Pepsin as a biomarker for laryngopharyngeal reflux in children with laryngomalacia

Inflammatory Causes of Dysphagia in Children

Gastroesophageal reflux (GER) and eosinophilic esophagitis (EoE) are the most common inflammatory causes of pediatric dysphagia, but several other less prevalent conditions should be considered. These conditions can affect one or several aspects of the swallowing process. In some inflammatory conditions dysphagia may be an early symptom. Esophagoscopy and instrumental swallow studies are often needed to determine the underlying diagnosis and best treatment plan. In some inflammatory conditions dysphagia can portend a worse outcome and need for more aggressive treatment of the underlying condition. Consultations with speech language pathology, gastroenterology, dietetics, allergy/immunology and/or rheumatology are often needed to optimize management.

The Real Relevance of Nonacid Reflux in Pediatric Patients

Gastroesophageal reflux (GER) is one of the most common presenting complaints to pediatric gastroenterologists, and a wide variety of symptoms in children are potentially attributable to typical or atypical GER. While reflux diagnosis and treatment paradigms classically have focused on targeting acid, there is a growing recognition of the prevalence and significance of nonacid GER in both children and adults. This review explores the role of nonacid reflux in pediatric patients, including definitions, associations with symptoms, pathophysiologic mechanisms, and treatment implications.

The Protease Inhibitor Amprenavir Protects against Pepsin-Induced Esophageal Epithelial Barrier Disruption and Cancer-Associated Changes

Gastroesophageal reflux disease (GERD) significantly impacts patient quality of life and is a major risk factor for the development of Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC). Proton pump inhibitors (PPIs) are the standard-of-care for GERD and are among the most prescribed drugs in the world, but do not protect against nonacid components of reflux such as pepsin, or prevent reflux-associated carcinogenesis. We recently identified an HIV protease inhibitor amprenavir that inhibits pepsin and demonstrated the antireflux therapeutic potential of its prodrug fosamprenavir in a mouse model of laryngopharyngeal reflux. In this study, we assessed the capacity of amprenavir to protect against esophageal epithelial barrier disruption in vitro and related molecular events, E-cadherin cleavage, and matrix metalloproteinase induction, which are associated with GERD severity and esophageal cancer. Herein, weakly acidified pepsin (though not acid alone) caused cell dissociation accompanied by regulated intramembrane proteolysis of E-cadherin. Soluble E-cadherin responsive matrix metalloproteinases (MMPs) were transcriptionally upregulated 24 h post-treatment. Amprenavir, at serum concentrations achievable given the manufacturer-recommended dose of fosamprenavir, protected against pepsin-induced cell dissociation, E-cadherin cleavage, and MMP induction. These results support a potential therapeutic role for amprenavir in GERD recalcitrant to PPI therapy and for preventing GERD-associated neoplastic changes.

Pediatric Laryngopharyngeal Reflux: An Evidence-Based Review

Purpose: Pediatric laryngopharyngeal reflux (P-LPR) is associated with the development of common otolaryngological symptoms and findings. In the present study, the findings about epidemiology, clinical presentation, diagnostic and therapeutic outcomes of pediatric population were reviewed. Methods: A PubMed, Cochrane Library, and Scopus literature search was conducted about evidence-based findings in epidemiology, clinical presentation, diagnostic and therapeutic outcomes of P-LPR. Findings: The prevalence of LPR remains unknown in infant and child populations. The clinical presentation depends on age. Infants with LPR symptoms commonly have both gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux and related digestive, respiratory and ear, nose and throat symptoms. The GERD prevalence appears to decrease over the growth, and the clinical picture is increasingly associated with LPR symptoms and findings without GERD. The prevalence of LPR and proximal acid and nonacid esophageal reflux events may be high in some prevalent otolaryngological conditions (chronic otitis media, laryngolomalacia and apnea). However, the lack of use of hypopharyngeal–esophageal multichannel intraluminal impedance pH monitoring (HEMII-pH) limits the establishment of etiological associations. Proton pump inhibitors are less effective in P-LPR patients compared to GERD populations, which may be related to the high prevalence of weakly or nonacid reflux events. Conclusions: Many gray areas persist in P-LPR and should be not resolved without the establishment of diagnostic criteria (guidelines) based on HEMII-pH. The unavailability of HEMII-pH and the poor acid-suppressive therapeutic response are all issues requiring future investigations. Future controlled studies using HEMII-pH and enzyme measurements in ear, nose or throat fluids may clarify the epidemiology of P-LPR according to age and its association with many otolaryngological conditions.

Pediatric Laryngopharyngeal Reflux in the Last Decade: What Is New and Where to Next?

BACKGROUND

Laryngopharyngeal reflux may affect people of any age; still, most of the accumulated knowledge concerns adults, and evidence regarding pediatric populations remains relatively restricted. This study aims to review the most recent and emerging aspects of pediatric laryngopharyngeal reflux from the last ten years. It also attempts to identify gaps in knowledge and highlight discrepancies that future research should urgently address.

METHODS

An electronic search of the MEDLINE database was conducted, limited to January 2012 through December 2021. Non-English language articles, case reports, and studies that concerned a purely or predominantly adult population were excluded. The information from the articles with the most relevant contribution was initially categorized by theme and subsequently synthesized into a narrative form.

RESULTS

86 articles were included, of which 27 were review articles, eight were surveys, and 51 were original articles. Our review systematically maps the research done in the last decade and provides an updated overview and the current state-of-the-art in this subject.

CONCLUSIONS

Despite discrepancies and heterogeneity in accumulating research, evidence gathered so far endorses a need for refining an escalating multiparameter diagnostic approach. A step-wise therapeutic plan appears to be the most reasonable management approach, starting with behavioral changes for mild to moderate, uncomplicated cases and escalating to personalized pharmacotherapy options for severe or nonresponsive cases. Surgical options could be considered in the most severe cases when potentially life-threatening symptoms persist despite maximal medical therapy. Over the past decade, the amount of available evidence has been gradually increasing; however, its strength remains low. Several aspects remain markedly under-addressed, and further adequately powered, multicenter, controlled studies with uniformity in diagnostic procedures and criteria are urgently needed.

Correlation of Esophageal Mean Nocturnal Baseline Impedance With Markers of Laryngopharyngeal Reflux

OBJECTIVES

Mean nocturnal baseline impedance (MNBI) is a measure of the esophageal epithelial barrier function calculated via high-resolution impedance manometry and can be used as a diagnostic tool and treatment response predictor for gastroesophageal reflux disease (GERD). However, its utility for laryngopharyngeal reflux (LPR) has been minimally studied. We aimed to investigate the relationship of MNBI between patients with suspected LPR, healthy controls, and their 24-h multichannel intraluminal impedance-pH (MII-pH) study results.

METHODS

Retrospective patient series analysis was performed of patients with suspected LPR and healthy controls who underwent 24-h MII-pH monitoring. MNBI values were calculated from impedance channels at the level of the hypopharynx, proximal esophagus, and distal esophagus. We compared these MNBI values between the subject groups with secondary analysis on MII-pH results, reflux symptom index, reflux findings score, DeMeester score, and salivary pepsin levels.

RESULTS

Twenty-three patients with suspected LPR and 14 healthy controls were enrolled. Decreased distal esophageal MNBI was found to be significantly decreased in patients with suspected LPR compared with healthy controls (p < 0.01) and in subjects with positive MII-pH studies compared to negative MII-pH studies (p < 0.01). There were no significant correlations of MNBI at the hypopharynx or proximal esophagus.

CONCLUSION

Distal esophageal MNBI has significant correlations with many phenotypic and biological markers of LPR. These findings indicate that MNBI has the potential to be applied to LPR, similar to its emerging use as a diagnostic tool and treatment response predictor for GERD.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Initiation of acid suppression therapy for laryngomalacia

OBJECTIVE

Evidence supporting the use of acid suppression therapy (AST) for laryngomalacia (LM) is limited. The objective of this study was to determine if outpatient-initiated AST for LM was associated with symptom improvement, weight gain, and/or avoidance of surgery.

METHODS

A retrospective cohort was reviewed at a tertiary-care children's hospital. Patients were included if they were diagnosed with LM at ≤6 months of age, seen in an outpatient otolaryngology clinic between 2012 and 2018, and started on AST. Primary outcomes were improvement of airway and dysphagia symptoms, weight gain, and need for surgery. Severity was assessed by symptom severity.

RESULTS

Of 2693 patients reviewed, 199 met inclusion criteria. Median age of diagnosis was 4 weeks (range: 0-29 weeks). LM was classified as mild/moderate (71.4%) and severe (28.6%) based on symptom severity. Severity on flexible fiberoptic laryngoscopy (FFL) was not associated with clinical severity. Weight percentile, airway symptoms, and dysphagia symptoms improved within the cohort. In total, 26.1% underwent supraglottoplasty (SGP). In multivariate analysis, only severe LM on FFL was predictive of SGP (OR: 7.28, 95%CI: 1.91-27.67, p = .004).

CONCLUSION

Clinical symptom severity did not predict response to AST raising the question of utility of AST in LM. Severity of LM based on FFL, not clinical severity, was associated with decision to pursue SGP. Prospective randomized trials are needed to better understand the role of AST in LM.

LEVEL OF EVIDENCE

Level 3.

Association of Pepsin With Inflammatory Signaling and Effusion Viscosity in Pediatric Otitis Media

OBJECTIVE

Otitis media (OM) is a common inflammatory disease spectrum. Cytokine signaling, neutrophil activity, and mucin hypersecretion during recurrent and chronic OM contribute to persistent, viscous middle ear (ME) effusions, hearing loss, and potential for developmental delay. Extraesophageal reflux (EER), specifically pepsin, triggers inflammatory signaling in respiratory mucosa and is associated with OM. The objective of this study was to investigate the association of pepsin with ME inflammatory signaling and the outcomes and examine causality in vitro.

STUDY DESIGN

Cross-sectional study.

METHODS

ME fluid (MEF) and preoperative audiometric data were collected from 30 pediatric subjects undergoing tympanostomy tube placement for recurrent OM or OM with effusion. MEF viscosity was characterized by the surgeon. Pepsin, inflammatory molecules, and mucin were assayed by enzyme-linked immunosorbent assay (ELISA). ME epithelial primary culture was exposed to 0.1 to 1 mg/ml pepsin at pH 5, 6, and 7 for 30 minutes, and cytokine expression was assayed via qPCR.

RESULTS

Pepsin was observed in the MEF of 77% of patients (range 71-2,734 ng/ml). Pepsin correlated with effusion viscosity, interleukins -6 and -8, neutrophil elastase, and mucin 5B (P < .05). Pepsin-negative MEF was more frequently absent of interleukin 8 or mucin 5B (P < .05). Weak acid was generally insufficient to elicit cytokine expression in ME cells in vitro, however, pepsin induced IL6, IL8, and TNF at pH 7 (P < .05) and weak acid (pH 6) facilitated a response at lower pepsin concentration.

CONCLUSIONS

Pepsin may contribute to inflammatory signaling, persistent viscous effusion, and poorer OM outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Inspiratory stridor of newborns and infants admitted to a paediatric ENT outpatient clinic: diagnostic approach and therapeutic outcome

The main objective was to analyse the use of rigid laryngotracheoscopy under general anaesthesia (GA) and endoscopic surgery in the management of inspiratory stridor in patients referred to a paediatric ENT outpatient clinic. The secondary objective was to analyse the aetiological diagnoses made and their therapeutic management. This is a prospective study including all newborns and infants, corresponding to 190 patients, presenting for the first time in consultation for inspiratory stridor from January 2015 to December 2017. A consultation form was filled out after each consultation and added to a database; a management algorithm was used to determine which patients required a rigid laryngotracheoscopy. A 17.9% (n = 34) of the patients required rigid laryngotracheoscopy, of whom 12.6% (n = 24) underwent concomitant endoscopic surgery. A 65.8% (n = 125) of the patients were diagnosed with laryngomalacia, 21.1% (n = 40) with isolated posterior excess of mucosa, 9.5% (n = 18) with another diagnosis and 3.7% (n = 7) with a normal examination. The presence of comorbidity was associated (p < 0.001) with the use of rigid laryngotracheoscopy and endoscopic surgery.Conclusion: Rigid laryngotracheoscopy under GA was required in one in five to six patients. Conservative management with strict follow-up may be appropriate in a large number of patients, especially those with laryngomalacia. What is Known: • Previous research has established that laryngomalacia is the main aetiology of stridor. • Comorbidities are linked with a poor tolerance of stridor. What is new: • About one in five to six patients seen in consultation for stridor will require a trip to the operative room (and one in eight will require endoscopic surgery). • Laryngomalacia and isolated posterior excess of mucosa account for 85-90% of the patients seen in consultation for stridor.

Relationship Between Pepsin Expression and Dysplasia Grade in Patients With Vocal Cord Leukoplakia

OBJECTIVE

To measure pepsin expression in patients with vocal fold leukoplakia and elucidate its clinical significance.

STUDY DESIGN

Retrospective analysis of pathologic archive specimens.

SETTING

Affiliated university hospital.

SUBJECTS AND METHODS

The study included 45 patients with vocal fold leukoplakia and 19 with vocal fold polyps who underwent surgical treatment between December 2013 and July 2016. Masses were detected on both vocal cords in 5 patients with vocal fold leukoplakia and in 1 patient with vocal fold polyps. Immunohistochemistry was used to assess pepsin expression. In addition, the relationship of pepsin expression level with clinical characteristics of vocal fold leukoplakia was assessed.

RESULTS

The rate of pepsin expression was high in the polyp group (75%) and the leukoplakia group (68%); however, the difference between groups was not significant (P > .05). Pepsin expression significantly increased according to grade of dysplasia (mild, 57.1%; moderate, 88.9%; severe, 100.0%; P = .034). Similarly, the percentage of lesions that exhibited strongly positive pepsin expression increased with the grade of dysplasia (mild, 37.1%; moderate, 66.7%; severe, 100.0%; P = .005). The leukoplakia recurrence rate was higher in patients with positive pepsin expression than in patients with negative pepsin expression but without a significant difference (P > .05).

CONCLUSION

Our study suggests that pepsin was associated with the grade of dysplasia of vocal cord leukoplakia. Further investigation with appropriate control groups and controlling for other risk factors, such as smoking or alcohol consumption, is needed.

Use OF NBI for the assessment of clinical signs of rhino-pharyngo-laryngeal reflux in pediatric age: Preliminary results

OBJECTIVES

Laryngopharyngeal reflux (LPR) is a complex problem in pediatric population: diagnosis and clinical presentation are still controversial. Classic white light endoscopy shows some pathognomonic signs of LPR in children, such as thickening of pharyngo-laryngeal mucus, the cobblestoning aspect of pharyngeal mucosa, arytenoid edema/hyperemia, nodular thickening/true vocal cord edema, hypertrophy of the posterior commissure, subglottic edema. The NBI (Narrow Band Imaging) technology, generally used in oncology, allows to study neoangiogenesis and hypervascularization of the mucosa, common aspects in both chronic inflammation and neoplastic transformation. The aim of our study was to evaluate the added value of this technology in identifying the main laryngopharyngeal reflux sign in a pediatric population.

METHODS

We evaluated at the Otolaryngology Unit of the "Fondazione Policlinico A. Gemelli" hospital and the Airway Surgery Unit of the "Bambino Gesù" Children's Hospital 35 patients aged from 2 months to 16 years divided into two groups in the period between November 2017 and May 2018. Group A included patients with clinical suspicion of LPR after gastroenterologist evaluation and Group B included patients who underwent an endoscopic evaluation for the assessment of recurrent respiratory symptoms such as stridor, recurrent croup, wheezing and persistent cough. We performed an endoscopic evaluation by white light and NBI for each patient, comparing the results of both methods to evaluate signs of pharyngo-laryngeal reflux and to calculate the value of reflux finding score (RFS).

RESULTS

The analysis of the data showed: for Group A an average value of RFS with white light of 11,84 (range 8-17, standard deviation 2,52 ± 0,57) and with NBI of 13,63 (range 10-17, standard deviation 2,13 ± 0,49); for Group B the analysis of the data showed an average value of RFS with white light of 10,06 (range 8-14, standard deviation 2,32 ± 0,58) and with NBI of 12,50 (range 9-18, standard deviation 2,63 ± 0,65). The comparison between the two methods resulted significant. Furthermore evaluation by NBI allowed to highlight other signs of pharyngo-laryngeal reflux, characteristic of pediatric age and not included in RFS, in particular cobblestone aspect of the hypopharingeal mucosa, phlogosis of the tonsillar crypts and adenoid surface, hyperemia and hypervascularization of subglottic and tracheal mucosa.

CONCLUSION

Although still preliminary our results represent an interesting starting point for further studies, because they underline the potentiality of NBI endoscopy in LPR evaluation and how this technology could improve the identification of reflux signs.

Detection of Pepsin in Oral Secretions of Infants with and without Laryngomalacia

Objectives:

Laryngomalacia is a common cause of stridor in infants and is associated with laryngopharyngeal reflux (LPR). Although pepsin in operative supraglottic lavage specimens is associated with severe laryngomalacia, detection of pepsin in oral secretions has not been demonstrated in an outpatient setting.

Methods:

Children <2 years old with laryngomalacia diagnosed by flexible laryngoscopy and children without stridor were selected. Oral secretion samples were obtained in clinic from all subjects. Pepsin, IL-1β, and IL-8 enzyme-linked immunosorbent assays were performed to determine presence of LPR.

Results:

Sixteen laryngomalacia and sixteen controls were enrolled. Pepsin was detected more frequently in oral secretions of patients with laryngomalacia (13/16) than in controls (2/16; P < .001). Four patients with laryngomalacia developed symptoms requiring supraglottoplasty. Presence and level of salivary pepsin was not significantly associated with need for surgical management, nor were the levels or presence of IL-1β or IL-8 significantly associated with presence or level of pepsin, diagnosis of laryngomalacia, or need for operative management.

Conclusion:

Pepsin in saliva appears to be associated with laryngomalacia, suggesting a role for salivary pepsin as a noninvasive marker of LPR in patients with laryngomalacia. Future studies will determine the utility of this test in laryngomalacia.

Correlation of salivary and nasal lavage pepsin with MII-pH testing

OBJECTIVES

Laryngopharyngeal reflux (LPR) is a common upper airway disease. Salivary pepsin is a proposed marker for LPR; however, the optimal time for collection of specimens for pepsin detection and pepsin's presence in the oral and nasal secretions relative to concurrent multichannel intraluminal impedance-pH (MII-pH) monitoring are unknown.

STUDY DESIGN

Prospective case-control study with an experimental design.

METHODS

Patients undergoing MII-pH testing for evaluation of LPR and asymptomatic control subjects were selected. Nasal lavage and saliva samples were collected in the clinic prior to MII-pH probe placement. Additional saliva samples were obtained an hour after each meal and upon waking the following morning. Nasal lavage and salivary pepsin were measured by ELISA.

RESULTS

Twenty-six patients undergoing MII-pH testing and 13 reflux-free control patients were enrolled. Salivary pepsin was detected in 11 of 26 patients with suspected LPR and 0 of 13 controls. Pepsin was most frequently detected in the specimen provided upon waking at an average concentration of 186.9 ng/mL. A significant correlation was observed between salivary pepsin in waking samples to MII-pH measurements, including reflux bolus duration, and proximal and distal recumbent reflux episodes (P < 0.05). A significant correlation was also observed between salivary pepsin upon waking or sinus lavage and reflux symptom index (P < 0.05).

CONCLUSION

Pepsin in salivary and nasal lavage samples demonstrated an association with MII-pH-documented LPR. Pepsin detection was most frequent in morning samples, supporting use of morning salivary pepsin levels as a potential noninvasive technique for LPR diagnosis.

LEVEL OF EVIDENCE

2 Laryngoscope, 130:961-966, 2020.

Detection of pepsin and IL-8 in saliva of adult asthmatic patients

Objective: Asthma and gastric reflux disease are widespread and often coexisting diseases with complex interactions, leading some to suspect that asthma symptoms of patients with reflux may improve with anti-reflux therapy. The objective of this study was to determine whether pepsin in saliva, indicative of airway reflux, could be detected in patients with asthma of varying severity and test the requirement of citric acid as a pepsin preservative. Methods: Saliva samples were collected in the clinic (with/without citric acid) and upon waking the following morning from 25 asthmatic patients. Enzyme-linked immunosorbent assay was performed for pepsin and interleukin-8 (IL-8), an inflammatory cytokine induced by pepsin in other airway epithelia. Pepsin induction of IL-8 was tested in a lung epithelial cell culture model. Results: Pepsin was detected in saliva from 14/25 patients (56%; mean concentration of pepsin in specimens where observed ±SD =80.3±87.5 ng/mL); significant agreement was found between samples collected in the presence/absence of citric acid. No significant associations were found with pepsin and clinical measures of asthma severity. IL-8 was detected in saliva from 22/25 patients (88%; mean IL-8 in all specimens where observed =3.27±3.91 ng/mL). IL-8 was significantly upregulated in human lung epithelial cells exposed to pepsin at pH7 in vitro (P=0.041). Conclusion: In summary, more than half of the asthma patients in this study were found to have pepsin in their saliva, indicative of airway reflux. These data support the use of salivary pepsin as a noninvasive tool for future investigation of airway reflux in a larger cohort. The data further suggest that collection in citric acid as a sample preservative is not warranted and that pooling of multiple saliva samples collected at various timepoints may improve sensitivity of pepsin detection and reduce costs incurred by multiple sample analysis in future studies.

Complete polysomnographic parameters in infants with severe laryngomalacia prior to and after supraglottoplasty

INTRODUCTION

Laryngomalacia is the most common congenital laryngeal anomaly. Because of supraglottic prolapse, laryngomalacia may be associated with obstructive sleep apnea (OSA) and sleep disturbances. The effects of OSA and sleep disorders in children include failure to thrive, cognitive and behavioral disturbances, cardiovascular compromise, and an association with sudden infant death syndrome.

OBJECTIVE

To evaluate the presence of OSA and sleep disturbances in children with severe laryngomalacia through complete nocturnal polysomnography, as well as to establish the effects of supraglottoplasty in each of the polysomnographic parameters.

RESULTS

Nine infants with severe laryngomalacia were included, all with a complete polysomnographic study prior to and after supraglottoplasty. The average age was 5.5 months. All patients presented an Apnea-Hypopnea Index (AHI) within the range of severe OSA. After supraglottoplasty, a significant reduction in AHI was found, from 34.87 ± 20.34 to 9.44 ± 5.28 after surgery (p: 0.022). Additionally, sleep efficiency had a significant increase, from 21.4% to 56.29% of total sleep time (p: 0.0013). All patients presented a significant decrease in obstructive apnea episodes (p < 0.0001), as well as in hypopnea episodes (p: 0.0154). The mean and minimum peripheral oxygen saturation (SpO2) had a significant increase after supraglottoplasty from 88.2% to 94.09% (p: 0.0002), and from 81.01% to 89.33% (p < 0.0001), respectively.

CONCLUSION

Polysomnography (PSG) may provide better surgical sustenance in infants with severe laryngomalacia and OSA, as well as, serving as a monitoring tool of success. However, the surgical decision should not be reduced to polysomnographic results, and a good history and examination remain as the fundamental criteria.