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Esophagitis and Barrett's esophagus: Acid reflux, bile reflux, or both?
A224 AGA ABSTRACTS
1350 THE INCIDENCE OF REGRESSION AND NORMALIZATION OF INTESTINAL METAPLASIA IN A COHORT OF PATIENTS WITH EGJSIM, SSBE AND LSBE FOLLOWED OVER 3 YEARS. John David Horwhat, Darren Baroni, Corinne Maydonovitch, Eric M. Osgard, Eric J. Ormseth, Eugenia Rueda-Pedraza, Hyun Yang, William Hirota, Roy Kh Wong, Walter Reed Army Med Ctr, Washington, DC; Tripier Army Med Ctr, Honolulu, HI; Madigan Army Med Ctr, Tacoma, WA. Background: We previously reported the clinical characteristics and prevalence of Barrett's esophagus (BE) and EGJSIM in a cohort of 889 patients (Gastro 1999;116). Scant data concerning the natural history of SIM (EGJSIM, SSBE and LSBE) exists in a single cohort of patients. Aim: To determine the incidence ofregression (decrease in BE length) and mucosal normalization (loss of SIM) in a cohort of patients with EGJSIM, SSBE or LSBE followed for over 3 years. Methods: EGD performed, using standard forceps, biopsies taken in the antrum, body and cardia for H&E and in antrum and body for CLO. 4-quadrant biopsy taken from just below the SCJ in EGJSIM patients and at q2cm intervals in the BE segment. A biopsy was taken 1-2 em above the SCJ and H. pylori sera was drawn in all patients. Results: 1) Of 151 SIM patients originally reported, 42 (28%) were unavailable for followup due to: poor health (9), death (6), esophagectomylPDT (7), refusal (4), or inability to contact due to military relocation or change of address (14). Complete followup is currently available in 71 of the remaining 109 (65%). 2) Gender was similar in groups A=EGJSIM, n=30 and B=SSBE,n=31 (70% male) versus group C=LSBE, n=lO (100% male). Age and duration of followup (months f/uAlBIC=39±1142±2/41 ±1, p=0.498) were similar in all groups. Significant differences were noted in race (% Caucasian- AlBIC = 64/93/l 00, p=0.016); symptom duration (years heartburn- AlBIC = 11±2, 17±2, 23±5, p=0.020); and hiatal hernia (HH) size (AlBIC=0.9±0.3, 1.58±0.35, 2.90± 1.3 ern, p=O.OII). 3) PPI was used in 68%/76%/60% of groups AlBIC (group C, 30% fundoplication). 4) A regression in LSBE length (6.2±0.6 em baseline vs. 4.7±0.6 ern flu, p=0.022) was seen. 5) Overall, 47% normalized their SIM on followup. EGJSIM (21 of 30,70%) was significantly more likely to normalize than SSBE (12 of 31,39%) or LSBE (I of 10,10%) (p=0.004). 6) Normalization of SIM was associated with a shorter Barrett's length (1.1 ±0.6 vs 2.6±0.4 ern, p
1351 BILE SALTS-INDUCED PGEz RELEASE, PKCE AND COX-2 EXPRESSION, PARALLEL THE INCREASED CELLPROLIFERATION IN AN EX VIVO MODEL OF BARRETT'S ESOPHAGUS. Baljeet S. Kaur, M. Bishr Omary, George Triadafilopoulos, VA Palo Alto Health Care System and Stanford Univ, Palo Alto, CA. Background: Barrett's esophagus (BE) or specialized intestinal metaplasia is a complication of gastroesophageal reflux disease (GERD) and predisposes to dysplasia and esophageal adenocarcinoma. The role of duodenogastroesophageal reflux in GERD and BE remains controversial. Among refluxate constituents, bile salts induce cell proliferation in BE through a protein kinase C (PKCe)-dependent mechanism but they have no effect on cell proliferation of the squamous esophagus or duodenum (Gastroenterology 1999;116: A338). Bile salts also induce COX-2 expression, an effect that is inhibited by the selective COX-2 inhibitor, NS-398 (Gastroenterology 1999;116: A337). Aims: To evaluate the relationship between bile salt-induced cell proliferation, COX-2 expression, PKCe activation and PGE2 release. Methods:Using an organ culture system, endoscopic biopsies of normal esophagus, BE and normal duodenum were exposed to a I-hr pulse of a bile salt mixture (Na glycocholate and taurocholate, glycocholic acid, and taurochenodeoxycholate) with or without inhibitors of PKC (BIM) and COX-2 (NS-398) and then cultured at pH 7.4 for 24 hrs. Cell proliferation was measured by PCNA immunoblotting; expression of COX-2 and PKCe were determined by immunoblotting; PGE2 release in media was measured by Biotrak EIA assay. Results: Bile salt pulses enhanced cell proliferation in BE (2-3-fold), and stimulated PGE2 release in BE media (3-4-fold) starting as early as l-hr after exposure and without
GASTROENTEROLOGY Vol. 118, No.4
evidence of morphologic damage. This effect was parallel to COX-2 induction. PGE2 release was completely inhibited by NS-398 (5ILM). The bile salt induction of COX-2 expression was inhibited by both NS-398 and BIM (lILM). Conclusions: Our results suggest a strong correlation in the induction mechanism of both COX-2 and PKCe by bile salts. We suggest that direct or indirect PKC activation plays a role in COX-2 overexpression and PGE2 release, and may account for the proliferative effects of bile salts on BE. Disclosure: This study was supported by the Cancer Research Foundation of America.
1352 ESOPHAGITIS AND BARRETT'S ESOPHAGUS: ACID REFLUX, BILE REFLUX, OR BOTH? Gerardus H. Koek, Daniel Sifrim, Tony Lerut, Jozef Janssens, Jan F. Tack, Ctr for GI Research KU Leuven, Leuven, Belgium; Dept for Thoracic Surg KU Leuven, Leuven, Belgium. Recent studies, using ambulatory pH and esophageal bile reflux monitoring (Bilitec®), have shown that both acid reflux and duodeno-gastro-esophageal reflux (DGER) frequently occur in patients with gastro-esophageal reflux disease (GERD). Several studies reported a particularly high acid exposure as well as DGER exposure in patients with Barrett s esophagus. We observed that, with increasing severity of esophagitis, increasing exposure to both acid and DGER are found (Tack 1999). It is unknown whether increased DGER in higher grade lesions occurs secondarily to increased acid reflux, or whether this is an independent factor contributing to the development of esophageal lesions. The aim of the present study was to clarify the relationship between esophageal lesions, demographic factors, acid exposure and DGER. Methods: In 345 patients (184 men, age 47±15) evaluated for suspected GERD, upper g.i. endoscopy, and 24 hr pH and Bilitec® were performed. All drugs potentially affecting motility and acid secretion were discontinued at least one week prior to the study. In addition, demographic variables and smoking and alcohol consumption were registered. The % of time that the esophagus was exposed to acid and DGER was calculated. Data (mean±SEM) were analyzed by stepwise logistic regression, using acid and DGER exposure as continuous variables. P values of 0.05 and 0.1 were chosen as cutoff points to enter and exit the stepwise procedure. Odds ratios (OR) (95% confidence interval) were computed. Results: 56% of the patients had no esophagitis, 34% had grade 1-2 and 10% had grade 3-4, of which 69% had Barrett s esophagus. The presence of Barrett s esophagus was significantly associated with male sex (OR 4.4 (1.2-16.6), p
1353 DETECTION OF GENETIC MUTATIONS IN BARRETT'S ESOPHAGUS USING DENATURING HIGH PRESSURE LIQUID CHROMATOGRAPHY (DHPLC). Kausilia K. Krishnadathl, Ken Taniguchi, Navtej S. Buttar, Marlys A. Anderson, Lori S. Lutzke, Wanguo Liu, Chiping Qian, Ping Yang, David I. Smith, Kenneth K. Wang, Mayo Clin, Rochester, MN. The detection of mutations in the tumor supressor gene p53 have been frequently observed in Barrett s esophagus (BE). P53 mutation is considered a prognostic marker for malignant progression in BE. Aim: To determine the ability of DHPLC to detect p53 mutations in endoscopically removed biopsy specimens. Methods: DHPLC is a new method for detection of mutations and single nucleotide polymorphism (SNPs) analysis. In this study we applied DHPLC to detect p53 mutations in BE and BA. We first evaluated the sensitivity and specificity of this method in the analysis of 51 known p53 mutations identified in exons 5-8. Under a single set of conditions for each exon, 51151 samples carrying 36 unique mutations were correctly identified, giving a 100% sensitivity and specificity for detection of p53 mutation by DHPLC. DHPLC conditions for the remaining exons of the p53 gene (exons: 1, 2-3, 4, 9, 10 and l1)were then optimized. We screened for p53 mutations in endoscopically obtained biopsy specimens of 15 patients with BE. Seven without dysplasia and three with low, five with high-grade dysplasia, and 24 adenocarcinomas. All mutations detected by DHPLC were confirmed by direct sequencing. Results: P53 mutations were observed in 38% (9/24) of the adenocarcinomas, in 38% (3/8) of the dysplastic samples and in 0% of the non dysplastic samples. In three cases more than 1 mutation was found. In four cases the p53 mutations were found in exons 4 and 10. Besides mutations several polymorphisms were found in exons 2-3, 4 and 6. Conclusions: DHPLC is a sensitive and specific method for detection of p53 mutations in biopsy samples of Barrett s esophagus and esophageal adenocarcinoma. We also found that p53 mutations in BE frequently occur outside exons 5-9 of the p53 gene.
1350 THE INCIDENCE OF REGRESSION AND NORMALIZATION OF INTESTINAL METAPLASIA IN A COHORT OF PATIENTS WITH EGJSIM, SSBE AND LSBE FOLLOWED OVER 3 YEARS. John David Horwhat, Darren Baroni, Corinne Maydonovitch, Eric M. Osgard, Eric J. Ormseth, Eugenia Rueda-Pedraza, Hyun Yang, William Hirota, Roy Kh Wong, Walter Reed Army Med Ctr, Washington, DC; Tripier Army Med Ctr, Honolulu, HI; Madigan Army Med Ctr, Tacoma, WA. Background: We previously reported the clinical characteristics and prevalence of Barrett's esophagus (BE) and EGJSIM in a cohort of 889 patients (Gastro 1999;116). Scant data concerning the natural history of SIM (EGJSIM, SSBE and LSBE) exists in a single cohort of patients. Aim: To determine the incidence ofregression (decrease in BE length) and mucosal normalization (loss of SIM) in a cohort of patients with EGJSIM, SSBE or LSBE followed for over 3 years. Methods: EGD performed, using standard forceps, biopsies taken in the antrum, body and cardia for H&E and in antrum and body for CLO. 4-quadrant biopsy taken from just below the SCJ in EGJSIM patients and at q2cm intervals in the BE segment. A biopsy was taken 1-2 em above the SCJ and H. pylori sera was drawn in all patients. Results: 1) Of 151 SIM patients originally reported, 42 (28%) were unavailable for followup due to: poor health (9), death (6), esophagectomylPDT (7), refusal (4), or inability to contact due to military relocation or change of address (14). Complete followup is currently available in 71 of the remaining 109 (65%). 2) Gender was similar in groups A=EGJSIM, n=30 and B=SSBE,n=31 (70% male) versus group C=LSBE, n=lO (100% male). Age and duration of followup (months f/uAlBIC=39±1142±2/41 ±1, p=0.498) were similar in all groups. Significant differences were noted in race (% Caucasian- AlBIC = 64/93/l 00, p=0.016); symptom duration (years heartburn- AlBIC = 11±2, 17±2, 23±5, p=0.020); and hiatal hernia (HH) size (AlBIC=0.9±0.3, 1.58±0.35, 2.90± 1.3 ern, p=O.OII). 3) PPI was used in 68%/76%/60% of groups AlBIC (group C, 30% fundoplication). 4) A regression in LSBE length (6.2±0.6 em baseline vs. 4.7±0.6 ern flu, p=0.022) was seen. 5) Overall, 47% normalized their SIM on followup. EGJSIM (21 of 30,70%) was significantly more likely to normalize than SSBE (12 of 31,39%) or LSBE (I of 10,10%) (p=0.004). 6) Normalization of SIM was associated with a shorter Barrett's length (1.1 ±0.6 vs 2.6±0.4 ern, p
1351 BILE SALTS-INDUCED PGEz RELEASE, PKCE AND COX-2 EXPRESSION, PARALLEL THE INCREASED CELLPROLIFERATION IN AN EX VIVO MODEL OF BARRETT'S ESOPHAGUS. Baljeet S. Kaur, M. Bishr Omary, George Triadafilopoulos, VA Palo Alto Health Care System and Stanford Univ, Palo Alto, CA. Background: Barrett's esophagus (BE) or specialized intestinal metaplasia is a complication of gastroesophageal reflux disease (GERD) and predisposes to dysplasia and esophageal adenocarcinoma. The role of duodenogastroesophageal reflux in GERD and BE remains controversial. Among refluxate constituents, bile salts induce cell proliferation in BE through a protein kinase C (PKCe)-dependent mechanism but they have no effect on cell proliferation of the squamous esophagus or duodenum (Gastroenterology 1999;116: A338). Bile salts also induce COX-2 expression, an effect that is inhibited by the selective COX-2 inhibitor, NS-398 (Gastroenterology 1999;116: A337). Aims: To evaluate the relationship between bile salt-induced cell proliferation, COX-2 expression, PKCe activation and PGE2 release. Methods:Using an organ culture system, endoscopic biopsies of normal esophagus, BE and normal duodenum were exposed to a I-hr pulse of a bile salt mixture (Na glycocholate and taurocholate, glycocholic acid, and taurochenodeoxycholate) with or without inhibitors of PKC (BIM) and COX-2 (NS-398) and then cultured at pH 7.4 for 24 hrs. Cell proliferation was measured by PCNA immunoblotting; expression of COX-2 and PKCe were determined by immunoblotting; PGE2 release in media was measured by Biotrak EIA assay. Results: Bile salt pulses enhanced cell proliferation in BE (2-3-fold), and stimulated PGE2 release in BE media (3-4-fold) starting as early as l-hr after exposure and without
GASTROENTEROLOGY Vol. 118, No.4
evidence of morphologic damage. This effect was parallel to COX-2 induction. PGE2 release was completely inhibited by NS-398 (5ILM). The bile salt induction of COX-2 expression was inhibited by both NS-398 and BIM (lILM). Conclusions: Our results suggest a strong correlation in the induction mechanism of both COX-2 and PKCe by bile salts. We suggest that direct or indirect PKC activation plays a role in COX-2 overexpression and PGE2 release, and may account for the proliferative effects of bile salts on BE. Disclosure: This study was supported by the Cancer Research Foundation of America.
1352 ESOPHAGITIS AND BARRETT'S ESOPHAGUS: ACID REFLUX, BILE REFLUX, OR BOTH? Gerardus H. Koek, Daniel Sifrim, Tony Lerut, Jozef Janssens, Jan F. Tack, Ctr for GI Research KU Leuven, Leuven, Belgium; Dept for Thoracic Surg KU Leuven, Leuven, Belgium. Recent studies, using ambulatory pH and esophageal bile reflux monitoring (Bilitec®), have shown that both acid reflux and duodeno-gastro-esophageal reflux (DGER) frequently occur in patients with gastro-esophageal reflux disease (GERD). Several studies reported a particularly high acid exposure as well as DGER exposure in patients with Barrett s esophagus. We observed that, with increasing severity of esophagitis, increasing exposure to both acid and DGER are found (Tack 1999). It is unknown whether increased DGER in higher grade lesions occurs secondarily to increased acid reflux, or whether this is an independent factor contributing to the development of esophageal lesions. The aim of the present study was to clarify the relationship between esophageal lesions, demographic factors, acid exposure and DGER. Methods: In 345 patients (184 men, age 47±15) evaluated for suspected GERD, upper g.i. endoscopy, and 24 hr pH and Bilitec® were performed. All drugs potentially affecting motility and acid secretion were discontinued at least one week prior to the study. In addition, demographic variables and smoking and alcohol consumption were registered. The % of time that the esophagus was exposed to acid and DGER was calculated. Data (mean±SEM) were analyzed by stepwise logistic regression, using acid and DGER exposure as continuous variables. P values of 0.05 and 0.1 were chosen as cutoff points to enter and exit the stepwise procedure. Odds ratios (OR) (95% confidence interval) were computed. Results: 56% of the patients had no esophagitis, 34% had grade 1-2 and 10% had grade 3-4, of which 69% had Barrett s esophagus. The presence of Barrett s esophagus was significantly associated with male sex (OR 4.4 (1.2-16.6), p
1353 DETECTION OF GENETIC MUTATIONS IN BARRETT'S ESOPHAGUS USING DENATURING HIGH PRESSURE LIQUID CHROMATOGRAPHY (DHPLC). Kausilia K. Krishnadathl, Ken Taniguchi, Navtej S. Buttar, Marlys A. Anderson, Lori S. Lutzke, Wanguo Liu, Chiping Qian, Ping Yang, David I. Smith, Kenneth K. Wang, Mayo Clin, Rochester, MN. The detection of mutations in the tumor supressor gene p53 have been frequently observed in Barrett s esophagus (BE). P53 mutation is considered a prognostic marker for malignant progression in BE. Aim: To determine the ability of DHPLC to detect p53 mutations in endoscopically removed biopsy specimens. Methods: DHPLC is a new method for detection of mutations and single nucleotide polymorphism (SNPs) analysis. In this study we applied DHPLC to detect p53 mutations in BE and BA. We first evaluated the sensitivity and specificity of this method in the analysis of 51 known p53 mutations identified in exons 5-8. Under a single set of conditions for each exon, 51151 samples carrying 36 unique mutations were correctly identified, giving a 100% sensitivity and specificity for detection of p53 mutation by DHPLC. DHPLC conditions for the remaining exons of the p53 gene (exons: 1, 2-3, 4, 9, 10 and l1)were then optimized. We screened for p53 mutations in endoscopically obtained biopsy specimens of 15 patients with BE. Seven without dysplasia and three with low, five with high-grade dysplasia, and 24 adenocarcinomas. All mutations detected by DHPLC were confirmed by direct sequencing. Results: P53 mutations were observed in 38% (9/24) of the adenocarcinomas, in 38% (3/8) of the dysplastic samples and in 0% of the non dysplastic samples. In three cases more than 1 mutation was found. In four cases the p53 mutations were found in exons 4 and 10. Besides mutations several polymorphisms were found in exons 2-3, 4 and 6. Conclusions: DHPLC is a sensitive and specific method for detection of p53 mutations in biopsy samples of Barrett s esophagus and esophageal adenocarcinoma. We also found that p53 mutations in BE frequently occur outside exons 5-9 of the p53 gene.