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Nikki Johnston - One of the best experts on this subject based on the ideXlab platform.
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The Role of Pepsin in LPR: Will It Change Our Diagnostic and Therapeutic Approach to the Disease?
Current Otorhinolaryngology Reports, 2016Co-Authors: Kendra E. Luebke, Tina L. Samuels, Nikki JohnstonAbstract:Laryngopharyngeal reflux (LPR) is the back flow of gastric contents into the laryngopharynx. It is estimated that this disease affects 20−40 % of the United States population and is commonly encountered by otolaryngologists. Patients with LPR present with symptoms due to chronic laryngeal irritation such as hoarseness and cough. Pepsin, a gastric enzyme, has been shown to be a specific and sensitive biomarker for LPR. Measurement of Pepsin in patients with LPR symptoms holds promise as a reliable diagnostic test. Studies have shown that Pepsin induces cell damage, inflammation, and neoplastic changes independently of gastric acid in an endocytosis-dependent manner. Thus, Pepsin has been proposed as a novel therapeutic target, especially for patients experiencing refractory symptoms on currently available anti-reflux medications. Further research is needed to elucidate the exact role that Pepsin plays in inflammatory and neoplastic diseases of the laryngopharynx and to develop pharmacologic agents targeting Pepsin.
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Local Synthesis of Pepsin in Barrett's Esophagus and the Role of Pepsin in Esophageal Adenocarcinoma.
Annals of Otology Rhinology and Laryngology, 2015Co-Authors: Tina L. Samuels, Craig R. Hoekzema, Jon C. Gould, Matthew I. Goldblatt, Matthew J. Frelich, Matthew E. Bosler, Nikki JohnstonAbstract:Objective:Despite widespread use of proton pump inhibitors (PPIs), the incidence of esophageal adenocarcinoma (EAC) continues to rise. PPIs reduce reflux acidity, but only transiently inactivate gastric enzymes. Nonacid reflux, specifically nonacid Pepsin, contributes to carcinogenesis in the larynx. Given the carcinogenic potential of Pepsin and inefficacy of PPIs to prevent EAC, the presence and effect of Pepsin in the esophagus should be investigated.Methods:Normal and Barrett’s biopsies from 8 Barrett’s esophagus patients were collected for Pepsin analysis via Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Human esophageal cells cultured from healthy patients were treated with Pepsin (0.01-1 mg/mL; 1-20 hours), acid (pH 4) ± Pepsin (5 minutes); real-time RT-PCR, ELISA, and cell migration were assayed.Results:Pepsin was detected in all 8 Barrett’s and 4 of 8 adjacent normal specimens. Pepsinogen mRNA was observed in 22 Barrett’s, but not in normal adjacent samples. Pepsin in...
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the presence of Pepsin in the lung and its relationship to pathologic gastro esophageal reflux
Neurogastroenterology and Motility, 2012Co-Authors: Rachel Rosen, Nikki Johnston, Kristen Hart, Umakanth Khatwa, Samuel NurkoAbstract:Background Pepsin has been proposed as a biomarker of reflux-related lung disease. The goal of this study was to determine (i) if there is a higher reflux burden as measured by pH-MII in patients that are Pepsin positive in the lung, and (ii) the sensitivity of Pepsin in predicting pathologic reflux by pH, MII, and EGD. Methods We recruited children between the ages of 1–21 with chronic cough or asthma undergoing bronchoscopy, esophagogastroduodenoscopy (EGD), and multichannel intraluminal impedance (pH-MII) probe placement. The reflux profiles were compared between those patients who were Pepsin positive and negative; proportions were compared using Chi-squared analyses and means were compared using t-testing. Key Results Only the mean number of non-acid reflux events was associated with Pepsin positivity (0.04). The sensitivity and specificity of Pepsin in predicting pathologic reflux by pH-MII or EGD was 57% and 65%, respectively. The positive predictive value of Pepsin in predicting pathologic reflux by pH, MII or EGD was 50% (11/22), and the negative predictive value was 71% (20/28). There was a significantly higher mean LLMI in patients who were Pepsin positive compared with Pepsin negative patients (81 ± 54 vs 47 ± 26, P = 0.001). Conclusions & Inferences Lung Pepsin cannot predict pathologic reflux in the esophagus, but its correlation with lung inflammation suggests that Pepsin may be an important biomarker for reflux-related lung disease.
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Pepsin as a marker of extraesophageal reflux
Annals of Otology Rhinology and Laryngology, 2010Co-Authors: Tina L. Samuels, Nikki JohnstonAbstract:Diagnosis of extraesophageal reflux (EER) currently relies on tools designed for diagnosis of gastroesophageal reflux. Such tools lack the sensitivity and reproducibility to detect the less frequent and mildly acidic reflux associated with upper airway disease. Pepsin has been posited to be a reliable biological marker of EER. Our aim was to present a comprehensive literature review of the use of Pepsin as a diagnostic marker of EER. Two methods are typically used for detection of Pepsin in the airways: enzymatic and immunologic. The limitations, advantages, and examples of use of each are discussed. Pepsin assay has been used to identify refluxate in trachea, lung, sinus, middle ear, combined sputum and saliva, and breath condensate. An immunologic Pepsin assay of combined sputum and saliva was determined to be 100% sensitive and 89% specific for detection of EER (based on pH-metry), and an enzymatic test of nasal lavage fluid (100% sensitivity and 92.5% specificity) demonstrated an increased incidence of EER in patients with chronic rhinosinusitis. Pepsin assay identified tracheal Pepsin to be an indicator of bronchopulmonary dysplasia and related mortality risk in ventilated preterm infants. Pepsin assay is a useful tool for correlation of reflux with airway disease and is a reliable diagnostic marker of EER.
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Pepsin in nonacidic refluxate can damage hypopharyngeal epithelial cells
Annals of Otology Rhinology and Laryngology, 2009Co-Authors: Nikki Johnston, Clive Wells, Tina L. Samuels, Joel H BluminAbstract:Objectives: Studies using combined multichannel intraluminal impedance with pH monitoring reveal a role for nonacidic reflux in laryngopharyngeal symptoms and injury. We have discovered that Pepsin is taken up by laryngeal epithelial cells by receptor-mediated endocytosis. This finding reveals a novel mechanism by which Pepsin could cause cell damage, potentially even in nonacidic refluxate. The objective of this study was to determine whether Pepsin, at pH 7.4 and thus in nonacidic refluxate, causes cell damage. Methods: Cultured hypopharyngeal epithelial (FaDu) cells were exposed to human Pepsin (0.1 mg/mL) at pH 7.4 for either 1 hour or 12 hours at 37°C and analyzed by electron microscopy, cytotoxicity assay, and SuperArray. Results: We report mitochondrial and Golgi complex damage in cells exposed to Pepsin at neutral pH, observed by electron microscopy. We also report cell toxicity of Pepsin at pH 7.4, measured by a cytotoxicity assay. Furthermore, using SuperArray, we found that Pepsin at pH 7.4 significantly alters the expression levels of multiple genes implicated in stress and toxicity. Conclusions: These findings are perhaps the first to explain why many patients have symptoms and injury associated with nonacidic reflux, and could have important implications for the development of new therapies for reflux, such as Pepsin receptor antagonists and/or irreversible inhibitors of peptic activity.
Yaru Wang - One of the best experts on this subject based on the ideXlab platform.
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engineering of yersinia phytases to improve Pepsin and trypsin resistance and thermostability and application potential in the food and feed industry
Journal of Agricultural and Food Chemistry, 2017Co-Authors: Peilong Yang, Huoqing Huang, Yaru WangAbstract:Susceptibility to proteases usually limits the application of phytase. We sought to improve the Pepsin and trypsin resistance of YeAPPA from Yersinia enterocolitica and YkAPPA from Y. kristensenii by optimizing amino acid polarity and charge. The predicted Pepsin/trypsin cleavage sites F89/K226 in Pepsin/trypsin-sensitive YeAPPA and the corresponding sites (F89/E226) in Pepsin-sensitive but trypsin-resistant YkAPPA were substituted with S and H, respectively. Six variants were produced in Pichia pastoris for catalytic and biochemical characterization. F89S, E226H, and F89S/E226H elevated Pepsin resistance and thermostability and K226H and F89S/K226H improved Pepsin and trypsin resistance and stability at 60 °C and low pH. All the variants increased the ability of the proteins to hydrolyze phytate in corn meal by 2.6–14.9-fold in the presence of Pepsin at 37 °C and low pH. This study developed a genetic manipulation strategy specific for Pepsin/trypsin-sensitive phytases that can improve enzyme tolerance a...
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corrigendum engineering the residual side chains of hap phytases to improve their Pepsin resistance and catalytic efficiency
Scientific Reports, 2017Co-Authors: Peilong Yang, Huoqing Huang, Yaru WangAbstract:Strong resistance to proteolytic attack is important for feed enzymes. Here, we selected three predicted Pepsin cleavage sites, L99, L162, and E230 (numbering from the initiator M of premature proteins), in Pepsin-sensitive HAP phytases YkAPPA from Yersinia kristensenii and YeAPPA from Y. enterocolitica, which corresponded to L99, V162, and D230 in Pepsin-resistant YrAPPA from Y. rohdei. We constructed mutants with different side chain structures at these sites using site-directed mutagenesis and produced all enzymes in Escherichia coli for catalytic and biochemical characterization. The substitutions E230G/A/P/R/S/T/D, L162G/A/V, L99A, L99A/L162G, and L99A/L162G/E230G improved the Pepsin resistance. Moreover, E230G/A and L162G/V conferred enhanced Pepsin resistance on YkAPPA and YeAPPA, increased their catalytic efficiency 1.3–2.4-fold, improved their stability at 60 °C and pH 1.0–2.0 and alleviated inhibition by metal ions. In addition, E230G increased the ability of YkAPPA and YeAPPA to hydrolyze phytate from corn meal at a high Pepsin concentration and low pH, which indicated that optimization of the Pepsin cleavage site side chains may enhance the Pepsin resistance, improve the stability at acidic pH, and increase the catalytic activity. This study proposes an efficient approach to improve enzyme performance in monogastric animals fed feed with a high phytate content.
Jirut Meesane - One of the best experts on this subject based on the ideXlab platform.
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extraction and characterisation of Pepsin solubilised collagens from the skin of bigeye snapper priacanthus tayenus and priacanthus macracanthus
Journal of the Science of Food and Agriculture, 2010Co-Authors: Soottawat Benjakul, Yaowapa Thiansilakul, Wonnop Visessanguan, Sittiruk Roytrakul, Hideki Kishimura, Thummanoon Prodpran, Jirut MeesaneAbstract:BACKGROUND: Fish collagen has been paid increasing attention as an alternative to the mammalian counterpart owing to the abundance of fish skin as a processing by-product. Generally, the low yield of collagen extracted using the typical acid solubilisation process has led to the use of mammalian Pepsin as an aid for increasing the yield. Alternatively, fish Pepsin, especially from tuna stomach, can be used for the extraction of Pepsin-solubilised collagen (PSC). Therefore the objective of this study was to extract and characterise PSC from the skin of bigeye snapper, a fish widely used for surimi production in Thailand. RESULTS: PSCs from the skin of two species of bigeye snapper, Priacanthus tayenus and Priacanthus macracanthus, were extracted with the aid of tongol tuna (Thunnus tonggol) Pepsin and porcine Pepsin. PSCs from the skin of both species extracted using porcine Pepsin had a higher content of β-chain but a lower content of α-chains compared with those extracted using tuna Pepsin. All PSCs contained glycine as the major amino acid and had an imino acid (proline and hydroxyproline) content of 189–193 residues per 1000 residues. Transition temperatures of PSCs were in the range 30.6–31.3 °C. Fourier transform infrared spectra revealed some differences in molecular order between PSCs extracted using porcine Pepsin and tuna Pepsin. Nevertheless, the triple-helical structure of PSCs was not affected by Pepsin digestion. Zeta potential analysis indicated that PSCs from P. tayens and P. macracanthus possessed zero net charge at pH 7.15–7.46 and 5.97–6.44 respectively. CONCLUSION: Tongol tuna Pepsin could be used as a replacement for mammalian Pepsin in PSC extraction. However, a slight difference in PSC properties was found. Copyright © 2009 Society of Chemical Industry
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extraction and characterisation of Pepsin solubilised collagens from the skin of bigeye snapper priacanthus tayenus and priacanthus macracanthus
Journal of the Science of Food and Agriculture, 2010Co-Authors: Soottawat Benjakul, Yaowapa Thiansilakul, Wonnop Visessanguan, Sittiruk Roytrakul, Hideki Kishimura, Thummanoon Prodpran, Jirut MeesaneAbstract:BACKGROUND: Fish collagen has been paid increasing attention as an alternative to the mammalian counterpart owing to the abundance of fish skin as a processing by-product. Generally, the low yield of collagen extracted using the typical acid solubilisation process has led to the use of mammalian Pepsin as an aid for increasing the yield. Alternatively, fish Pepsin, especially from tuna stomach, can be used for the extraction of Pepsin-solubilised collagen (PSC). Therefore the objective of this study was to extract and characterise PSC from the skin of bigeye snapper, a fish widely used for surimi production in Thailand. RESULTS: PSCs from the skin of two species of bigeye snapper, Priacanthus tayenus and Priacanthus macracanthus, were extracted with the aid of tongol tuna (Thunnus tonggol) Pepsin and porcine Pepsin. PSCs from the skin of both species extracted using porcine Pepsin had a higher content of beta-chain but a lower content of alpha-chains compared with those extracted using tuna Pepsin. All PSCs contained glycine as the major amino acid and had an imino acid (proline and hydroxyproline) content of 189-193 residues per 1000 residues. Transition temperatures of PSCs were in the range 30.6-31.3 degrees C. Fourier transform infrared spectra revealed some differences in molecular order between PSCs extracted using porcine Pepsin and tuna Pepsin. Nevertheless, the triple-helical structure of PSCs was not affected by Pepsin digestion. Zeta potential analysis indicated that PSCs from P. tayens and P. macracanthus possessed zero net charge at pH 7.15-7.46 and 5.97-6.44 respectively. CONCLUSION: Tongol tuna Pepsin could be used as a replacement for mammalian Pepsin in PSC extraction. However, a slight difference in PSC properties was found.
Jamie A Koufman - One of the best experts on this subject based on the ideXlab platform.
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activity stability of human Pepsin implications for reflux attributed laryngeal disease
Laryngoscope, 2007Co-Authors: Nikki Johnston, Peter W Dettmar, Bimjhana Bishwokarma, Mark O Lively, Jamie A KoufmanAbstract:OBJECTIVES/HYPOTHESIS: Exposure of laryngeal epithelia to Pepsin during extra-esophageal reflux causes depletion of laryngeal protective proteins, carbonic anhydrase isoenzyme III (CAIII), and squamous epithelial stress protein Sep70. The first objective of this study was to determine whether Pepsin has to be enzymatically active to deplete these proteins. The second objective was to investigate the effect of pH on the activity and stability of human Pepsin 3b under conditions that might be found in the human esophagus and larynx. STUDY DESIGN: Prospective translational research study. METHODS: An established porcine in vitro model was used to examine the effect of active/inactive Pepsin on laryngeal CAIII and Sep70 protein levels. The activity and stability of Pepsin was determined by kinetic assay, measuring the rate of hydrolysis of a synthetic Pepsin-specific substrate after incubation at various pH values for increasing duration. RESULTS: Active Pepsin is required to deplete laryngeal CAIII and Sep70. Pepsin has maximum activity at pH 2.0 and is inactive at pH 6.5 or higher. Although Pepsin is inactive at pH 6.5 and above, it remains stable until pH 8.0 and can be reactivated when the pH is reduced. Pepsin is stable for at least 24 hours at pH 7.0, 37 degrees C and retains 79% +/- 11% of its original activity after re-acidification at pH 3.0. CONCLUSIONS: Detectable levels of Pepsin remain in laryngeal epithelia after a reflux event. Pepsin bound there would be enzymatically inactive because the mean pH of the laryngopharynx is pH 6.8. Significantly, Pepsin could remain in a form that would be reactivated by a subsequent decrease in pH, such as would occur during an acidic reflux event or possibly after uptake into intracellular compartments of lower pH.
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sensitive Pepsin immunoassay for detection of laryngopharyngeal reflux
Laryngoscope, 2005Co-Authors: John Knight, Nikki Johnston, Peter W Dettmar, Mark O Lively, Jamie A KoufmanAbstract:OBJECTIVES/HYPOTHESIS: To determine whether measurement of Pepsin in throat sputum by immunoassay could be used as a sensitive and reliable method for detecting laryngopharyngeal reflux (LPR) compared with 24-hour double-probe (esophageal and pharyngeal) pH monitoring. STUDY DESIGN: Patients with clinical LPR undergoing pH monitoring provided throat sputum samples during the reflux-testing period for Pepsin measurement using enzyme-linked immunoadsorbent assay. RESULTS: Pepsin assay results from 63 throat sputum samples obtained from 23 study subjects were compared with their pH monitoring data. Twenty-two percent (14/63) of the sputum samples correlated the presence of Pepsin with LPR (pH < or = 4 at the pharyngeal probe), of which the median concentration of Pepsin was 0.18 microg/mL (range 0.003-22 microg/mL). Seventy-eight percent (49/63) of the samples unassociated with (pharyngeal) reflux contained no detectible Pepsin. Mean pH values for Pepsin-positive samples were significantly lower than negative samples at both esophageal probe (pH 2.2 vs. pH 5.0) (P < .01) and the pharyngeal probe (pH 4.4 vs. pH 5.8) (P < .01). When the Pepsin assay results were compared with the pharyngeal pH data for detecting reflux (events pH < or = 4), the Pepsin immunoassay was 100% sensitive and 89% specific for LPR. CONCLUSIONS: Detection of Pepsin in throat sputum by immunoassay appears to provide a sensitive, noninvasive method to detect LPR.
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Pepsin and carbonic anhydrase isoenzyme iii as diagnostic markers for laryngopharyngeal reflux disease
Laryngoscope, 2004Co-Authors: Nikki Johnston, Peter W Dettmar, Mark O Lively, John Knight, Jamie A KoufmanAbstract:Objectives/Hypothesis: The objective was to investigate the potential use of Pepsin and carbonic anhydrase isoenzyme III (CA-III) as diagnostic markers for laryngopharyngeal reflux disease. Study Design: Prospective cell biological investigation was conducted of laryngeal biopsy specimens taken from 9 patients with laryngopharyngeal reflux disease and 12 normal control subjects using antibodies specific for human Pepsin (produced in the authors' laboratory within the Department of Otolaryngology at Wake Forest University Health Sciences, Winston-Salem, NC) and CA-III. Methods: Laryngeal biopsy specimens were frozen in liquid nitrogen for Western blot analysis and fixed in formalin for Pepsin immunohistochemical study. Specimens between two groups (patients with laryngopharyngeal reflux disease and control subjects) were compared for the presence of Pepsin. Further analyses investigated the correlation between Pepsin, CA-III depletion, and pH testing data. Results: Analysis revealed that the level of Pepsin was significantly different between the two groups (P <.001). Secondary analyses demonstrated that presence of Pepsin correlated with CA-III depletion in the laryngeal vocal fold and ventricle (P <.001) and with pH testing data in individuals with laryngopharyngeal reflux disease. Conclusion: Pepsin was detected in 8 of 9 patients with laryngopharyngeal reflux disease, but not in normal control subjects (0 of 12). The presence of Pepsin was associated with CA-III depletion in the laryngeal vocal fold and ventricle. Given the correlation between laryngopharyngeal reflux disease and CA-III depletion, it is highly plausible that CA-III depletion, as a result of Pepsin exposure during laryngopharyngeal reflux, predisposes laryngeal mucosa to reflux-related inflammatory damage.
Mark O Lively - One of the best experts on this subject based on the ideXlab platform.
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Pepsin in saliva as a biomarker for oropharyngeal reflux compared with 24 hour esophageal impedance ph monitoring in pediatric patients
Neurogastroenterology and Motility, 2017Co-Authors: John E Fortunato, Ralph B Dagostino, Mark O LivelyAbstract:Background Pepsin in saliva is a proposed biomarker for oropharyngeal reflux. Pepsin may be prevalent in saliva from subjects with gastro-esophageal reflux and may correlate with proximal reflux by intraluminal impedance/pH monitoring (MII/pH). Methods Patients (3 days to 17.6 years, n=90) undergoing 24-hour MII/pH monitoring and asymptomatic controls (2 months to 13.7 years, n=43) were included. Salivary Pepsin was determined using a Pepsin enzyme-linked immunosorbent assay. Eight saliva samples were collected from patients undergoing 24-hr MII/pH: (i) before catheter placement, (ii) before and 30 minutes after each of three meals, and (iii) upon awakening. One sample was collected from each control. Key Results In MII/pH subjects, 85.6% (77/90) had at least one Pepsin-positive sample compared with 9.3% (4/43) in controls. The range of Pepsin observed in individual subjects varied widely over 24 hours. The average Pepsin concentration in all samples obtained within 2 hours following the most recent reflux event was 30.7±135 ng/mL, decreasing to 16.5±39.1 ng/mL in samples collected more than 2 hours later. The frequency of Pepsin-positive samples correlated significantly with symptom index (rS=0.332, P=.0014), proximal (rS=0.340, P=.0010), and distal (rS=0.272, P=.0095) MII events. Conclusions & Inferences Concentration of salivary Pepsin may not be an accurate measure of severity of reflux because of the wide range observed in individuals over 24 hours. Saliva samples must be obtained soon after a reflux event. Defining a regimen for optimal saliva collection may help to achieve the goal of using salivary Pepsin as a biomarker for oropharyngeal reflux. Clinical Trial registry NCT01091805.
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activity stability of human Pepsin implications for reflux attributed laryngeal disease
Laryngoscope, 2007Co-Authors: Nikki Johnston, Peter W Dettmar, Bimjhana Bishwokarma, Mark O Lively, Jamie A KoufmanAbstract:OBJECTIVES/HYPOTHESIS: Exposure of laryngeal epithelia to Pepsin during extra-esophageal reflux causes depletion of laryngeal protective proteins, carbonic anhydrase isoenzyme III (CAIII), and squamous epithelial stress protein Sep70. The first objective of this study was to determine whether Pepsin has to be enzymatically active to deplete these proteins. The second objective was to investigate the effect of pH on the activity and stability of human Pepsin 3b under conditions that might be found in the human esophagus and larynx. STUDY DESIGN: Prospective translational research study. METHODS: An established porcine in vitro model was used to examine the effect of active/inactive Pepsin on laryngeal CAIII and Sep70 protein levels. The activity and stability of Pepsin was determined by kinetic assay, measuring the rate of hydrolysis of a synthetic Pepsin-specific substrate after incubation at various pH values for increasing duration. RESULTS: Active Pepsin is required to deplete laryngeal CAIII and Sep70. Pepsin has maximum activity at pH 2.0 and is inactive at pH 6.5 or higher. Although Pepsin is inactive at pH 6.5 and above, it remains stable until pH 8.0 and can be reactivated when the pH is reduced. Pepsin is stable for at least 24 hours at pH 7.0, 37 degrees C and retains 79% +/- 11% of its original activity after re-acidification at pH 3.0. CONCLUSIONS: Detectable levels of Pepsin remain in laryngeal epithelia after a reflux event. Pepsin bound there would be enzymatically inactive because the mean pH of the laryngopharynx is pH 6.8. Significantly, Pepsin could remain in a form that would be reactivated by a subsequent decrease in pH, such as would occur during an acidic reflux event or possibly after uptake into intracellular compartments of lower pH.
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sensitive Pepsin immunoassay for detection of laryngopharyngeal reflux
Laryngoscope, 2005Co-Authors: John Knight, Nikki Johnston, Peter W Dettmar, Mark O Lively, Jamie A KoufmanAbstract:OBJECTIVES/HYPOTHESIS: To determine whether measurement of Pepsin in throat sputum by immunoassay could be used as a sensitive and reliable method for detecting laryngopharyngeal reflux (LPR) compared with 24-hour double-probe (esophageal and pharyngeal) pH monitoring. STUDY DESIGN: Patients with clinical LPR undergoing pH monitoring provided throat sputum samples during the reflux-testing period for Pepsin measurement using enzyme-linked immunoadsorbent assay. RESULTS: Pepsin assay results from 63 throat sputum samples obtained from 23 study subjects were compared with their pH monitoring data. Twenty-two percent (14/63) of the sputum samples correlated the presence of Pepsin with LPR (pH < or = 4 at the pharyngeal probe), of which the median concentration of Pepsin was 0.18 microg/mL (range 0.003-22 microg/mL). Seventy-eight percent (49/63) of the samples unassociated with (pharyngeal) reflux contained no detectible Pepsin. Mean pH values for Pepsin-positive samples were significantly lower than negative samples at both esophageal probe (pH 2.2 vs. pH 5.0) (P < .01) and the pharyngeal probe (pH 4.4 vs. pH 5.8) (P < .01). When the Pepsin assay results were compared with the pharyngeal pH data for detecting reflux (events pH < or = 4), the Pepsin immunoassay was 100% sensitive and 89% specific for LPR. CONCLUSIONS: Detection of Pepsin in throat sputum by immunoassay appears to provide a sensitive, noninvasive method to detect LPR.
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Pepsin and carbonic anhydrase isoenzyme iii as diagnostic markers for laryngopharyngeal reflux disease
Laryngoscope, 2004Co-Authors: Nikki Johnston, Peter W Dettmar, Mark O Lively, John Knight, Jamie A KoufmanAbstract:Objectives/Hypothesis: The objective was to investigate the potential use of Pepsin and carbonic anhydrase isoenzyme III (CA-III) as diagnostic markers for laryngopharyngeal reflux disease. Study Design: Prospective cell biological investigation was conducted of laryngeal biopsy specimens taken from 9 patients with laryngopharyngeal reflux disease and 12 normal control subjects using antibodies specific for human Pepsin (produced in the authors' laboratory within the Department of Otolaryngology at Wake Forest University Health Sciences, Winston-Salem, NC) and CA-III. Methods: Laryngeal biopsy specimens were frozen in liquid nitrogen for Western blot analysis and fixed in formalin for Pepsin immunohistochemical study. Specimens between two groups (patients with laryngopharyngeal reflux disease and control subjects) were compared for the presence of Pepsin. Further analyses investigated the correlation between Pepsin, CA-III depletion, and pH testing data. Results: Analysis revealed that the level of Pepsin was significantly different between the two groups (P <.001). Secondary analyses demonstrated that presence of Pepsin correlated with CA-III depletion in the laryngeal vocal fold and ventricle (P <.001) and with pH testing data in individuals with laryngopharyngeal reflux disease. Conclusion: Pepsin was detected in 8 of 9 patients with laryngopharyngeal reflux disease, but not in normal control subjects (0 of 12). The presence of Pepsin was associated with CA-III depletion in the laryngeal vocal fold and ventricle. Given the correlation between laryngopharyngeal reflux disease and CA-III depletion, it is highly plausible that CA-III depletion, as a result of Pepsin exposure during laryngopharyngeal reflux, predisposes laryngeal mucosa to reflux-related inflammatory damage.
