Pepsin In Saliva Research Articles

A biosensor based on carbon dots-protein interactions for specific and sensitive detection of pepsin in saliva

Salivary pepsin has emerged as a promising biomarker for rapid screening and diagnosis of gastroesophageal reflux disease (GERD). Pepsin mainly exists in strongly acidic environments and exhibits its highest activity. However, the poor stability of most fluorescent sensors in strong acidic environments brings a significant challenge for pepsin detection. Herein, an innovative biosensor was developed for the highly specific and sensitive detection of pepsin on the basis of green-emitting ionic liquid-based carbon dots (G-IL-CDs) conjugated with whey proteins (WPs). The G-IL-CDs exhibited aggregation-induced fluorescence enhancement when interacting with WP, and the fluorescence intensity decreased after incubation with pepsin due to the disruption of the aggregation structure. This strategy is highly selective for pepsin due to the strongly acidic environment in which other proteases are inactivated. Under optimal experimental conditions, this biosensor successfully detected pepsin in real human saliva with a satisfying recovery. Furthermore, this study not only developed a CDs-based sensor for detecting pepsin but also laid a solid theoretical foundation for the future development of novel biosensors combining CDs and proteins.

Enhanced modified poly-tyrosine voltammetric sensor for the quantification detection of salivary pepsin

Pepsin as an aspartic acid protease member and one of the three foremost proteolytic enzymes in the digestive system is essential to be detected. An electrochemically polymerized tyrosine film on carbon paste electrode (pTyr/CPE) has been synthesized by electro-polymerization donating an affordable electrochemical sensor to sense salivary pepsin as a diagnostic technique for gastroesophageal reflux disease (GRD) due to saliva collection is non-invasive and relatively comfortable. The pTyr/CPE was applied for Voltammetric sensing of pepsin and its quantification in phosphate buffer solution of pH 2.0 (PBS). Scanning electron microscopy (SEM) was conducted to learn the surface morphology. Cyclic voltammetry (CV), differential pulse voltammetry (DPVs), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) were developed to realize the electrocatalytic activity of the sensor. The pTyr/CPE proceeded as a sensitive detector to pepsin with two linear ranges from 1 to 20 & 20 to 100 ng/mL donating two limits of detection as 0.5 & 0.09 ng/mL, respectively, and high selectivity toward pepsin, as well as stability and fast response of 1.5 s. Consequently, it is guessed that the pTyr/CPE sensor could be supportive for the initial diagnosis of GRD through the detection of pepsin in saliva. Finally, we quantified the pepsin levels in saliva samples of LPR patients (n = 2), showing that the results were agreeable with those from the electrochemical sensor.

A double-blind randomized clinical trial of inflammatory cytokine and pepsin levels in the saliva of patients with voice prostheses.

Tracheoesophageal speech is one of the most effective method used for voice rehabilitation after laryngectomy. The main limitation is the need for periodic voice prothesis (VP) replacements. The process of developing VP usage complications is still unexplored. The aim of this study was to assess the level of cytokines (IL-1β, IL-6, IL-8, IL-10, TNFα) and pepsin in saliva as potential factors reducing VP longevity. Prospective double-blind randomized clinical trial was conducted (NCT04268459). Patients were randomly divided into two groups depending on VP replacement regimen (regular-every 3 months, or irregular-when complications occur). Levels of IL-1β, IL-6, IL-8, IL-10, TNFα, and pepsin in saliva samples (fasting and after eating) of laryngectomized patients were measured using ELISA tests. Fifty-two patients (26 in both groups) with control group (7 patients) participated in the study. The level of IL-1β, IL-6, IL-8, IL-10, TNFα, and pepsin did not differ according to regularity of VP replacements (p = 0.301-0.801). IL-6 levels were significantly higher when VP complications occurs (p = 0.012). The saliva components were not significantly different depending on the frequency of VP replacements. IL-6 plays an important role in the development of VP use complications.

Diagnostic value associated with the combination of saliva pepsin and microorganisms in functional heartburn and gastroesophageal reflux disease.

Heartburn is a common symptom shared by both gastroesophageal reflux disease (GERD) and functional heartburn (FHB), which can make it challenging to differentiate between the two conditions. However, examining oral manifestations of GERD can be a cost-effective and readily available method to aid in this differentiation process. It may serve as a valuable tool in distinguishing GERD from FHB.

Elevated Saliva Pepsin Concentration as a Risk Factor for Asthma in Children with Allergic Rhinitis: A Preliminary Study.

This study aimed to explore whether saliva pepsin concentration (SPC) could be regarded as a risk factor for the occurrence and unfavorable control of asthma in children with allergic rhinitis. A prospective study was conducted on a group of 20 consecutive children newly diagnosed with allergic rhinitis and asthma (referred to as the asthma group). All these children underwent fractional exhaled nitric oxide (FeNO) measurement, lung function tests, and assessment of asthma control using the 7-item Childhood Asthma Control Test (C-ACT) score. Simultaneously, a control group consisting of 20 children with simple allergic rhinitis, matched for baseline characteristics, was included. SPC measurement was performed in the two groups. The SPC value was significantly higher in the asthma group than that in the control group (165.0 ± 82.8 ng/mL vs 68.4 ± 34.5 ng/mL) (P < 0.001). In the asthma group, SPC was independently associated with FeNO, the ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC), and forced expiratory flow at 50% and 75% of FVC (FEF50 and FEF75) (all P < 0.05). The severity of nasal symptoms evaluated by the visual analogue scale (N-VAS) was independently associated with FEF75, the maximal mid-expiratory flow (MMEF), and C-ACT score (P < 0.05). Direct pepsin exposure and uncontrolled nasal symptoms may play crucial roles in the pathogenesis and progression of childhood allergic asthma. The SPC value can be considered as a risk factor for asthma in children with allergic rhinitis.

Diagnostic Value of Fasting and Bedtime Saliva Pepsin Measurements in Laryngopharyngeal Reflux.

The pepsin test is an emerging non-invasive diagnostic approach for laryngopharyngeal reflux (LPR). The aim of this study was to investigate the diagnostic value of multiple salivary pepsin tests for detecting LPR. Patients with suspected LPR and asymptomatic individuals were consecutively recruited from January 2020 to November 2022. Patients benefited from hypopharyngeal-esophageal impedance-pH monitoring (HEMII-pH) and fasting and bedtime saliva collections to measure oral pepsin. The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were calculated considering fasting, bedtime, and the highest values of the pepsin tests at ≥16, ≥36, ≥45, and ≥100 ng/mL cutoffs. The pepsin test was adequately performed in 147 LPR patients and 32 controls. The pepsin tests were 81.6%, 74.8%, and 61.5% sensitive at cutoffs of ≥16, ≥45, and ≥100 ng/mL, respectively. The PPVs were 93.0%, 94.0%, and 94.8%, respectively. The highest specificity (81.8%) was found for the fasting pepsin test at a cutoff of 100 ng/mL. The highest sensitivity (81.6%) was found by considering the highest measured pepsin test at the ≥16 ng/mL threshold. The measurement of fasting saliva pepsin was associated with the highest sensitivity and specificity value. At ≥16 ng/mL, 27 patients had negative findings, indicating that 18.4% (27/147) of the true positive cases were missed by considering the highest pepsin test. The receiver operating characteristic curve reported that a cutoff of 21.5 was 76.9% sensitive and 62.5% specific, while the PPV and NPV were 91.1% and 38.2%, respectively. The consideration of the highest concentration of the fasting and bedtime saliva pepsin collections at a cutoff of 21.5 was associated with the best detection rate and sensitivity of the pepsin tests.

Determination of pepsin in human saliva using pepsin-susceptible peptide reporter and colorimetric dipstick assay: a prospective, cross-sectional study.

A simple and effective pepsin detection assay is reported based on a pepsin-susceptible peptide (PSP) reporter degradation strategy. PSP, which can be specifically cleaved by pepsin, was modified with fluorescein isothiocyanate (FITC) and biotin at the N- and C-terminals to be used as a reporter for colorimetric detection of dipsticks. A universal lateral flow dipstick consisting of a streptavidin test line for biotin binding and a sample pad immobilized with a gold-labeled polyclonal (rabbit) anti-FITC antibody was used to verify PSP-based pepsin detection. When the PSP reporter reacts with pepsin in a tube, it cleaves into two fragments, and the cleaved fragments do not display any color on the test line. Therefore, the higher the concentration of pepsin is, the greater is the decrease in test line intensity (IT-line) and the higher is the control line intensity (IC-line). First, the PSP cleavage and dipstick assay conditions for pepsin detection was optimized. The ratio of color intensity (IT-line/IC-line) of PSP-based dipstick assay showed a linear relationship with log concentration of pepsin ranging between 4 and 500 ng/mL (R2 = 0.98, n = 6), with a limit of detection of 1.4 ng/mL. It also exhibited high specificity and good reproducibility. Finally, pepsin levels were quantified in saliva samples from healthy controls (n = 34) and patients with laryngopharyngeal reflux (LPR, n = 61). Salivary pepsin levels were higher in patients with LPR than in healthy controls. The salivary pepsin levels correlated with those measured using a conventional enzyme-linked immunosorbent assay kit. Therefore, this PSP-based dipstick assay is a convenient tool for assessing salivary pepsin levels.

Laryngopharyngeal Reflux Scoring in a Pediatric Population

In recent years, the prevalence of laryngopharyngeal reflux has risen, especially among pediatric patients. The diagnosis of laryngopharyngeal reflux relies on patient history and clinical assessment using the Reflux Finding Score and Reflux Symptom Index as crucial diagnostic tools. Some studies have proposed a link between pepsin and laryngopharyngeal reflux, potentially triggering palatine tonsil hypertrophy. Our study aimed to investigate the correlation between laryngeal and pharyngeal manifestations of laryngopharyngeal reflux through two questionnaires and the presence of pepsin in saliva and palatine tonsils in a pediatric population. Pepsin in saliva was detected using a Western blot method, while immunohistochemistry assessed its presence in palatine tonsils. Although no statistically significant differences in Reflux Finding Score and Reflux Symptom Index were found between the immunohistochemistry-positive (IHC-positive) and immunohistochemistry-negative (IHC-negative) groups, median reflux symptom index and Reflux Finding Score values consistently trended higher in the IHC-positive group. This suggests a potential connection between elevated index values and pepsin presence in tonsillar tissue. Further investigations are essential to fully comprehend the clinical implications of these findings.

Portable and Rapid Fluorescence Turn-On Detection of Total Pepsin in Saliva Based on Strong Electrostatic Interactions.

Salivary pepsin has been proposed as a promising diagnostic marker for gastroesophageal reflux disease (GERD). However, the activity of human pepsin is strongly influenced by pH, and the acidic condition (pH ∼ 2) is optimal, which is a contradiction for the pepsin detection kit based on its catalytic activity. Thus, its accurate quantification in saliva (neutral pH) by readily rapid tools with simplicity and low cost is still challenging. Herein, a convenient fluorescence assay has been developed for the rapid detection of pepsin at neutral pH based on its electrostatic interaction with SYBR Green (SG) rather than the bioactivity. At neutral pH, the positively charged SG fluorophore can be effectively adsorbed by the negatively charged pepsin due to the low isoelectric point (pI) and large molecular size of pepsin. Thus, the molecular rotation of SG is limited, and its fluorescence intensity is significantly increased. The strategy was further confirmed to have the same fluorescence response as that of normally active and inactivated pepsin. Due to the unique pI of pepsin, the fluorescence strategy is highly selective for pepsin compared to other proteins. On the basis of this strategy, a smartphone-based fluorescence capture device integrated with a programmed Python program was fabricated for both color recognition and the accurate detection of pepsin within 3 min. Under the optimal conditions, this turn-on sensor allowed for the on-site analysis of pepsin with a detection limit of 0.2 μg/mL. Moreover, this strategy was successfully used to assess salivary pepsin to aid in the noninvasive diagnosis of GERD.

Usefulness of pepsin saliva measurement for the detection of primary burning mouth syndrome related to reflux.

To study the diagnostic value of salivary pepsin tests for detecting laryngopharyngeal reflux (LPR) in patients with primary burning mouth syndrome (BMS). Patients with BMS and asymptomatic individuals were consecutively recruited from September 2018 to June 2023. Patients underwent hypopharyngeal-esophageal impedance pH-monitoring (HEMII-pH) and saliva collections to measure pepsin. Stomatology evaluation was carried out to exclude other causes of BMS. Oral, pharyngeal and laryngeal signs and symptoms were evaluated with Reflux Sign Assessment (RSA) and Reflux Symptom Score (RSS). Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of pepsin test were calculated considering the highest values of pepsin tests at ≥ 16, ≥ 36, and ≥ 100ng/mL cutoffs. Receiver operating characteristic curve (ROC) was evaluated. Forty-nine patients with both BMS and LPR at the HEMII-pH and 21 asymptomatic individuals were recruited. Pepsin test was 83.7%, 79.6%, and 71.4% sensitive at cutoffs ≥ 16, ≥ 36, and ≥ 100ng/mL, respectively. The ROC analysis reported that a threshold of ≥ 21.5ng/mL was associated with sensitivity, specificity, PPV and NPV of 81.6%, 81.0%, 90.1% and 65.4%, respectively. The severity score of burning mouth symptom was significantly associated with the saliva pepsin concentration (rs = 0.263; p = 0.029) and the oral RSA (rs = 0.474; p = 0.007). Pepsin test is a valuable diagnostic approach for detecting LPR in patients with BMS. Patients with high level of saliva pepsin reported more severe burning mouth symptoms. Future studies are needed to confirm the role of LPR in the primary BMS.

Salivary Pepsin versus Oesophageal PH Metry as a Diagnostic Test for Laryngopharyngeal Reflux Disease

Abstract Background Laryngopharyngeal reflux (LPR) is the retrograde movement of gastric contents (acid and enzymes such as pepsin) into the laryngopharynx leading to symptoms referable to the larynx/hypopharynx. Objective To evaluation of salivary pepsin as a non-invasive rapid test for diagnosis of laryngopharyngeal reflux versus oesophageal ph metry. Patients and Methods This was a prospective comparative study conducted on 50 subjects; to evaluate the salivary pepsin as a non-invasive rapid test for diagnosis of laryngo-pharyngeal reflux (LPR) versus oesophageal pH metry. Results The increase in age, laryngoscopic abnormality, and pH metry; had an independent effect on increasing salivary Pepsin; with significant statistical difference (p &amp;lt; 0.05 respectively). The increase in laryngoscopic abnormality; had an independent effect on increasing pH metry (% Time pH &amp;lt; 4); with significant statistical difference (p = 0.00002). The increase in pH metry (% Time pH &amp;lt; 4); had an independent effect on increasing the probability of LPR occurrence; with significant statistical difference (p &amp;lt; 0.005). Salivary Pepsin at a cutoff point (&amp;gt;5) predicted patients with LPR, with fair (77.9%) accuracy, sensitivity= 100% and specificity= 56% (p = 0.0001). PH metry (% Time pH &amp;lt; 4) at a cutoff point (&amp;gt;14) predicted patients with LPR, with good (87%) accuracy, sensitivity= 80% and specificity= 100% (p &amp;lt; 0.0001). Conclusion In this study we have shown that pepsin in saliva of patients with LPR is significantly higher than normal individuals, this may help as a diagnostic tool without using invasive methods for diagnosis of LPR.

Saliva pepsin measurements in the detection of gastroesophageal reflux disease in laryngopharyngeal reflux patients: a cohort study.

To study the diagnostic value of salivary pepsin measurement (Peptest) for detecting gastroesophageal reflux disease (GERD) in laryngopharyngeal reflux (LPR) patients. Patients with reflux symptoms were consecutively recruited from January 2020 to November 2022. Patients benefited from hypopharyngeal-esophageal impedance-pH monitoring (HEMII-pH), fasting and bedtime saliva collections to measure pepsin. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were evaluated for GERD and LPR patients considering the highest values of pepsin tests at ≥ 16, ≥ 75, and ≥ 216ng/mL cutoffs. The relationship between HEMII-pH, endoscopic and clinical findings, and pepsin measurements was studied. Saliva was collected in 109 LPR patients and 30 individuals with both LPR and GERD. The total number of pharyngeal reflux events was significantly higher in GERD-LPR patients compared with LPR patients (p = 0.008). The mean fasting and bedtime pepsin saliva concentrations were similar between groups. The sensitivity of Peptest in LPR patients was 30.5%, 70.2%, and 84.0% at cutoffs ≥ 16, ≥ 75 and ≥ 216ng/mL. In GERD-LPR group, Peptest was 80.0%, 70.0%, and 30.0% sensitive. At cutoff 16ng/mL, Peptest reported PPV of 20.7% and 94.8% in LPR-GERD and LPR groups, respectively. NPV were 73.9% and 8.7% in GERD-LPR and LPR groups, respectively. The consistency analysis between Peptest and HEMII-pH was not significant. Peptest was significantly associated with the number of acid pharyngeal reflux events (rs = 0.182; p = 0.032). Pepsin saliva measurements appear to be not a reliable diagnostic tool for the detection of GERD in LPR patients. Future studies are needed to determine the place of Peptest in laryngopharyngeal reflux and gastroesophageal reflux diseases.

Variability and accuracy of multiple saliva pepsin measurements in laryngopharyngeal reflux patients

ObjectiveTo study the variability and diagnostic value of multiple salivary pepsin measurements in the detection of laryngopharyngeal reflux (LPR).MethodsPatients with LPR symptoms were consecutively recruited from December 2019 to Augustus 2022. Twenty-one asymptomatic individuals completed the study. The diagnostic was confirmed with hypopharyngeal–esophageal impedance-pH monitoring (HEMII-pH). Patients collected three saliva samples during the 24-h testing period. Symptoms and findings were studied with reflux symptom score-12 and reflux sign assessment. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of pepsin measurements were calculated considering morning, post-lunch and post-dinner samples. The consistency and relationship between HEMII-pH, pepsin measurements, and clinical features were investigated.ResultsMorning, post-lunch and post-dinner saliva pepsin concentrations were measured in 42 patients. Pepsin measurements were 64.9%, 59.5%, and 59.0% sensitive for morning, post-lunch and post-dinner collections at cutoff ≥ 16 ng/mL. Considering the highest concentration of the three pepsin saliva collections, the accuracy, sensitivity, specificity and PPV were 70.5%, 73.0%; 66.7% and 78.9%, respectively. Morning pepsin measurements reported higher consistency, sensitivity, and specificity than post-dinner and post-lunch pepsin measurements.ConclusionThe collection of several saliva pepsin samples improves the detection rate of LPR. In case of high clinical LPR suspicion and negative pepsin test, a HEMII-pH study could provide further diagnostic information.

SPECIFIC FEATURES OF THE ORAL MICROBIOME IN YOUNG CHILDREN WITH ARYNGOPHARYNGEAL REFLUX AND ITS ROLE THE DEVELOPMENT OF RECURRENT RESPIRATORY DISEASES.

The aim: To examine the composition of the oral microbiome in young children with laryngopharyngeal reflux (LPR) and its role the development of recurrent respiratory diseases. Materials and methods: There were examined 38 children with physiological gastroesophageal reflux (GER), 18 children with LPR who had a medical history of recurrent bronchitis and 17 healthy children (control group). The study included the collection of anamnesis, objective examination. The qualitative and quantitative microbial composition of the upper respiratory tract was performed obtained by oropharyngeal deep swab. Salivary pepsin level and IL-8 were determined by enzyme-linked immunosorbent assay. Results: This research showed significant alterations in the oral microbiome of patients with GER and LPR as compared to healthy control. We found that gram-negative microbiota such as Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, Proteus spp. and Candida albicans were identified in children with GER and LPR compared to the healthy control. At the same time, the amount of such a representative of the normal microbiome as Streptococcus viridans in children with LPR was sharply reduced. There were established a much higher mean salivary pepsin level of the patients with LPR than in the GER and control group. We found the association between high pepsin levels, saliva IL-8 levels and frequency of respiratory pathology in children with LPR. Conclusions: Our study confirms that increased levels of pepsin in saliva are a risk factor for recurrent respiratory diseases in children with LPR.

A bovine serum albumin and squaraine dye assembly fluorescent probe for pepsin detection

Gastroesophageal reflux disease (GERD) is a highly prevalent condition. Screening for GERD remains a great challenge due to the non-specific nature of the symptoms. Now, salivary pepsin detection has become an effective tool for diagnosing GERD due to its non-invasive and highly specific advantages. However, the diagnosis of GERD by detecting pepsin in saliva still has factors such as long reaction time, poor selectivity, and low detection sensitivity, which need to be improved. In this work, bovine serum albumin (BSA) and a squaraine dye (SQ) were employed to build a BSA-SQ assembly with a fluorescent “on-off” change for rapid and sensitive detection of pepsin. In a Gly-HCl (pH = 2.6) buffer system, SQ had a significant aggregation caused-quenching (ACQ) effect. As SQ was embedded in the cavity of BSA, this improved its dispersion and inhibited the ACQ effect of SQ, resulting in enhanced fluorescence of the system. At this stage, pepsin catalyzed the hydrolysis of BSA, leading to the aggregation of SQ and the quenching of the fluorescence of BSA-SQ. The high catalytic activity of pepsin makes BSA-SQ suitable for the qualitative and quantitative detection of pepsin, showing a good linear relationship in the range of 0.5–40 μg/mL with a detection limit of 97 ng/mL. Finally, the use of this fluorescent probe method to detect pepsin in human saliva showed results consistent with conventional ELISA methods with relative errors between 0.4 and 5.5 %, confirming the great potential of BSA-SQ for the rapid diagnosis of GERD.

Analysis of symptoms and clinical signs of laryngopharyngeal reflux depending on pepsia in saliva

In the last fifty years, an epidemic of reflux disease has occurred as a result of poor eating habits, stress, and activities of the food industry. Part of this disease is laryngopharyngeal reflux, a disease characterized by the return of gastric contents to the throat and surrounding organs, leading to hoarseness, coughing, difficulty in swallowing and breathing, and ultimately the development of benign and malignant changes in the larynx. This study is aimed to examine the symptoms and signs of laryngopharyngeal reflux in the study group before and after therapy and to compare the concentration of pepsin in saliva with the above. The prospective longitudinal cohort study included 50 subjects, divided into two groups. The first group consisted of 25 subjects with laryngopharyngeal reflux. The second group consisted of 25 healthy subjects without symptoms and signs of laryngopharyngeal reflux. Symptoms and signs before and after therapy were collected using RSI and RFS questionnaires. Pepsin in saliva was measured with Peptest before and after therapy. The most pronounced symptoms are hoarseness, postnasal drip, and a feeling of "a lump in the throat". The median RSI score after three months of therapy was reduced from 20 to 8. From the first group, 7 subjects had measurable levels of pepsin in saliva, and none after therapy. In the control group, no subjects were found to have pepsin in their saliva. Significant improvement was observed in clinical findings (subglottic edema, posterior commissure hypertrophy, vocal cord edema, dense endolaryngeal secretion) after three months of therapy in subjects with LPR. No association of pepsin with LPR symptoms was observed but there is a significant positive association between pepsin and the clinical finding of erythema/hyperemia. In most cases, we start therapy with medication. It is, therefore, important to emphasize that laryngopharyngeal reflux treatment must always begin with a change in diet, lifestyle, and stress regulation. Treatment must be individual and should include a multidisciplinary team with a nutritionist, psychologist, and psychiatrist.

Expression of pepsin in nasopharyngeal carcinoma and its correlation with quality of life after radiotherapy

Objective: By analyzing the expression of pepsin in nasopharyngeal carcinoma (NPC) tissues, to investigate the correlation between laryngeal reflux (LPR) and NPC, as well as the effect of LPR on the quality of life of patients with NPC after radiotherapy. Methods: A total of 133 patients with NPC who underwent radiotherapy at the Department of Otorhinolaryngology of the Affiliated Hospital of Guizhou Medical University and the Affiliated Cancer Hospital of Guizhou Medical University from 2005 to 2019 were enrolled consecutively, including 90 males and 43 females, aged (44.32±7.47) years old. At the same period, 58 patients with chronic nasopharyngitis who underwent nasopharyngeal biopsy were selected as the control group. Immunohistochemical method was used to detect the expression of pepsin in nasopharyngeal specimens of the two groups. In addition, 188 normal individuals were selected as the normal group in the same period. NPC patients before and within 6 months after radiotherapy were inverstigated by the General Information Questionnaire and the Quality of Life Scale, and the pepsin levels in saliva of NPC patients before and after radiotherapy and the individuals in normal group were measured. SPSS 21.0 software was used for statistical analysis. Results: Pepsin expression in 133 specimens of NPC patients was strongly positive in 24 cases (18.05%), positive in 21 cases (15.79%), weakly positive in 69 cases (51.88%), and negative in 19 cases (14.29%). The specimens of control group had 10 cases of weakly positive (17.24%), 48 cases of negative (82.76%), but no strong positive or positive pepsin expression. The rate of positive pepsin expression in the NPC group was higher than that in the control group, with a statistically significant (χ2=83.15, P<0.001). The pepsin content in the saliva of NPC patients after radiotherapy ((30.31±7.82) ng/ml) was higher than that before radiotherapy ((20.47±8.21) ng/ml) and the normal group (5.11±2.13) ng/ml), and the pepsin content in saliva before radiotherapy was higher than that in the normal group, and all differences were statistically significant (all P<0.05). After radiotherapy, the five functional domains of quality of life and overall quality of life of NPC patients decreased, while the related symptom scores increased (all P<0.05). Multiple linear regression analysis showed that pepsin content in saliva was the influential factor of five functional domains of quality of life, related symptoms and overall quality of life in NPC patients after radiotherapy (all P<0.05). Conclusion: The positive rate of pepsin expression in NPC tissues is high, and the pepsin in saliva before and after radiotherapy of NPC patients is significantly higher than that in normal, suggesting that LPR may be involved in the process of NPC and affect the quality of life after radiotherapy in NPC patients.

Usefulness of matrix metalloproteinase-7 in saliva as a diagnostic biomarker for laryngopharyngeal reflux disease

Several diagnostic methods are currently being used to diagnose LPRD (laryngopharyngeal reflux disease), but have the disadvantage of being invasive, subjective, or expensive. Our purpose in this study was to investigate the correlation between pepsin and MMP-7 (Matrix Metalloproteinase-7) in pharyngeal secretions of subjects according to RSI (Reflux Symptom Index) score to find out the diagnostic value of MMP-7. We recruited 173 subjects aged between 19 and 85 years who completed the RSI scale. All samples were taken after waking up, and the amount of the pepsin and MMP-7 in saliva were measured by means of an enzyme activity assay. There was a significant increase of pepsin and MMP-7 activity in the study group with an RSI score of 13 or higher. The sensitivity and specificity of MMP-7 for predicting the possibility of an RSI of 13 or more was higher than that of pepsin. When MMP-7 and pepsin were combined, this sensitivity and specificity increased. An enzyme assay of MMP-7 in saliva may be a noninvasive and easy technique for diagnosing LPRD.

Salivary peptest for laryngopharyngeal reflux and gastroesophageal reflux disease: A systemic review and meta-analysis.

Background:A rapid lateral flow test (Peptest) to detect pepsin in saliva/sputum has been considered as a valuable method for diagnosing laryngopharyngeal reflux (LPR) and gastroesophageal reflux disease (GERD). The aim of this meta-analysis is to analyze the utility of Peptest for diagnosis of LPR and GERD.Methods:PubMed, EMBASE, and the Cochran Library (from January 1980 to 26 January 2020) were searched for pepsin in saliva for LPR/GERD diagnosis. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve data were summarized to examine the accuracy.Results:A total of 16 articles that included 2401 patients and 897 controls were analyzed. The pooled sensitivity and specificity for the diagnosis of GERD/LPR with Peptest were 62% (95% confidence interval [CI] 49%–73%) and 74% (95% CI 50%–90%), respectively. The summarized diagnostic odds ratio and area under the curve were 5.0 (95% CI 2–19) and 0.70 (95% CI 0.66–0.74), respectively.Conclusion:Peptest shows moderate diagnostic value for LPR and GERD. More studies with standard protocols should be done to verify its usefulness.

Association between gastroesophageal reflux disease and vocal fold polyps.

The aim of this study is to explore the relationship between gastroesophageal reflux disease (GERD) and vocal fold polyps (VFPs).This is a Case-Control study and was performed with the help of The Second Affiliated Hospital of Chongqing Medical University.Twenty-seven patients with VFP and 20 controls without VFP were recruited between May and October 2018. All the subjects underwent a saliva pepsin test, completed the GerdQ questionnaire and 24-hour multichannel intraluminal impedance with pH (24-h MII-pH) monitoring. Twenty-five resected VFP specimens were examined with immunohistochemical (IHC) and double immunofluorescence (IF) staining.The incidence of GERD in the VFP group was significantly higher than that in the control group (P = .003). Patients with VFP had significantly higher GerdQ scores, pepsin concentrations, and pepsin-positive rates (P < .05). Moreover, the number of proximal and upright reflux events was significantly higher in the VFP group (P < .05). The pepsin concentration in saliva showed a significant positive correlation with the pepsin levels in tissues (r2 = 0.50, P = .011). Pepsin and TGF-β1-positive cells were colocalized with CD45RO-positive cells. IHC staining showed that the majority of VFP patients had a positive expression of pepsin (20/25, 80%) and pepsin-positive cells were found in both the squamous epithelium and mesenchymal tissues. IHC staining of TGF-β1 in VFP revealed findings similar to those of pepsin staining.GERD is an important risk factor for VFP. Pepsin may promote the aggregation of immune cells, increase the local cytokines, and promote inflammatory reaction, suggesting a potential new pathogenesis for VFP. The saliva pepsin test is a reliable method for GERD diagnosis.