Rapid metabolizer genotype of CYP2C19 is a risk factor of being refractory to proton pump inhibitor therapy for reflux esophagitis.

BACKGROUND: Proton pump inhibitors (PPIs) are mainly metabolized by cytochrome P450 2C19 (CYP2C19) and used as the first-line therapy for gastroesophageal reflux disease (GERD). However, while several studies have examined the influence of CYP2C19 polymorphism on GERD treatment with PPIs, most have had small sample sizes and were conducted in a single center. Here, we used meta-analysis to investigate whether or not the CYP2C19 rapid metabolizer (RM) genotype is a risk factor for GERD patients being refractory to PPI therapy. METHODS: PubMed and other electronic databases were systematically searched up to August 2014 using the following terms: "GERD and CYP2C19", "esophagitis and CYP2C19", and "non-erosive reflux disease and CYP2C19." Searches were limited to publications in English, and two investigators evaluated eligible studies and extracted data. RESULTS: The total efficacy rate of PPIs for GERD, including reflux esophagitis (RE) and non-erosive reflux disease, was 56.4% (95% confidence interval [CI]; 53.9-58.9%, 870/1543) in intention-to-treat analysis and 63.8% (95%CI; 61.3-66.2%, 950/1489) in per-protocol analysis. Efficacy rates varied significantly between CYP2C19 genotypes (intention-to-treat analysis: RMs, 52.2% [315/604]; intermediate metabolizers, 56.7% [298/526]; poor metabolizers [PMs], 61.3% [138/225]; P = 0.047). Among RE patients, CYP2C19 RMs had an increased risk of being refractory to PPI therapy compared with PMs (odds ratio: 1.661, 95% CI: 1.023-2.659, P = 0.040). CONCLUSIONS: The present meta-analysis demonstrates that CYP2C19 RMs with RE have an increased risk of being refractory to PPI therapy compared with PMs. Individualized dosing regimen with PPIs based on CYP2C19 genotype might be a valid therapeutic strategy for overcoming insufficient gastric acid inhibition.

Inhibition of p38 MAPK activation attenuates esophageal mucosal damage in a chronic model of reflux esophagitis.

BACKGROUND: Reflux esophagitis (RE) is one of the common gastrointestinal diseases that are increasingly recognized as a significant health problem. This study was designed to investigate the role of p38 mitogen-activated protein kinase (MAPK) in experimental chronic RE model of rats. METHODS: Chronic acid RE rats were induced by fundus ligation and partial obstruction of the pylorus and treated with SB203580 (a p38 MAPK inhibitor, i.p., 1 mg/kg/day) for 14 days. KEY RESULTS: Immunohistochemical staining and Western blotting results revealed the activation of p38 MAPK signaling in the esophagus mucosa 14 days post injury. Through gross and histological assessment, we found that inhibition of p38 MAPK activation by SB203580 attenuated esophageal mucosal damage in RE rats. Inhibition of p38 MAPK activation in RE rats attenuated esophageal barrier dysfunction, through enhancing the expression of tight junction proteins and reducing the expression of matrix matalloproteinases-3 and -9. Inhibition of p38 MAPK activation in RE rats reduced CD68-positive cells in esophagus mucosa and mRNA levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß in esophagus and protein levels of TNF-α, IL-6, and IL-1ß in serum. In addition, we found that inhibition of p38 MAPK activation in RE rats suppressed protein expression of inducible nitric oxide synthase and reduced formation of nitric oxide (NO), 3-nitrotyrosin, and malondialdehyde in esophagus. CONCLUSIONS & INFERENCES: Inhibition of p38 MAPK activation attenuated esophageal mucosal damage in acid RE rats, possibly by modulating esophageal barrier function and regulating inflammatory cell recruitment, and the subsequent formation of cytokines, NO, and reactive oxygen species.

Enfermedades esofágicas: enfermedad por reflujo gastroesofágico, Barrett, acalasia y esofagitis eosinofílica / Esophageal diseases: GERD, Barrett, achalasia and eosinophilic esophagitis

En la Digestive Disease Week 2014 se han presentado importantes novedades en patología esofágica. A destacar, respecto de la enfermedad por reflujo gastroesofágico, la utilidad de la impedanciometría para el diagnóstico de la enfermedad por reflujo, o la eficacia de los inhibidores de la bomba de protones para el tratamiento del dolor torácico no coronario. Respecto del esófago de Barrett, que su prevalencia es idéntica en pacientes con y sin síntomas de reflujo, que el < 1 cm probablemente no precisa seguimiento y que en pacientes de edad y con Barrett largo, la endoscopia inicial pasa por alto hasta un 2% de lesiones significativas. Respecto de la acalasia, la miotomía quirúrgica no es superior a la dilatación endoscópica y podría ser menos efectiva que la miotomía endoscópica peroral (POEM). Respecto de la esofagitis eosinofílica, es importante tomar biopsias sistemáticamente en pacientes con disfagia, para no pasar por alto casos de esofagitis eosinofílica y que, en esta patología, la dilatación endoscópica rutinaria no solamente no parece útil para mejorar el curso de la enfermedad, sino que incluso podría empeorar la respuesta al tratamiento médico

At Digestive Disease Week (DDW) 2014, developments in esophageal disease were presented. Highlights include: the usefulness of impedancemetry to diagnose reflux disease, or the effectiveness of PPIs for treating non-cardiac chest pain. Concerning Barrett's esophagus, its prevalence is identical in patients with and without reflux symptoms, Barrett segments less than 1cm probably do not require follow-up, and in older patients with long-segment Barrett, initial endoscopies overlooked up to 2% of significant lesions. Regarding achalasia, surgical myotomy is no more effective than endoscopic dilation and may even be less effective than peroral endoscopic myotomy (POEM). In terms of eosinophilic esophagitis, it is important to systematically take biopsies in patients with dysphagia so that cases of eosinophilic esophagitis are not overlooked. In addition, for this condition, routine endoscopic dilations not only do not seem useful in improving the course of the disease, but could also worsen the response to medical treatment

Increased immunoreactivity of cathepsins in the rat esophagus under chronic acid reflux esophagitis.

We have designed a stable rat chronic acid reflux esophagitis (RE) model. In gastrointestinal lesions, several lysosomal cathepsins are known to participate in epithelial permeability in cell-cell connections, such as tight junctions in ulcerative colitis. However, very few studies have focused on the distribution of cathepsins in the esophageal multilayer squamous epithelium. Therefore to clarify the role of cathepsins in RE, we investigated their immunohistological localization in the esophageal epithelium under normal conditions and after RE. Of the cathepsins examined (cathepsins B, C, D, F, H, L, S, and X), granular immunoreactivity for cathepsins B, C, D and L was observed in the control esophageal epithelia; although, their distribution differed depending on the enzyme examined. In the RE model, immunoreactivity of these cathepsins was increased in esophageal epithelial cells and activated macrophages. The immunoreactivity for cathepsins F, H, S and X was barely detectable in the control esophageal epithelium. However, in the RE model, we noticed a slight increase in the expression of cathepsins H and X in the epithelial cells. Furthermore, activated macrophages of the RE model possessed intense immunoreactivity for these cathepsins, which may have been related to esophageal inflammatory mechanisms.

The activities of acid DNase and 5'nucleotidase in erosive reflux esophagitis and Barrett's epithelium.

BACKGROUND/AIMS: The study examines the relationship between activity of acid DNase and 5'nucleotidase (5'NT) and histological changes in reflux esophagitis. METHODOLOGY: Thirty-three patients were examined, 15 of whom with mild esophagitis, 12 with severe esophagitis and 6 with Barrett's epithelium. Patients were classified into 3 groups, according to Ismail-Beigi histological criteria: mild esophagitis group (ME); severe esophagitis group (SE); Barrett's esophagitis group (BE). DNase and 5'NT levels were measured biochemically both in healthy and injured tissue samples. RESULTS: Difference of acid DNase and 5'NT activity in healthy tissue versus injured tissue samples was the lowest in ME group: 0.55±4.47 U/g for acid DNase and 11.56±37.11 U/g for 5'NT, the difference increased to 4.43±1.64 U/g for acid DNase and 105.57±54.11 U/g for 5'NT in the SE group, while 6.07±2.92 U/g for acid DNase and 109.83±14.02 U/g for 5'NT as the highest levels were measured in the BE group. Difference in BE group is statistically significantly higher (p <0.05) compared to the ME group, confirmed by ANOVA with Dunnett's post hoc test. CONCLUSIONS: The study shows significant decrease of apotosis level that is detectable even before metaplasia was morphologically defined.

CYP2C19 genotypes determine the efficacy of on-demand therapy of pantoprazole for reflux esophagitis as Los-Angeles grades C and D.

BACKGROUNDS AND AIM: The present study determined whether the genotypes of S-mephenytoin 4'-hydroxylase (CYP2C19) could serve as an indicator to assess the success of long-term on-demand therapy (ODT) with pantoprazole for the patients with severe reflux esophagitis as Los Angles grade C or D (RE-CD). METHODS: A total of 240 patients with RE-CD were prospectively enrolled to receive continuous pantoprazole, 40 mg daily for 6 months. The patients, who achieved complete healing and were free from acid reflux-related symptoms during follow up, were included to receive ODT with a 40 mg pantoprazole tablet up to 1 year. Each patient was followed to assess the monthly tablet number of 40 mg pantoprazole and the cumulative rate of failure of ODT. The CYP2C19 genotype of each included patient was defined as homologous extensive metabolizer (HomoEM), heterologous extensive metabolizer (HeteroEM), and poor metabolizer (PM). RESULTS: Two-hundred patients were included to receive ODT, including 51 as HomoEM, 108 as HeteroEM, and 41 as PM. There were no differences in demographic and endoscopic features among patients with different CYP2C19 genotypes (P > 0.05). The 1-year cumulative failure rate of ODT was significantly higher in HomoEM than in HeteroEM and PM (P < 0.05, by log-rank test). For those with successful ODT during the 1-year follow up, the mean monthly tablet number of pantoprazole was lower in PM than in HeteroEM and HomoEM (11.5 vs 16.3 and 18.6, P < 0.05). CONCLUSION: For RE-CD with complete healing after continuous pantoprazole, the successful shift to ODT is determined by the CYP2C19 genotypes of the patients.

Gastroduodenal reflux induces group IIa secretory phospholipase A(2) expression and activity in murine esophagus.

Exposure of esophageal epithelium to gastric and duodenal contents results in the histologic changes of hyperproliferation and mucosal thickening. We have previously shown that presence of secretory phospholipase A(2) (sPLA(2)) is necessary to produce these histologic changes in a murine model of gastroduodenal reflux. We sought to determine the influence of gastroduodenal reflux (GDR) on sPLA(2) protein and mRNA levels as well as enzyme activity in esophageal tissue. BALB/c (sPLA(2)(+/+)) mice (n= 28) underwent side-to-side surgical anastomosis of the first portion of the duodenum and GE junction (DGEA) resulting in continuous exposure of esophageal mucosa to mixed gastric and duodenal contents. Sham control mice (n= 14) underwent laparotomy, esophagotomy and closure. Real-time RT PCR was used to quantitate the influence of GDR on group IIa sPLA(2) expression. Immunofluorescent staining was quantitated by digital microscopy using a specific antibody to identify and locate sPLA(2) protein. A colorimetric assay was used to quantify total sPLA(2) activity after standardization of protein levels. Statistical analysis was conducted using Student's t-test. Group IIa sPLA(2) mRNA and protein levels were increased at 4 and 8 weeks compared with sham controls. This increase occurred in a time-dependent manner and correlated with esophageal mucosal thickness. Furthermore, sPLA(2) enzyme activity was increased significantly at 4 and 8 weeks compared with untreated controls. The expression of group IIa sPLA(2) as well as sPLA(2) activity is induced by GDR. This novel finding indicates that sPLA(2) may play a role in the development of the histologic changes produced by GDR in esophageal mucosa.

[The indices of pro- and antioxidant state of the gastro-esophageal junction tissues in experimental gastroesophageal reflux disease].

Experimental investigation on studying of pro- and antioxidant state in esophageal tissues was performed. It was established, that accumulation of products of the proteins and lipids oxidation during inflammatory process course coincides with significant lowering of the antioxidant enzymes activity. The data obtained trusts the various diagnostic significance of diienic conjugates and malonic dialdehyde (MDA) levels. The increase of MDA concentration as well as of products of the oxidational modifications proteins, owing basic character, was revealed as a typical biochemical marker of acid-peptic injury of esophageal tissues.

Cyclooxygenase-2 and inducible nitric oxide synthase gene polymorphisms and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma.

The incidence of esophageal adenocarcinoma has increased in recent years, and Barrett's esophagus is a recognized risk factor. Gastroesophageal reflux of acid and/or bile is linked to these conditions and to reflux esophagitis. Inflammatory disorders can lead to carcinogenesis through activation of "prosurvival genes," including cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Increased expression of these enzymes has been found in esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Polymorphic variants in COX-2 and iNOS genes may be modifiers of risk of these conditions. In a population-based case-control study, we examined associations of the COX-2 8473 T>C and iNOS Ser(608) Leu (C>T) polymorphisms with risk of esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Genomic DNA was extracted from blood samples collected from cases of esophageal adenocarcinoma (n = 210), Barrett's esophagus (n = 212), and reflux esophagitis (n = 230) and normal population controls frequency matched for age and sex (n = 248). Polymorphisms were genotyped using TaqMan allelic discrimination assays. Odds ratios and 95% confidence intervals were obtained from logistic regression models adjusted for potential confounding factors. The presence of at least one COX-2 8473 C allele was associated with a significantly increased risk of esophageal adenocarcinoma (adjusted odds ratio, 1.58; 95% confidence interval, 1.04-2.40). There was no significant association between this polymorphism and risk of Barrett's esophagus or reflux esophagitis or between the iNOS Ser 608 Leu polymorphism and risk of these esophageal conditions. Our study suggests that the COX-2 8473 C allele is a potential genetic marker for susceptibility to esophageal adenocarcinoma.

Polymorphisms of glutathione S-transferase M1, T1 and P1 in patients with reflux esophagitis and Barrett's esophagus.

Reflux esophagitis (RE) and Barrett's esophagus (BE) belong to the most common esophageal complications of gastroesophageal reflux disease. Glutathione S-transferase (GST) enzymes play an important role in cellular protection against oxidative stress and toxic foreign chemicals. Therefore, we investigated the hypothesis that polymorphisms in genes for these detoxifying enzymes could influence susceptibility to RE and BE. GSTM1, GSTT1 and GSTP1 loci were analyzed by PCR-based methods in 64 patients with RE (and an additional group of 22 subjects with BE as the fourth grade of esophagitis) and 173 unrelated controls. There were no significant differences in the distributions of GSTM1 and GSTT1 genotypes between the controls and patients with RE or BE. Similarly, frequencies of GSTP1 alleles were non-significantly different between the control and RE groups. However, GSTP1 B allele carriers were more frequent among the patients with BE compared to those in the reflux esophagitis group (P=0.04, OR=2.10, 95% CI 0.99-4.44) and most significantly when compared to the controls (P=0.0067, Pcorr<0.05, OR=2.56, 95%CI 1.30-5.05). Although the GSTM1 and GSTT1 genes did not show any relationship with reflux disease, the GSTP1 gene might be one of the risk factors associated with susceptibility to RE, especially to BE.

Roles of cyclooxygenase 2 and microsomal prostaglandin E synthase 1 in rat acid reflux oesophagitis.

BACKGROUND: Although prostaglandin E2 (PGE2), cyclooxygenase 2 (COX-2), and microsomal prostaglandin E synthase 1 (mPGES-1) are known to play a role in various inflammatory events, their roles in the pathogenesis of gastro-oesophageal reflux disease are not known. AIMS: We examined the dynamics of COX-1, COX-2, mPGES-1, mPGES-2, cytosolic PGES (cPGES), and PGE2 synthetic activity in rat acid reflux oesophagitis and the effects of COX-2 inhibitors on the severity of oesophagitis. METHODS: Acid reflux oesophagitis was induced by ligating the transitional region between the forestomach and the glandular portion and wrapping the duodenum near the pylorus. Rats were killed on day 3 (acute phase) or day 21 (chronic phase) after induction of oesophagitis. RESULTS: Expression of COX-2 and mPGES-1 was markedly increased in oesophagitis while modest changes in COX-1, cPGES, and mPGES-2 expression were observed. COX-2 and mPGES-1 were colocalised in epithelial cells of the basal layer, as well as inflammatory and mesenchymal cells in the lamina propria and submucosa. COX-2 inhibitors significantly reduced the severity of chronic oesophagitis but did not affect acute oesophageal lesions. COX-2 inhibitors significantly inhibited the increase in PGE2 synthesis in oesophageal lesions on both days 3 and 21. Epithelial proliferation was significantly increased in the basal layer on day 21. Inflammatory cells and epithelial cells of the basal layer exhibited reactions for EP4 in oesophagitis. CONCLUSION: PGE2 derived from COX-2 and mPGES-1 plays a significant role in the pathogenesis of chronic acid reflux oesophagitis, and possibly in basal hyperplasia and persistent inflammatory cell infiltration.

Pepsin and carbonic anhydrase isoenzyme III as diagnostic markers for laryngopharyngeal reflux disease.

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.

The metabolic marker tumour pyruvate kinase type M2 (tumour M2-PK) shows increased expression along the metaplasia-dysplasia-adenocarcinoma sequence in Barrett's oesophagus.

BACKGROUND: Proliferating and tumour cells express the glycolytic isoenzyme, pyruvate kinase type M2 (M2-PK). In tumours cells, M2-PK usually exists in dimeric form (tumour M2-PK), causing the accumulation of glycolytic phosphometabolites, which allows cells to invade areas with low oxygen and glucose concentrations. AIMS: To investigate the expression of tumour M2-PK during the metaplasia-dysplasia-adenocarcinoma sequence of Barrett's oesophagus, and to assess the prognostic usefulness of tumour M2-PK in oesophageal cancer. MATERIALS/METHODS: One hundred and ninety cases selected from the histopathology archives as follows: 17 reflux oesophagitis, 37 Barrett's oesophagus, 21 high grade dysplasia, 112 adenocarcinomas, and three control tumours. Sections were stained immunohistochemically with antibody to tumour M2-PK. RESULTS: Tumour M2-PK was expressed in all cases, and increased cytoplasmic expression was seen with progression along the metaplasia-dysplasia-adenocarcinoma sequence. All cases of adenocarcinoma showed 100% staining so that tumour M2-PK was not a useful prognostic marker. CONCLUSIONS: Tumour M2-PK is not a specific marker of Barrett's adenocarcinoma, but may be important as a marker of transformed and highly proliferating clones during progression along the metaplasia-dysplasia-adenocarcinoma sequence.

[Changes in microcirculation of esophageal mucosa during acute experimental reflux. Pathogenic role of the biliary component]. / A nyelócsó nyálkahártya mikrokeringési változásai akut kísérletes reflux alatt--az epés komponens kóroki szerepe.

UNLABELLED: Our aims were to examine microcirculation during experimental reflux esophagitis in dogs. We compared the effects of microcirculation of the mucosa to 3-hr exposure with acid, mixed acid and bile, we measured the changes in constitutive and inducible nitric oxide synthase activity (cNOS and iNOS). METHODS: The microcirculation of the upper esophagus was investigated by intravital videomicroscopy. The functional capillary density (FCD), relative vessel area (RVA) and red blood cell velocity (RBCV) were measured. Mucosal barrier integrity was examined by vascular and epithelial permeability indices. Myeloperoxidase (MPO) enzyme activity, cNOS, iNOS activities and microscopic damage were examined in biopsies. RESULTS: The vascular permeability index, the RBCV and the RVA increased significantly in the treated groups, the FCD significantly decreased after acid exposure. The MPO and iNOS activities were significantly elevated in all treated groups. The cNOS activity did not change after exposure to acid + bile or acid, but significantly decreased after sole bile treatment. Severe mucosal damage was observed after bile exposure. CONCLUSION: Bile induced characteristic microcirculatory changes during experimental reflux esophagitis. Tissue damage and leukocyte infiltration could be exacerbated by bile-induced cNOS inhibition.

Telomerase activity and expression of human telomerase catalytic subunit gene in esophageal tissues.

BACKGROUND: Telomerase, the ribonucleoprotein enzyme that synthesizes telomeric DNA, is thought to be necessary for cellular immortality and carcinogenesis. Telomerase activity is associated with the majority of malignant human cancers. The mRNA that encodes the telomerase catalytic subunit (human telomerase repeat transcriptase; hTERT) has recently been identified, and the expression of the hTERT gene is thought to regulate the activation of telomerase. However, the expression of hTERT mRNA in esophageal tissues has not been reported. We investigated hTERT gene expression in cancerous and noncancerous esophageal tissues, and determined the relationship between hTERT mRNA expression and telomerase activity. METHODS: Tissues from esophageal carcinomas in 14 patients, reflux esophagitis in 12 patients, esophageal acanthosis in 2 patients, esophageal papilloma in 1 patient, radiation esophagitis in 1 patient, and normal esophageal epithelium in 11 patients (including 3 specimens of normal epithelium from patients with esophageal carcinoma) were examined. All specimens were taken endoscopically. hTERT gene expression was investigated using reverse transcription-polymerase chain reaction (RT-PCR). Quantitative analysis of telomerase activity was analyzed by fluorescence telomeric repeat amplification protocol (F-TRAP) assay. RESULTS: Thirteen of the 14 (93%) esophageal carcinoma specimens expressed hTERT mRNA and revealed detectable telomerase activity. Noncancerous esophageal lesions had not only hTERT mRNA expression with a high frequency (14 of 16 cases; 88%) but also detectable telomerase activity (12 of 13 cases; 92%). Normal esophageal epithelium also highly expressed hTERT mRNA (10 of 11 cases; 91%) and revealed detectable telomerase activity (all 9 cases; 100%). In 32 of the 35 specimens analyzed for both hTERT mRNA and telomerase activity (91%), the expression of hTERT mRNA was consistent with detectable telomerase activity. CONCLUSIONS: The expression of hTERT mRNA was detected not only in cancerous but also in noncancerous esophageal tissues at a high frequency. This result was different from that reported for other gastrointestinal epithelium. Moreover, telomerase activity in esophageal carcinoma was significantly stronger than that in reflux esophagitis and normal epithelium. In addition, there was a strong relation ship between the detection of telomerase activity and the expression of hTERT mRNA in cancerous and noncancerous esophageal tissues. Thus, the qualitative analysis of hTERT mRNA expression may not be useful as a biomarker of carcinoma in esophageal tissues. Nevertheless, the quantitative analysis of telomerase activity may be somewhat useful.

Assessment of non-acid esophageal reflux: comparison between long-term reflux aspiration test and fiberoptic bilirubin monitoring.

Reflux esophagitis may result from the action of both acid and non-acid agents. The aim of this study was to test a new system able to measure the quantity of the bilirubin contained in the esophageal lumen. The analysis of esophageal reflux composition was conducted in two phases. In the first bile and pancreatic enzyme, concentration of 136 fluid samples obtained with ambulatory esophageal long-term reflux aspiration test were measured. For the second, the total bilirubin content of each sample was measured in vitro with a fiberoptic probe (Bilitec 2000, Synetics Medical Inc., Sweden). Studies were performed on 48 subjects: 43 patients with esophageal reflux and five healthy volunteers. The results of both techniques were then compared. Higher concentration of bile and pancreatic enzymes were found in esophageal fluid samples of patients with endoscopic esophagitis. Bile and pancreatic enzyme concentrations of esophageal fluid samples were higher in patients after gastrectomy compared to patients with intact stomachs. There was a significant correlation between the total bilirubin concentration of fluid specimens and the fiberoptic probe reading of bilirubin (r = 0.72, P < 0.001). The presence of bilirubin and bile acids within the esophageal refluxate can be determined reliably with continuous fiberoptic measurement. The correlation between total bilirubin content and the concentrations of pancreatic enzymes contained in the esophageal refluxate suggests that bilirubin is a good tracer for non-acid, duodenal or intestinal reflux in the esophagus.

Reflux esophagitis in humans is a free radical event.

UNLABELLED: In this study, we investigated the implication of oxygen-derived free radicals in reflux esophagitis of humans. For this purpose we assessed oxidative stress in distal esophageal biopsies of controls, patients with various grades of esophagitis, Barrett's esophagus with and without severe associated esophagitis and patients following Nissen fundoplication. The total amount of oxygen-derived free radicals was measured by chemiluminescence. Membrane damage caused by free radicals was assessed by analysis of lipid peroxidation. In addition, we measured esophageal mucosal tissue levels of the free radical scavenger superoxide dismutase. RESULTS: Chemiluminescence and lipid peroxidation increased with the grade of esophagitis and were highest in patients with Barrett's esophagus. Findings following Nissen fundoplication were similar to controls. Superoxide dismutase decreased as the grade of esophagitis increased being lowest in Barrett's patients with severe associated esophagitis. High superoxide dismutase levels were found in Barrett's mucosa with mild associated esophagitis. CONCLUSIONS: Reflux esophagitis is mediated by free radicals. Barrett's is a severe form of oxidative damage. Antireflux surgery prevents oxidative damage of the esophageal mucosa. Superoxide dismutase is consumed by esophageal damage. In some patients with Barrett's, high superoxide dismutase levels of the esophageal mucosa may prevent severe esophagitis.

Circadian variations in gastric acid and pepsin secretion and intragastric bile acid in patients with reflux esophagitis and in healthy controls.

OBJECTIVES: Duodenogastric reflux is a physiological phenomenon in both fasting and postprandial state. Because this suggests that bile acids may reflux into the esophagus together with the acid in patients with reflux esophagitis, we investigated the circadian variations of acid and pepsin secretion and intragastric bile acid concentrations in 25 patients with reflux esophagitis and in 15 healthy controls. METHODS: Between-meal, nocturnal gastric and meal-stimulated acid and pepsin secretion and bile acid concentrations were measured by continuous gastric aspiration and intragastric titration. RESULTS: Bile acids were found in 85 and 59% of gastric samples (p < 0.05). Intragastric bile acid concentrations were 6-8-fold higher in esophagitis patients than controls during the day. Approximately 10% of gastric samples from reflux esophagitis patients had a pH greater than 7, and all contained more than 500 mumol/L bile acids. Bile acids and pepsin were simultaneously revealed in 98% of the gastric samples from patients with reflux esophagitis with pH less than 4. Mean daily acid output (meal excluded) averaged 3.5 +/- 0.1 in healthy subjects and 2.7 +/- 0.2 mmol/30 minutes in esophagitis patients (p < 0.05); meal-induced acid secretions were similar. Total (24-h) acid secretion averaged 192.3 +/- 12.4 and 162.4 +/- 10.5 mmol/24 h (p < 0.05). There were no differences in the daily pepsin output. CONCLUSIONS: Our data indicate that almost all "acid" gastroesophageal refluxes should be considered as "mixed" refluxes. Because bile acids are found in the stomach irrespective of whether the environment was acid or alkaline, pH-metry provides no useful information on the pattern of duodenogastric reflux into the esophagus. Variability in the composition of the gastro-esophageal refluxate may explain why the severity of esophageal lesions differs in patients with similar pattern of acid refluxes.

Ornithine decarboxylase (ODC) levels in children with reflux esophagitis.

Reflux esophagitis is a common disease in infants and can be diagnosed largely by esophageal biopsy. In adults, chronic esophagitis may lead to Barrett's esophagus, a premalignant condition for esophageal cancer development. Ornithine decarboxylase (ODC) is used as an early marker for colon cancer development. No data are available on the role of ODC in reflux esophagitis in the pediatric population. In this study we retrospectively analyzed ODC activity in esophageal biopsies of children who underwent upper endoscopy. According to the esophageal histology, patients were divided into three groups: normal mucosa, mild, and moderate/severe esophagitis. None of our patients had esophageal metaplasia or cancer. ODC level was significantly higher in the moderate/severe esophagitis group compared to mild and normal mucosa group. We conclude that ODC activity is directly proportional to the severity of the esophageal inflammation/regenerative process in children with reflux esophagitis.

Serum pepsinogens after interruption of long-term maintenance therapy with omeprazole in patients with reflux esophagitis.

Administration of omeprazole induces increases in serum concentrations of pepsinogens A and C. In 10 patients with reflux esophagitis who were on continuous maintenance treatment, the effect of cessation of omeprazole administration on serum pepsinogens was studied. Pepsinogens A and C were measured in serum samples on days 0, 1, 2, 4, 7, and 9 after treatment and the results were compared with the values available in eight patients at a time before omeprazole treatment. Serum pepsinogen A levels decreased gradually after cessation of omeprazole administration, and all values fell into the normal range after the seventh day of the study period, but were still higher than before therapy. Seven of 10 patients showed a decrease of pepsinogen C after nine days, but two patients had still increased levels at the end of the study period. The pepsinogen A:C ratio on the ninth day after cessation was significantly lower than on day 0 during omeprazole therapy. We conclude that long-term maintenance therapy with omeprazole induces significant increases in both serum pepsinogens. After cessation of omeprazole treatment, serum pepsinogens rapidly decrease in most patients, but continue to be higher before therapy for at least nine days.