The influence of strain-specific Helicobacter pylori and serum gastrin levels on development of colon adenocarcinoma

A1284 AGA ABSTRACTS

5864 CHANGE OF GASTRIC HISTOLOGYCAL FINDINGS AFTER ERADICATION OF HELICOBACTER PYLORI. Yoshiya Nishimura, Natsuko Tsuda, Masato Komori, Kentaro Shimizu, Shigemitsu Oka, Tomoki Michida, Akira Kaneko, Nobukazu Yuuki, Keiji Yamamoto, Kazuhei Kurosawa, Michio Kato, Masahiro Ikeda, Osaka National Hosp, Osaka, Japan. An increasing number of studies have reported an association between Helicobacter pylori (H pylori) infection and gastric cancer, linked through chronic gastritis and accompanying intestinal metaplasia. However, it is uncertain whether eradication of H pylori improves the histo-pathological change of chronic gastritis and whether it reduces the incidence of gastric cancer. There has been controversial reports regarding improvement of gastric mucosal inflammation after eradication of H pylori. Thus, this study aims to investigate if eradication of H pylori improves the extent of mocosal inflammation in chronic gastritis. Method: Endoscopically diagnosed H pylori-positive patients were eradicated with a proton-pump inhibitor, amoxicillin and clarithromycin. Diagnosis of infection was made when rapid urease test or culture is positive for H pylori or the organism is found histologically. Biopsy specimens were examined histologically and the extent of mucosal inflammation was scored based on the updated Sydney system. Histological findings after eradication were compared with those before eradication. Results: Ten patients infected with H pylori were treated for eradication and the treatment was successful in 9 patients. One month after eradication of H pylori, inflammatory infiltration on the gastric mucosa was reduced significantly in the patients in whom H pylori was successfully eradicated, but the extent of intestinal metaplasia was not histologically evident. [Conclusions] In atrophic gastritis, mucosal infiltration was improved early after eradication of H pylori, on the other hand, intestinal metaplasia was not changed in a month following eradication. 5865 IMPORTANCE OF GENETIC POLYMORPHISM OF S-MEPHE· NYTOIN·4'-HYDROXYLASE(CYP2CI9) IN ERADICATION OF

HELICOBACTER PYLORI. Tatsusige Nisijima, Yoriaki Endo, Shinichi Ota, Kenji Fujiwara, Saitama Med Sch, Irumagun Saitama, Japan; Shijinkai yosikawa hosp, Tokorozawa Saitama, Japan; Saitama Med Sch, Moroyama Irumagun, Japan. [Purpose] Proton pump Inhibitor(PPI) are metabolized by CYP2C 19 in the liver. Since there are individual differences in the activity of this enzyme, it is possible that the pharmacological action of PPI is enhanced in patients with low CPY2Cl9 activity. We evaluated the association between CYP2Cl9 mutations and the effects of eradication therapy. Subjects: The subjects consisted of 30 patients with peptic ulcer( 17 males and 13 females with a mean age of 54 years). Methods: Eradication therapy was performed with rabeprazole sodium (lOmg/day) Clarithromycin(400mg/day) during 14 days. Genotype and phenotype of CYP2C 19 were determined by PCR analysis of peripheral blood leukocytes. Results: In patients without CYP2Cl9 mutations, eradication was successful in 4 patients(eradication rate, 36.4%) but not in 7 . In patients with 1 mutation, eradication was successful in 9 patients(64.3%) but not in 5. On the other hand, eradication was successful in all 5 patients(lOO%) with 2 mutation, respectively(p<0.05). Conclusion: Measurement of genetic polymorphism of CYP2CI9 may be useful for predicting the effects of eradication therapy. 5866 l3C-UREA BREATH TEST (l3C·UBT) FOR VALIDATION OF SUCCESSFUL HELICOBACTER PYLORI ERADICATION. EVALUATION OF 1374 PATIENTS. Varon Niv, Galia Abuksis, Shuli Ben-Gur, Rivka Koren, Rabin Med Ctr, Petach-Tikva, Israel. Niv Y, Abuksis G, Ben-Gur S, Koren R. Helicobacter pylori Laboratory, Department of Gastroenterology, Beilinson Campus, Rabin Medical Center and Tel-Aviv University, Israel. Introduction: Serology is not recommended for validation ofH. pylori successful eradication since the decrease in IgG titer is not sensitive enough. Histology, culture and urease test are all invasive (endoscopy and biopsy are needed). Thus, l3C-UBT stays the test of choice, as a non-invasive, highly sensitive test. Aim: To study the potential predictors of successful H. pylori eradication. Methods: In 1999, 1374 patients (out of 5000) were referred to the Central H. pylori Laboratory of Kupat-Cholim Clalit for 13C-UBT, with the indication to validate the successful eradication of H. pylori. This laboratory serves 25 collection laboratories all over Israel. The test was performed with a mass spectrograph AP2003 UK, after swallowing 75mg of 13C-urea. The cut-off of 13CI12C, no -TO was 3.5. A questionnaire that included demographic data, indication for l3C-UBT, clinical picture and previous eradication trials, was completed and computed by the referring physician. Results: 359 patients (26%) had a positive test. Recurrent dyspeptic symptoms and a proven peptic disease were reported in 47% and 57% of patients in the positive group, and in 38% and 50% of patients in the negative group, respectively (p<0.05 for both parameters). A combination therapy of a proton-pump-inhibitor, clarithromycin and amoxycillin (PPI-CA) was used in 44% and 57% of the patients in the positive and negative groups, respectively (p < 0.01). Any combination that contained metronidazole was used in 56% and 43% of the patients in the positive and negative groups, respectively (p < 0.0l). Conclusion: Recurrent symptoms of known peptic disease may predict unsuccessful H. pylori eradication. The

GASTROENTEROLOGY Vol. 118, No.4

use of triple therapy containing PPI-CA without metronidazole therapy may improve H. pylori eradication rate. 5867 GASTRITIS SEVERITY, GASTRIC CANCER PRECURSORS AND HELICOBACTER PYLORI GENOTYPE. Cristina Nogueira, Ceu Figueiredo, Fatima Carneiro. Leen-Jan van Doorn, Juan C. Bravo, Luis E. Bravo, Bernardo Ruiz, Pelayo Correa, Univ of Porto, Porto, Portugal; Delft Diagnostic Lab. Delft, Netherlands; Univ del Valle, Cali, Colombia; LSU Med Ctr, New Orleans, LA. The manifestations of H. pylori infection differ substantially among individuals and populations. Host, environmental and bacterium-related factors are possible determinants of the different infection outcomes. Gastritis grading and H. pylori genotype were investigated in 168 volunteers from Narifio, Colombia. a region with very high gastric cancer rates. Gastritis was graded with standard visual analog scales in 4 antral biopsies. DNA was extracted from a fresh-frozen antral biopsy, and used to amplify cagA, vacA and iceA genes (multiplex and allele-specific PCR). Most participants (82-90%) were infected with vacA s l, ml and cagA positive strains. Ninety-six percent of cagA positive strains were vacA s l-positivie, and 93% of them were ml-positive. The iceA genotypes were distributed as follows: 30% iceA I, 44% iceA2, 24% mixed, and 2% negative. Compared with subjects infected with vacA s2, m2 and cagA negative strains, those infected with vacA s1, m I and cagA positive strains had significantly higher scores for: neutrophilic infiltration (2.2 vs. 1.6 P < 0.001); epithelial regeneration (1.8 vs. 1.0 p < 0.00l); epithelial damage (2.4 vs. 0.8 p < 0.001); atrophy (1.2 vs. 0.4 p < 0.001); and intestinal metaplasia (0.8 vs. 0.2 p < 0.0l). Subjects infected with vacA s1, m1 and cagA positive strains had also higher prevalence of intestinal metaplasia (77% vs. 31%) and dysplasia (19% vs. 8%). The abundance of H. pylori colonization and the lymphocytic infiltration were similar in the two groups. The type and severity of chronic gastritis was not significantly associated with the iceA genotype. In conclusion: in the high-risk population investigated, there is a high prevalence of vacA sl , ml and cagA positive H. pylori strains; compared with other strains, strains expressing this genotype are associated with more severe acute inflammatory damage, higher atrophy and intestinal metaplasia scores and higher prevalence of metaplasia and dysplasia. 5868 GASTRIC METAPLASIA IN THE DUODENUM EXHIBITS INCREASED INTERLEUKIN-8 ACTIVITY IN DUODENAL ULCER PATIENTS. Mitsuhiro Noshiro, Kazuo Kusugami, Akira Imada, Takafumi Ando, Kenji Ina, Yuji Nishio, Masahiro Ohsuga, Tomoyuki Tsuzuki, Masaaki Shimada, Kazuo Nobata, Haruo Yamaguchi, Hiroshi Kaneko, Nagoya Univ Sch of medicine. Nagoya, Japan; Aichi Med Univ, Nagoya, Japan. Background and Aims: Although elevated levels of interleukin (IL)-8 are known to be associated with infiltration of neutrophils in the gastric mucosa with Helicobacter pylori (H. pylori) infection, no study has investigated a relationship between local IL-8 levels and neutrophil infiltration in the duodenal mucosa of H. pylori-positive duodenal ulcer (DU) patients. Methods: Duodenal mucosal biopsies with and without gastric metaplasia (GM) were obtained from patients with DU (n=25) and controls (n=2l) using an endoscopic methylene blue (MB) staining method. Levels of IL-8 secreted in the organ cultures of biopsy specimens were measured by an enzyme-linked immunosorbent assay. Numbers of rnyeloperoxidase-positive neutrophils infiltrating the lamina propria were determined in immunohistochemically stained tissue sections. Results: Histological assessment showed that there was a strong correlation between the absence of endoscopic MB staining and the extent of GM. The levels of IL-8 in both duodenal and antral mucosal tissues were significantly higher in patients with H. pylori infection than in those without infection. In patients with DU, the duodenal mucosal tissues with GM (MB-unstained mucosa) exhibited significantly higher levels of IL-8 compared with those without GM (MB-stained mucosa) or the antral mucosa. The numbers of neutrophils showed similar variations among DU and control patients with a positive correlation with IL-8 activity. The levels of IL-8 and the numbers of neutrophils decreased after H. pylori eradication in both duodenal and antral mucosal tissues and these changes were more remarkable in the duodenal mucosal tissues with GM. Conclusions: Increased IL-8 activity in the duodenal mucosa with GM may be important for ulcerogenesis in H. pylori-positive DU patients. 5869 THE INFLUENCE OF STRAIN·SPECIFIC HELICOBACTER PY· LORI AND SERUM GASTRIN LEVELS ON DEVELOPMENT OF COLON ADENOCARCINOMA. Kairasp C. Noshirwani, Walter E. Smalley, John Delvalle, Guillermo I. Perez-Perez, Roy L. Hood, Richard M. Peek, Vanderbilt Univ Med Ctr, Nashville, TN; Veteran's Admin Med Ctr, Nashville, TN; Univ of Michigan-Ann Arbor. Ann Arbor, MI. Background: Reports in the literature suggest an association between Helicohacter pylori(ll. pylori) and colon cancer. Hypergastrinemia has also been implicated in the development of colonic neoplasia. A suggested hypothesis for this association is that elevated gastrin levels induced by H, pylori-related chronic gastritis lower the threshold for development of colorectal cancer. Since H. pylori cagA + strains induce more severe

April 2000

gastric inflammation, we investigated the possible association between H.

pylori strain-specific genotypes, gastrin levels and colon cancer. Methods: Phlebotomy was performed on patients presenting for colonoscopy with or without colon adenocarcinoma. H. pylori and CagA serology were determined by ELISA and gastrin (fmlml) by radioimmunoassay. Individuals with prior treatment for H. pylori infection were excluded. Results: Thirty three males with colon cancer and 43 age and sex matched controls had serological testing for H. pylori. Twenty three (70%) of all cancer patients and 37 (86%) of all controls had gastrin levels determined. 17/33 (53%) and 13/33 (39%) of colon cancer patients tested positive for H. pylori and CagA respectively. Of the controls 19143 (44%) and 13/33 (30%)tested positive for H. pylori and CagA respectively. Using chi-square testing there were no significant differences between colon cancer patients or controls in either H. pylori or cagA+ prevalence (p = 0.2917 and 0.404, respectively). There were also no significant differences in gastrin levels between controls (mean = 76 (95% CI 0-156) and colon cancer patients (mean = 75 (0 - 202); H. pylori +ve cancers (mean 140 (0-294)and H. pylori +ve controls (mean =28 (2-53); cagA+ cancers (mean = 185 (0-391)and cagA+ controls (mean = 28 (3-53). Conclusion: I) The prevalence of H. pylori or cagA + strains is not significantly different among colon cancer patients compared to controls. 2) Colon cancer patients infected with H. pylori cagA + strains do not demonstrate significant hypergastrinemia compared to controls.

5870 OPTIMAL GASTRIC BIOPSY LOCALIZATION IN HELICOBACTER PYLORI INFECTION. Thomas V. Nowak, St Joseph Med Centerl St Vincent Hosp, Kokomol Indianap, IN. Helicobacter pylori (HP) organisms are most commonly found in the antrum of infected individuals. However, distribution of the organism in the stomach may vary and biopsy of proximal and distal stomach has been recommended (Gut 36:12-16, 1995) but not followed in clinical practice. Both histologic examination of biopsy specimens and detection of urease activity show a 90-100% sensitivity and specificity in detecting HP infection. However, the relative efficacy of histology and urease activity in detecting infection in biopsy specimens from the proximal and distal stomach is unclear. Purpose: To determine the optimal gastric biopsy site and method of biopsy processing for HP infection. Methods: 113 patients referred for evaluation of upper GI symptoms underwent UGI endoscopy. Antral biopsies taken within a 2 em radius of the pylorus were submitted for histologic examination and urease activity. Similar proximal gastric biopsies were taken from a longitudinal fold along the greater curvature of the stomach within 3 cm of the squamocolumnar junction. Results: 26 patients showed HP infection when biopsies from both gastric sites were examined by both methods. Twenty-one (81 %) showed infection in the distal stomach, while 18 patients (70%) showed infection in the proximal stomach. Half the patients (14/26, or 54%) showed infection in both proximal and distal gastric sites. The infection was confined to the antrum in 8126 patients (31%) and to the proximal stomach in 4126 patients (15%). In the antrum histology was appreciably more sensitive than urease activity (81 % vs 46%, respectively) in detecting HP infection. In the proximal stomach histology was somewhat less sensitive than urease activity (42% vs 58%). When both gastric sites were considered together, histology appeared more sensitive (88% vs 58%) than urease activity in detecting HP infection. Summary: I. Proximal and distal stomach vary appreciably in the ability of histologic examination and urease activity to detect HP infection. Histologic examination is more sensitive in the antrum but not in the proximal stomach. 2. 15% of patients have evidence of infection confined to the proximal stomach and the infection would be overlooked if biopsies were taken from the antrum only. Conclusion: Biopsy of both proximal and distal stomach sites is recommended with specimens submitted for both histologic examination and determination of urease activity.

5871 DYSPEPSIA IN PRIMARY CARE: PROKINETIC THERAPY OR ACID SUPPRESSION? A RANDOMIZED CLINICAL TRIAL. Mattijs E. Nurnans, Ruut A. Melker, Arno W. Hoes, Niek J. Wit, Univ Med Or Utrecht, Utrecht, Netherlands; Univ Med Ctr, Utrecht, Netherlands. Background: While dyspepsia patients in primary care often receive empirical treatment with antisecretory drugs, a substantial part of them suffers from motility disturbances. It is unknown whether prokinetic therapy is more effective than antisecretory therapy in uninvestigated dyspepsia. Method: A randomized, double-blind trial comparing the effectiveness of four weeks of cisapride 10 mg bid with that of ranitidine 150 mg bid, with three months follow-up. Included patients had dyspeptic symptoms with a low likelihood of organic (ulcer, reflux, or malignant) disease, i.e. absence of alarm symptoms or a history of PUD or GERD. Treatment failure was defined as no response to treatment or a relapse of symptoms within the follow-up period. In addition, the effect on dyspepsia severity, response to treatment after 4 weeks, and time to relapse were studied. Results:For all randomized patients, the difference in symptom severity score after 4 weeks of treatment was 0.3 (95% CI -0.4 to 1.0); the incidence of overall treatment success after three months follow-up with cisapride was 122/249 (49.0%) and with ranitidine 107/247 (43.3%); risk difference 5.7% (95% CI -3.1 to 14.0). For patients responding to 4 weeks treatment, relapse-free time was 86 days in the cisapride group and 79 days in the ranitidine group (p=0.005). Conclusion.Prokinetic and antisecretoy therapies are equally

AGAA1285

effective in primary care patients with uninvestigated dyspeptic complaints, though relapse rates are lower in patients successfully treated with cisapride.

5872 HELICOBACTER PYLORI PROTECTS GASTRIC EPITHELIAL CELLS FROM ETHANOL INDUCED CELL INJURY. Angela Nunley, Robert L. Copeland, Duane T. Smoot, Howard Univ, Washington, DC. Background: H. pylori causes damage to gastric epithelial cells both in vivo and in vitro. Ethanol also produces deleterious effects indirectly by increasing gastric acid secretions, which may lead to formation of stomach ulcers and mucosal erythema. Ethanol and its metabolites, such as acetaldehyde, may directly injure gastric mucosal cells. The aim of this study was to determine if pre-exposure to H. pylori alters ethanol induced gastric epithelial cell cytotoxicity. Methods: Experiments were performed using AGS cells, along with cagA-positive and negative H. pylori strains. Nonlethal cytotoxicity was estimated by measuring release of lactate dehydrogenase (LDH) into the cell culture medium, using an assay from Promega Corp (Madison, WI). AGS cells were treated overnight with H. pylori followed by exposure to varying doses of ethanol for I, 3 and 6 hours. Results: The results are shown in the table which displays the release of LDH into culture media. Data are presented as a % of positive controls, where all cells were lysed (total cell death). Pre-treatment with H. pylori reduced cell injury when compared to cells exposed to ethanol alone. A direct dose response curve was generated with exposure of ethanol to gastric cells. Conclusions: H. pylori pre-treatments significantly reduced ethanol induced cytotoxicity at each time point. In vivo studies have shown that gastric alcohol dehydrogenase activity is significantly reduced in gastric tissue from person's infected with H. pylori. One possible explanation for the cytoprotection provided by H. pylori, is that this bacterium may directly reduce ADH activity in gastric epithelial cells decreasing formation of acetaldehyde, a toxic metabolite of ethanol. More studies are needed to determine if H. pylori may directly alter ADH acitivity in gastric mucosal cells.

LDH Release from AGS cells Exposed toEthanol wilh orwithout H. pylori H.pylori + Ethanol

Time 1hour 3hours 6hours

25mM

50mM

100mM

200mM

25mM

139 174' 22.1'

197' 41.7 254'

20.0' 331' 269'

17.1' 429' 39.5'

149 25.6' 365'

Ethanol alone 50mM 100mM 34.9' 42.0 36.6'

38.6' 463' 43.9'

200mM 54.5' 50.1' 601'

, =statistical significance (p< 0.05)

5873 HELICOBACTER PYLORI STOOL ANTIGEN (HPSA) TEST FOR THE DETECTION AND THE FOLLOW-UP OF HELICOBACTER PYLORI INFECTION. A PRELIMINARY REPORT. Monica Nuti, Barbara Orsini, Barbara Ottanelli, Giuseppe Ciancio, Francesco Iovi, M. Rosa Biagini, Elisabetta Surrenti, Calogero Surrenti, Gastroenterology Unit, Florence, Italy. BACKGROUND: Several tests are today available for diagnosing Helicobacter pylori (Hp)infection. AIMS: To evaluate the accuracy of a new enzyme immunoassay, HpSA (Meridian Diagnostic, Cincinnati, USA), for detection and follow-up of Hp infection in human stools compared to standardized techniques. METHODS: Stool specimens from 24 consecutive endoscoped patients (MIF: 10/14; age range 37-70 years, mean 55 years) were examined. Patients with previous eradication treatment, use of Hy-anragonists, proton pump inhibitors, or antibiotics in the last month were excluded. Antrum and corpus biopsy specimens were obtained for histology (Hematoxilin & Eosin and Giemsa stains)and rapid urease test (CLO test, Delta West PtyLtd, Bentley, Australia); l3C-Urea Breath Test 13 ( C-UBT)(Helicobacter Test INFAI, Bochum, Germany; l3C-urea 75 mg, cut-off 4 0 / 0 0 ) was also performed (To). Hp infection was established by the concordance of 2/3 positive tests. Hp+ve patients were followed up after two weeks (Tj) and six weeks (T z) stopping eradication treatment comparing HpSA with 13C-UBT. The cut-off for the test (HpSA), defined as optical density at 450 nrn, was 0.140. RESULTS: At the first diagnosis (To). of 13 Hp+ve patients by the prefined criteria, II were HpSA+ve (sensitivity 84.6%)and of II patients without Hp infection, II were HpSA-ve (specificity 100%). The test showed an accuracy.a positive predictive value.a negative predictive value of 91.7%, 100% and 84.6 %, respectively. For the eradicant treatment 3 Hp+ve patients resulted dropout. At two weeks after therapy (Tj), as preliminary data, we referred results on 7110 Hp+ve patients. All 7 patients eradicated and 1/7 resulted HpSA+ve (accuracy 85.7%). At six weeks (Tz).we showed data on 3/7 treated patients and an accuracy of 100% was reported, as preliminary data. CONCLUSIONS:These preliminary results show that: I) the new noninvasive test HpSA seems sufficiently accurate for detection of Hp infection at the first diagnosis; 2) less accurate for monitoring Hp determination after two weeks stopping eradicant treatment; 3)it becomes highly accurate and successful after therapy at six weeks stopping treatment.