The Role of Salivary Pepsin in the Diagnosis of Gastroesophageal Reflux Disease (GERD) Evaluated Using High-Resolution Manometry and 24-Hour Multichannel Intraluminal Impedance-pH Monitoring

The association between salivary pepsin and gastroesophageal reflux disease: A meta-analysis

BACKGROUND AND PURPOSE

The definitive diagnosis of gastroesophageal reflux disease (GERD) often requires invasive investigations like upper gastrointestinal endoscopy or reflux monitoring. We aimed to explore the relationship between salivary pepsin and GERD and its value as a non-invasive diagnostic tool.

METHODS

Databases (PubMed, Web of Science, Cochran Library, and EMBASE) were searched from their inception to January 22, 2024 to explore the correlation of salivary pepsin with GERD. The meta-analysis data retrieved were summarized, including the salivary pepsin concentration, sensitivity of diagnosis (SEN), specificity of diagnosis (SPE), negative likelihood ratio, positive likelihood ratio, diagnostic odds ratio, and receiver operating characteristic (ROC) curve.

RESULTS

The meta-analysis comparing salivary pepsin concentration in two groups (proven GERD and non-GERD) with 18 studies revealed that the proven GERD group had higher salivary pepsin concentration than the non-GERD group (SMD = 1.74 [95% CI 1.14-2.34]). The meta-analysis of salivary pepsin diagnostic value for proven GERD incorporated 23 studies. The results showed pooled SEN (0.73 [95% CI 0.66-0.80]), SPE (0.72 [95% CI 0.65-0.78]), positive likelihood ratio (2.61 [95% CI 2.02-3.39]), negative likelihood ratio (0.37 [95% CI 0.28-0.50]), diagnostic odds ratio (7.03 [95% CI 4.24-11.66]) and area under the SROC curve (0.79 [95% CI 0.75-0.82]).

CONCLUSION

GERD patients presented a higher salivary pepsin concentration. Salivary pepsin is both sensitive and specific in identifying GERD, making it a promising non-invasive marker for diagnosis.

Advances in laryngopharyngeal reflux: Etiology, diagnosis, and management

Laryngopharyngeal reflux (LPR) manifests as a variety of nonspecific upper aerodigestive tract symptoms. Rather than a single disorder, LPR may be conceived of as a spectrum of subtypes with varying clinical presentations. LPR signs and symptoms arise from the direct and/or indirect effects of refluxate, physical and molecular injury of the mucosa, and neurologic responses to esophageal events. Specific constituents of refluxate exert distinct mucosal responses and immediate or delayed effects resulting in transient or persistent symptoms and/or laryngeal hypersensitivity. While the complex etiology of LPR presents challenges to its diagnosis and management, tools that aid the identification of LPR subtypes can provide insight into treatment decision-making. Hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring provides detailed analysis of reflux events, enabling the development of individualized treatment plans, yet cost and availability limit its widespread use. Alginates offer temporary symptom relief and antireflux surgery may provide benefit when symptoms are recalcitrant to other approaches. Pepsin inhibitors hold promise as a medical therapy when surgery is not an option. Laryngeal hypersensitivity should be considered as part of a comprehensive therapeutic approach. Promising medical and scientific research continues to yield new insights into the complex etiology of LPR and novel strategies for its diagnosis and management.

Review article: Diagnosis and management of laryngopharyngeal reflux

BACKGROUND

Laryngopharyngeal reflux has classically referred to gastroesophageal reflux leading to chronic laryngeal symptoms such as throat clearing, dysphonia, cough, globus sensation, sore throat or mucus in the throat. Current lack of clear diagnostic criteria significantly impairs practitioners' ability to identify and manage laryngopharyngeal reflux.

AIMS

To discuss current evidence-based diagnostic and management strategies in patients with laryngopharyngeal reflux.

METHODS

We selected studies primarily based on current guidelines for gastroesophageal reflux disease and laryngopharyngeal reflux, and through PubMed searches.

RESULTS

We assess the current diagnostic modalities that can be used to determine if laryngopharyngeal reflux is the cause of a patient's laryngeal symptoms, as well as review some of the common treatments that have been used for these patients. In addition, we note that the lack of a clear diagnostic gold-standard, as well as specific diagnostic criteria, significantly limit clinicians' ability to determine adequate therapies for these patients. Finally, we identify areas of future research that are needed to better manage these patients.

CONCLUSIONS

Patients with chronic laryngeal symptoms are complex due to the heterogenous nature of symptom pathology, inconsistent definitions and variable response to therapies. Further outcomes data are critically needed to help elucidate ideal diagnostic workup and therapeutic management for these challenging patients.

Latin American consensus on diagnosis of gastroesophageal reflux disease

BACKGROUND

Diagnosing gastroesophageal reflux disease (GERD) can be challenging given varying symptom presentations, and complex multifactorial pathophysiology. The gold standard for GERD diagnosis is esophageal acid exposure time (AET) measured by pH-metry. A variety of additional diagnostic tools are available. The goal of this consensus was to assess the individual merits of GERD diagnostic tools based on current evidence, and provide consensus recommendations following discussion and voting by experts.

METHODS

This consensus was developed by 15 experts from nine countries, based on a systematic search of the literature, using GRADE (grading of recommendations, assessment, development and evaluation) methodology to assess the quality and strength of the evidence, and provide recommendations regarding the diagnostic utility of different GERD diagnosis tools, using AET as the reference standard.

KEY RESULTS

A proton pump inhibitor (PPI) trial is appropriate for patients with heartburn and no alarm symptoms, but nor for patients with regurgitation, chest pain, or extraesophageal presentations. Severe erosive esophagitis and abnormal reflux monitoring off PPI are clearly indicative of GERD. Esophagram, esophageal biopsies, laryngoscopy, and pharyngeal pH monitoring are not recommended to diagnose GERD. Patients with PPI-refractory symptoms and normal endoscopy require reflux monitoring by pH or pH-impedance to confirm or exclude GERD, and identify treatment failure mechanisms. GERD confounders need to be considered in some patients, pH-impedance can identify supragrastric belching, impedance-manometry can diagnose rumination.

CONCLUSIONS

Erosive esophagitis on endoscopy and abnormal pH or pH-impedance monitoring are the most appropriate methods to establish a diagnosis of GERD. Other tools may add useful complementary information.

Threshold level of Peptest in diagnosing gastroesophageal reflux disease with extraesophageal symptoms: Evidence from Vietnam

Background and Aim

We aimed to evaluate the application of Peptest, a novel technique to detect pepsin in the saliva, and identify its threshold level for the diagnosis of gastroesophageal reflux disease (GERD) with extraesophageal symptoms.

Methods

A cross-sectional study was conducted in two groups: patients with extraesophageal GERD symptoms (symptomatic group divided into GERD and non-GERD groups according to 24-h esophageal pH-impedance monitoring [pH-I] results) and healthy controls. For the symptomatic group, endoscopy, pH 24 h, high-resolution manometry (HRM), and salivary Peptest were performed. For the healthy control group, only Peptest was done. The accuracy of Peptest was compared with that of pH-I by the Lyon consensus criteria.

Results

Chronic laryngitis was the most frequent extraesophageal symptom. On saliva testing, the GERD group had a higher prevalence of positive samples and pepsin concentration than the control group. Between GERD and non-GERD groups, the optimal threshold level was 31.2 ng/mL, with a sensitivity of 86.7% and specificity of 27.5%. The optimal threshold level was 31.4 ng/mL to differentiate GERD from healthy controls, with a sensitivity of 86.7% and specificity of 66.0%. Age, number of total refluxes, DeMeester score, post-reflux swallow-induced peristaltic wave (PSPW) index, and mean nocturnal baseline impedence (MNBI) were associated with pepsin concentration. Regarding HRM metrics, there was no significant difference of pepsin concentration between low/normal upper esophageal sphincter (UES) resting pressure, low/normal lower esophageal sphincter (LES) resting pressure, low/normal 4-s integrated relaxation pressure (IRP4s), and hypomotility/normal motility.

Conclusion

Patients with extraesophageal symptoms had a higher prevalence of positive Peptest. The optimum threshold level of 31.4 ng/mL had high sensitivity and moderate specificity to differentiate between patients with GERD and healthy controls.

Diagnostic thresholds and optimal collection protocol of salivary pepsin for gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is primarily diagnosed based on symptoms and response to a proton-pump inhibitor (PPI) trial. Gold standard testing requires an invasive endoscopic procedure, often with ambulatory pH monitoring. Salivary pepsin is a potential noninvasive modality for GERD diagnosis. This study aimed to assess diagnostic performance of salivary pepsin thresholds for GERD and determine optimal collection protocol of saliva in an external validation cohort. Over 10 months, adults with symptoms of GERD undergoing esophagogastroduodenoscopy with wireless pH-monitoring off PPI were enrolled. Saliva was self-collected by participants over 4 days across three different time points: fasting ante meridiem (AM), post-prandial, and bedtime (PM). Pepsin levels were calculated via Peptest. Pepsin variability and agreement were determined using linear mixed effects models and intraclass correlation. Validation of diagnostic threshold and performance characteristics were evaluated by receiver-operator curve analysis. Twenty participants enrolled in the study; 50% with physiologic acid exposure (acid exposure time < 4% no GERD) and 50% with elevated acid exposure (GERD). Mean pepsin concentrations were significantly lower in the AM (22.6 ± 25.2 ng/mL) compared to post-prandial (44.5 ± 36.7 ng/mL) and PM (55.4 ± 47.0 ng/mL). Agreement between pepsin concentrations across 3 days was substantial for AM samples (kappa 0.61), with lower agreement for post-prandial and PM samples. A single AM pepsin concentration of 25 ng/mL was 67% accurate for GERD with 56% sensitivity and 78% specificity. This validation study highlights fair accuracy and performance characteristics of a single fasting AM salivary pepsin concentration for the diagnosis of GERD.

Salivary biomarkers and esophageal disorders

Saliva is a complex physiologic fluid that contains an abundance of biological analytes, or biomarkers. Recent research has shown that these biomarkers may be able to convey the physiologic health of a person. Work has been done linking derangements in these salivary biomarkers to a wide variety of pathologic disorders ranging from oncologic diseases to atopic conditions. The specific area of interest for this review paper is esophageal disorders. Particularly because the diagnosis and management of esophageal disorders often includes invasive testing such as esophagogastroduodenoscopy, prolonged pH monitoring, and biopsy. The aim of this review will be to explore salivary biomarkers (pepsin, bile, epidermal growth factor, and micro-RNA) that are being studied as they relate specifically to esophageal disorders. Finally, it will explore the benefits of salivary testing and identify areas of possible future research.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Gastroesophageal reflux disease and salivary pepsin in patients with heterotopic gastric mucosa in the upper esophagus

BACKGROUND

Heterotopic gastric mucosa in the upper esophagus (HGMUE) is reported to be related to gastroesophageal reflux disease (GERD). This study investigated the prevalence of GERD and the use of salivary pepsin to diagnose gastroesophageal reflux, especially proximal reflux, in HGMUE patients.

METHODS

One hundred and fifty-three HGMUE patients and 50 healthy volunteers were studied. All subjects took a reflux symptom index questionnaire (RSI); underwent endoscopy, barium esophagogram, high-resolution manometry (HRM), and 24-hour multichannel intraluminal impedance-pH-metry (MII-pH); and salivary pepsin test.

RESULTS

Ninety-five (62.1%) HGMUE patients but no control subjects were diagnosed with GERD. The salivary pepsin concentration, RSI score, DeMeester score, acid exposure time (AET), total reflux episodes, proximal acidic reflux episodes, and proximal weakly acidic reflux episodes were significantly higher in the HGMUE group than in the control group (P < 0.05). The salivary pepsin test showed a sensitivity of 85.9% and specificity of 56.9% for diagnosing GERD using the optimal cut-off value of 75 ng/mL. One hundred and seven (69.9%) and 46 (30.1%) HGMUE patients were categorized as pepsin (+) and pepsin (-), respectively when 75 ng/mL was used as a cut-off value. Male sex, RSI, AET, and proximal acid reflux episodes were positive predictive factors for the occurrence of pepsin (+) in HGMUE patients.

CONCLUSIONS

GERD, especially GERD with proximal acid reflux and related symptoms, was common in HGMUE patients. The salivary pepsin test could be an additional useful test for testing reflux in HGMUE patients, but it will not replace the MII-pH.