

Adult reflux patients underwent high resolution manometry and 24 h impedance-pH monitoring off acid suppression to identify GERD phenotypes, including non-erosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH). Secondary peristalsis was assessed using five rapid 20 mL air injections into the esophagus before and after infusion of hydrochloric acid (0.1 N) into the mid-esophagus. Conventional acid infusion parameters recorded included lag time, intensity rating, and sensitivity score. Chemical clearance was evaluated using the post-reflux swallow-induced peristaltic wave (PSPW), and mucosal integrity was assessed by the mean nocturnal baseline impedance (MNBI) derived from impedance-pH monitoring.

Results

A total of 88 patients (age 21-64 years, 62.5% women) completed the study including 12 patients with NERD, 45 with RH, and 31 with FH. There was no significant difference in acid infusion parameters between patients with NERD, RH, and FH. Upon acid infusion, patients who exhibited successful secondary peristalsis had longer lag time, higher MNBI, and shorter bolus contact time than those without secondary peristalsis. Meanwhile, patients with intact PSPW demonstrated significantly higher intensity ratings in response to acid perfusion and higher MNBI than those with impaired PSPW. The lag time correlated positively with MNBI (r = 0.285; p = 0.007).

Conclusion

In conclusion, the protective effect of esophageal secondary peristalsis and chemical clearance on esophageal mucosal integrity was demonstrated. Concerning acid sensitivity, longer lag time in patients with intact secondary peristalsis may be attributed to better esophageal mucosal integrity, while stronger intensity ratings may have a greater tendency to induce PSPW and protect esophageal mucosal integrity.

Pump proton inhibitors display anti-tumour potential in glioma

OBJECTIVES

Glioma is one of the most aggressive brain tumours with poor overall survival despite advanced technology in surgical resection, chemotherapy and radiation. Progression and recurrence are the hinge causes of low survival. Our aim is to explain the concrete mechanism in the proliferation and progression of tumours based on tumour microenvironment (TME). The main purpose is to illustrate the mechanism of proton pump inhibitors (PPIs) in affecting acidity, hypoxia, oxidative stress, inflammatory response and autophagy based on the TME to induce apoptosis and enhance the sensitivity of chemoradiotherapy.

FINDINGS

TME is the main medium for tumour growth and progression. Acidity, hypoxia, inflammatory response, autophagy, angiogenesis and so on are the main causes of tumour progress. PPIs, as a common clinical drug to inhibit gastric acid secretion, have the advantages of fast onset, long action time and small adverse reactions. Nowadays, several kinds of literature highlight the potential of PPIs in inhibiting tumour progression. However, long-term use of PPIs alone also has obvious side effects. Therefore, till now, how to apply PPIs to promote the effect of radio-chemotherapy and find the concrete dose and concentration of combined use are novel challenges.

CONCLUSIONS

PPIs display the potential in enhancing the sensitivity of chemoradiotherapy to defend against glioma based on TME. In the clinic, it is also necessary to explore specific concentrations and dosages in synthetic applications.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

Prolonged Wireless pH Monitoring in Patients With Persistent Reflux Symptoms Despite Proton Pump Inhibitor Therapy

BACKGROUND & AIMS

Wireless pH monitoring measures esophageal acid exposure time (AET) for up to 96 hours. We evaluated competing methods of analysis of wireless pH data.

METHODS

Adult patients with persisting reflux symptoms despite acid suppression (n = 322, 48.5 ± 0.9 years, 61.7% women) from 2 tertiary centers were evaluated using symptom questionnaires and wireless pH monitoring off therapy, from November 2013 through September 2017; 30 healthy adults (control subjects; 26.9 ± 1.5 years; 60.0% women) were similarly evaluated. Concordance of daily AET (physiologic <4%, borderline 4%-6%, pathologic>6%) for 2 or more days constituted the predominant AET pattern. Each predominant pattern (physiologic, borderline, or pathologic) in relation to data from the first day, and total averaged AET, were compared with other interpretation paradigms (first 2 days, best day, or worst day) and with symptoms.

RESULTS

At least 2 days of AET data were available from 96.9% of patients, 3 days from 90.7%, and 4 days from 72.7%. A higher proportion of patients had a predominant pathologic pattern (31.4%) than control subjects (11.1%; P = .03). When 3 or more days of data were available, 90.4% of patients had a predominant AET pattern; when 2 days of data were available, 64.1% had a predominant AET pattern (P < .001). Day 1 AET was discordant with the predominant pattern in 22.4% of patients and was less strongly associated with the predominant pattern compared with 48 hour AET (P = .059) or total averaged AET (P = .02). Baseline symptom burden was higher in patients with a predominant pathologic pattern compared with a predominant physiologic pattern (P = .02).

CONCLUSIONS

The predominant AET pattern on prolonged wireless pH monitoring can identify patients at risk for reflux symptoms and provides gains over 24 hours and 48 hours recording, especially when results from the first 2 days are discordant or borderline.

Reflux Hypersensitivity: How to Approach Diagnosis and Management

PURPOSE OF REVIEW

This paper aims to review the definition and diagnostic criteria for reflux hypersensitivity and comment on the present and future management of this condition.

RECENT FINDINGS

In 2016, the Rome IV criteria redefined reflux hypersensitivity as characterized by typical reflux symptoms, absence of endoscopic mucosal disease, absence of pathologic gastroesophageal reflux, and positive symptom correlation between reflux and heartburn episodes. Though uncertain, TPRV1 receptors have been implicated in the pathophysiology of reflux hypersensitivity. Recent studies have shown neuromodulators like SSRIs, SNRIs, and TCAs may be the future of managing this condition. With the release of the Rome IV criteria and availability of continuous pH monitoring, the diagnosis of reflux hypersensitivity has become more streamlined. Though there is no definitive therapy for reflux hypersensitivity, several anti-secretory agents and neuromodulators have shown some efficacy in therapeutic trials. The lack of large-scale, randomized controlled trials, however, reinforces the need for further research into the pharmacotherapy of reflux hypersensitivity.

AGA Clinical Practice Update on Functional Heartburn: Expert Review

BEST PRACTICE ADVICE 1: A diagnosis of functional heartburn should be considered when retrosternal burning pain or discomfort persists despite maximal (double-dose) proton pump inhibitor (PPI) therapy taken appropriately before meals during a 3-month period. BEST PRACTICE ADVICE 2: A diagnosis of functional heartburn requires upper endoscopy with esophageal biopsies to rule out anatomic and mucosal abnormalities, esophageal high-resolution manometry to rule out major motor disorders, and pH monitoring off PPI therapy (or pH-impedance monitoring on therapy in patients with proven gastroesophageal reflux disease [GERD]), to document physiologic levels of esophageal acid exposure in the distal esophagus with absence of reflux-symptom association (ie, negative symptom index and symptom association probability). BEST PRACTICE ADVICE 3: Overlap of functional heartburn with proven GERD is diagnosed according to Rome IV criteria when heartburn persists despite maximal PPI therapy in patients with history of proven GERD (ie, positive pH study, erosive esophagitis, Barrett's esophagus, or esophageal ulcer), and pH impedance testing on PPI therapy demonstrates physiologic acid exposure without reflux-symptom association (ie, negative symptom index and symptom association probability). BEST PRACTICE ADVICE 4: PPIs have no therapeutic value in functional heartburn, the exception being proven GERD that overlaps with functional heartburn. BEST PRACTICE ADVICE 5: Neuromodulators, including tricyclic antidepressants, selective serotonin reuptake inhibitors, tegaserod, and histamine-2 receptor antagonists have benefit as either primary therapy in functional heartburn or as add-on therapy in functional heartburn that overlaps with proven GERD. BEST PRACTICE ADVICE 6: Based on available evidence, acupuncture and hypnotherapy may have benefit as monotherapy in functional heartburn, or as adjunctive therapy combined with other therapeutic modalities. BEST PRACTICE ADVICE 7: Based on available evidence, anti-reflux surgery and endoscopic GERD treatment modalities have no therapeutic benefit in functional heartburn and should not be recommended.

Pathophysiology, diagnosis, and pharmacological treatment of gastro-esophageal reflux disease

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic, relapsing disorder, whose knowledge has increased in last years thanks to the advent of new sophisticated techniques, such as 24-h impedance-pH monitoring and high-resolution manometry, for the study of esophageal functions.

AREAS COVERED

This review provides an overview of our advancements in understanding the complex pathophysiology, improving the diagnosis and defining the modern pharmacological therapeutic approach to GERD.

EXPERT OPINION

The growing clinical application of impedance-pH testing has allowed us to know the diversity of patients with non-erosive reflux disease (NERD), who nowadays represent about 70% of the whole population with reflux symptoms. We have realized that NERD has to be considered as an umbrella term covering various subgroups with different pathophysiologies. The development of new impedance metrics, in particular mean nocturnal baseline impedance, seems to be promising in the improvement of the diagnostic process of this disease. There are no particularly innovative features in the pharmacological therapy of GERD, unless the interest toward drugs is able to increase the defense properties of esophageal mucosa and/or its protection. These compounds can be of help in combination with proton pump inhibitors in NERD patients with partial response to antisecretory drugs alone.

In search of the grail: A race for acid suppression

Proton pump inhibitors are the reference standards for the treatment of acid-related diseases. Acid suppression in gastroesophageal reflux disease is associated with a high rate of mucosal cicatrization, but symptom response differs among endoscopic phenotypes. Extraesophageal manifestations have a good clinical response in patients that present with abnormal acid exposure (diagnostic test) in the esophagus. Proton pump inhibitors have shown their effectiveness for reducing symptom intensity in nighttime reflux and sleep disorders, improving quality of life and work productivity. That can sometimes be achieved through dose modifications by splitting or increasing the dose, or through galenic formulation. Proton pump inhibitors are not exempt from controversial aspects related to associated adverse events. Technological development is directed at improving proton pump inhibitor performance through increasing the half-life, maximum concentration, and area under the curve of the plasma concentrations through galenic formulation, as well as creating safer and more tolerable drugs. The present review is focused on the mechanisms of action, pharmacokinetic properties, and technological advances for increasing the pharmacologic performance of a proton pump inhibitor.

[Gastroesophageal Reflux Disease]

Gastroesophageal reflux disease (GERD) is a condition that develops when reflux of stomach contents causes troublesome symptoms and/or complications. The prevalence of GERD is increasing worldwide and in Asia-Pacific. The latest Korean guidelines for GERD were published in 2012, and several international guidelines and consensus statements for the management of GERD have also been recently published. Here, we review these guidelines and consensus statements in order to provide a better understanding of the diagnosis and treatment of GERD.

Evaluation of Esophageal Mucosal Integrity in Patients with Gastroesophageal Reflux Disease

BACKGROUND

Impaired esophageal mucosal integrity plays a role in causing symptoms of gastroesophageal reflux disease (GERD). Recently, the assessment of esophageal baseline impedance (BI) using the multichannel intraluminal impedance-pH (MII-pH) test was suggested as a surrogate technique for the study of esophageal mucosal integrity and was reported to be useful in distinguishing GERD from non-GERD. However, measuring BI requires a 24-h testing period, is complicated, and causes considerable patient discomfort.

SUMMARY

Recently, endoscopy-guided catheters that can measure mucosal impedance (MI) and mucosal admittance (MA), which is the inverse of impedance, were developed, and their usefulness in measuring MI and MA for the diagnosis of GERD has been reported. In these studies, esophageal MI values were significantly lower in patients with GERD than in those without GERD. In contrast, esophageal MA was significantly higher in patients with GERD than in those without. Furthermore, we reported that MA is inversely correlated with BI and correlated with acid exposure time. Key Messages: Endoscopy-guided real-time measurement of MI and MA may allow the estimation of mucosal integrity and may be a useful diagnostic tool for patients with GERD in a manner similar to 24-h MII-pH monitoring.

Reflux hypersensitivity

Reflux hypersensitivity (RH) is a condition characterized typically by heart burn, normal gastroscopy and esophageal biopsy, normal esophageal pH-impedance test, and a close correlation between heart burn and reflux events. Recently, Rome Ⅳ criteria suggests that reflux hypersensitivity is a new type of esophageal functional disease. It is very common in clinical practice and often coexists with functional heartburn. Diagnosis is based on heartburn symptoms, gastroscopy, esophageal biopsy, esophageal pH-impedance, and high resolution esophageal pressure. RH patients have normal acid exposure, and there is no dynamic disease in esophageal dynamic test. However, there are still some difficulties in the differential diagnosis of esophageal functional diseases. Symptom associated probability cannot reliably distinguish reflux hypersensitivity and functional heartburn. The pathogenesis of RH is not entirely clear. Recent studies have shown that esophageal sensitivity to acid and mucosal integrity can lead to RH. Because more than 90% of patients do not respond to proton pump inhibitors, esophageal neuromodulators, such as tricyclic antidepressants, are the main treatment, but the efficacy is uncertain. Surgery is a desirable method, but the indications should be strictly selected. In the future, it is important to strengthen the research of RH pathogenesis and seek new therapeutic targets.

SWALLOWING IN PATIENTS WITH LARYNGITIS

BACKGROUND

Dysphagia is described as a complaint in 32% of patients with laryngitis.

OBJECTIVE

The objective of this investigation was to evaluate oral and pharyngeal transit of patients with laryngitis, with the hypothesis that alteration in oral-pharyngeal bolus transit may be involved with dysphagia.

METHODS

Videofluoroscopic evaluation of the swallowing of liquid, paste and solid boluses was performed in 21 patients with laryngitis, 10 of them with dysphagia, and 21 normal volunteers of the same age and sex. Two swallows of 5 mL liquid bolus, two swallows of 5 mL paste bolus and two swallows of a solid bolus were evaluated in a random sequence. The liquid bolus was 100% liquid barium sulfate and the paste bolus was prepared with 50 mL of liquid barium and 4 g of food thickener (starch and maltodextrin). The solid bolus was a soft 2.2 g cookie coated with liquid barium. Durations of oral preparation, oral transit, pharyngeal transit, pharyngeal clearance, upper esophageal sphincter opening, hyoid movement and oral-pharyngeal transit were measured. All patients performed 24-hour distal esophageal pH evaluation previous to videofluoroscopy.

RESULTS

The evaluation of 24-hour distal esophageal pH showed abnormal gastroesophageal acid reflux in 10 patients. Patients showed longer oral preparation for paste bolus and a faster oral transit time for solid bolus than normal volunteers. Patients with laryngitis and dysphagia had longer preparation for paste and solid boluses, and a faster oral transit time with liquid, paste and solid boluses.

CONCLUSION

A longer oral preparation for paste and solid boluses and a faster transit through the mouth are associated with dysphagia in patients with laryngitis.

Pathophysiology of Gastroesophageal Reflux Disease

The pathogenesis of gastroesophageal reflux disease (GERD) is complex and involves changes in reflux exposure, epithelial resistance, and visceral sensitivity. The gastric refluxate is a noxious material that injures the esophagus and elicits symptoms. Esophageal exposure to gastric refluxate is the primary determinant of disease severity. This exposure arises via compromise of the anti-reflux barrier and reduced ability of the esophagus to clear and buffer the refluxate, leading to reflux disease. However, complications and symptoms also occur in the context of normal reflux burden, when there is either poor epithelial resistance or increased visceral sensitivity. Reflux therefore develops via alterations in the balance of aggressive and defensive forces.

Expert consensus document: Advances in the physiological assessment and diagnosis of GERD

GERD is a common condition worldwide. Key mechanisms of disease include abnormal oesophagogastric junction structure and function, and impaired oesophageal clearance. A therapeutic trial of acid-suppressive PPI therapy is often the initial management, with endoscopy performed in the setting of alarm symptoms and to exclude other conditions. If symptoms persist and endoscopy does not reveal evidence of GERD, oesophageal function tests are performed, including oesophageal manometry and ambulatory reflux monitoring. However, reflux episodes can be physiological, and some findings on endoscopy and manometry can be encountered in asymptomatic individuals without GERD symptoms. The diagnosis of GERD on the basis of functional oesophageal testing has been previously reported, but no updated expert recommendations on indications and the interpretation of oesophageal function testing in GERD has been made since the Porto consensus over a decade ago. In this Consensus Statement, we aim to describe modern oesophageal physiological tests and their analysis with an emphasis on establishing indications and consensus on interpretation parameters of oesophageal function testing for the evaluation of GERD in clinical practice. This document reflects the collective conclusions of the international GERD working group, incorporating existing data with expert consensus opinion.

Proton Pump Inhibitors in Gastroesophageal Reflux Disease: Friend or Foe

PURPOSE OF REVIEW

Proton pump inhibitor (PPI) use in gastroesophageal reflux disease (GERD) has been redefined, in light of recent advances highlighting GERD phenotypes that respond to PPIs, and fresh revelations of potential risks of long-term PPI therapy.

RECENT FINDINGS

Erosive esophagitis predicts excellent response to PPI therapy, but non-erosive reflux disease (NERD) with abnormal reflux parameters on ambulatory reflux monitoring also demonstrates a similar response. In contrast, response is suboptimal in the absence of abnormal reflux parameters. In this setting, if an alternate appropriate indication for PPI therapy does not coexist, risks may outweigh benefits of PPI therapy. Adverse events from long-term PPI therapy continue to be reported, most based on association rather than cause-and-effect. Appropriate indications need to be established before embarking on long-term PPI therapy. Future research will define true risks of long-term PPI therapy, and develop alternate management options for acid peptic diseases.

A review of pharmacotherapy for treating gastroesophageal reflux disease (GERD)

INTRODUCTION

Medical therapy of gastroesophageal reflux disease (GERD) is based on the use of proton pump inhibitors (PPIs) as first choice treatment. Despite their effectiveness, about 20-30% of patients report an inadequate response and alternative drugs are required. Areas covered: This review provides an overview of current pharmacotherapy for treating GERD by showing the results of PPIs, reflux inhibitors, antidepressants and mucosa protective medications. Expert opinion: Medical therapy of GERD does not definitely cure the disease, because even PPIs are not able to change the key factors responsible for it. However, they remain the mainstay of medical treatment, allowing us to alleviate symptoms, heal esophagitis and prevent complications in the majority of cases. Nevertheless, many patients do not respond, because acid does not play any pathogenetic role. Prokinetics and reflux inhibitors have the potential to control motor abnormalities, but the results of clinical trials are inconsistent. Antidepressant drugs are effective in specific subgroups of NERD patients with visceral hypersensitivity, but larger, controlled clinical studies are necessary. Protective drugs or medical devices have been recently adopted to reinforce mucosal resistance and preliminary trials have confirmed their efficacy either combined with or as add-on medication to PPIs in refractory patients.

The Role of Esophageal Hypersensitivity in Functional Heartburn

Functional heartburn (FH) is defined as a functional esophageal disorder characterized by symptoms of chronic heartburn with no apparent correlation to acid or nonacid reflux. In addition, its symptoms persist despite the lack of organic abnormalities or inflammation, esophageal motility disorders, or metabolic disorders. Although conditions presenting with esophageal symptoms without endoscopic abnormalities were previously categorized as nonerosive reflux disease, such conditions are now classified into 3 categories under Rome IV criteria: nonerosive reflux disease, reflux hypersensitivity, and FH. Although many aspects of FH remain unclear, its onset mechanism is considered to be strongly associated with peripheral or central sensitization, given the fact that its symptoms seem to be unrelated to gastroesophageal reflux. In addition, the cause of such hypersensitivity is an interesting topic in itself, and psychological factors, such as stress followed by increasing esophageal permeability are gaining attention as factors that can potentially influence this condition. There is a great unmet clinical need for therapeutic drugs that can be used to treat FH, and the development of novel drugs, diagnostic tests and biomarkers is eagerly awaited.

Does my patient still have reflux when ppi therapy does not work?

Gastroesophageal reflux disease (GERD) is a common condition around the world. The management of this disease is less than satisfying given complexity of patient presentation and suboptimal diagnostic testing when employed for those poorly responsive to acid suppressive therapy. In this mini review, we discuss some new strategies employed for patients with suspected GERD to better understand disease pathophysiology. We compare the strategies and outline a clinically relevant approach in this difficult group of patients.

The Role of Esophageal Hypersensitivity in Functional Esophageal Disorders

The Rome IV diagnostic criteria delineates 5 functional esophageal disorders which include functional chest pain, functional heartburn, reflux hypersensitivity, globus, and functional dysphagia. These are a heterogenous group of disorders which, despite having characteristic symptom profiles attributable to esophageal pathology, fail to demonstrate any structural, motility or inflammatory abnormalities on standard clinical testing. These disorders are associated with a marked reduction in patient quality of life, not least considerable healthcare resources. Furthermore, the pathophysiology of these disorders is incompletely understood. In this narrative review we provide the reader with an introductory primer to the structure and function of esophageal perception, including nociception that forms the basis of the putative mechanisms that may give rise to symptoms in functional esophageal disorders. We also discuss the provocative techniques and outcome measures by which esophageal hypersensitivity can be established.