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The effect of gastrin releasing peptide (GRP) infusions on the mRNAS encoding gastrin and somatostatin in patients with and without H. pylori infection
AIO0
AGA ABSTRACTS
GASTROENTEROLOGY, Vol. 108, No. 4
• THE MOLECULAR PATTERN OF HELICOBACTER PYLORI (Hp) RECURRENCE AFTER SUCCESSFUL ERADICATION TREATMENT IN DUODENAL ULCER (DU)PATIENTS,
• INTEROBSERVER VARIATION IN THE HISTOLOGIC EVALUATION OF HELICOBACTERpTI.ORIGASTRITIS. R.M. Crenta.
H.M.T. EI-Zirnaity,M.T. AI-Assi,H.M. Malaty, TJ. Karttun~ D.P. Graham, R.M. Huberman, D.Y. Graham. Depts. of Pathology and Medicine,VAMC and Baylor Collegeof Medicine, Houston, TX.
S. Georoocoulos1, C. Spiliadis1, A, Mentis2, P. Stabolos1, L. Tzouvelekis2, N, Skanda~ l ~ (1) Dept. of Gastroenterology,General Hospitalof Athens. (2) Dept. of Bacteriology;Hellenique Pasteur Institute;Athens, Greece.
Background: The histopathologieal detection of Helicobacter pylori in gastricbiopsy specimens is consideredthe gold standardforthe diagnosisof//. pylori infection. However, few studies have addressed the pathologists' reliability
Elimination of Hp is associated with decrease of DU recurrence rate. Nevertheless a small percentage of patients suffer a DU relapse related with recrudescence of Hp infection. The aim of this study was to investigate whether Hp isolation after successful eradication treatment represents a relapse of a temporarilysuppressed Hp strain or a.true reinfection. Patients-Methods: Fifty-five DU patients with Hp infection (42 men, 13 women/aged 28-74 average 49,0 years) examined 4-6 weeks after the completion of eradication therapy. 52 of them had successful Hp eradication documented by CLO-test, histology and culture. The latter patients included in a follow up program and had an endoscopywith biopsies at six months, yearly and whenever they had symptoms after completion of therapy. Ribotyping using a biotinyiatad eDNA probe- was used for the comparison of Hp strains isolated post-therapy~with the pre-treatmentones. Results: Forty patients (77,0%) had an endoscopic examination at six months, 35 (67,3%) completed one year follow-up and 11 (21,2%) two years follow up. Recrudescence of Hp infection was revealed in five patients (4 had a DU relapse). In four of them Hp isolated during the first post-treatmentyear (at 6,8,9 and 12 month) and in the fifth patient 18 months after the end of therapy. Ribotyping revealed a post-treatment Hp strain With the same ribopattern as the pre-treatment one in the former four patients while the latter patient herboured a post-treatmentHp strain with different ribopattern than his old one. Notably this "new" Hp strain had the same ribopettern with the Hp strain isolatedfrom patient's wife. Conclusions: Ribotyping provides strong evidence that the recurrence of Hp infection -which occurs in a small percentage of DU patients after apparently successfuleradicatlon treatment- usually represents regrowth of a temporarily suppressed Hp strain, although a late reinfection with a new strain is also possible.
to detect the organism and to assess the degree of the related inflammatory changes. Objectives: To determine the degree of agreement among 4 gastrointestinal pathologists in the semi-quantitative evaluation ofH. pylori infection and gastritis. Methods: Three slides from pre-determined areas of the stomach of 99 patients with and without H. pylori infection were stained with the Genta stain, coded and examined independently by four pathologists. For each specimen, a visual analog scale graded from 0 (absenVnormal) to 5 (maximal intensity) was used to score: 1) H. pylori; 2) neutrophils; and 3) atrophy. Data were analyzed using kappa statistics. Results: The best interobserver agreement (K = - 0.90) was present for the presence or absence ofH. pylori for all 3 biopsy sites. Agreement on the presence or absence of nentrophils was also excellent (K = 0.8) in antral biopsies and good (K = 0.67) in corpus biopsies. The agreement on semiquantitative scoring was markedly less. When the severity of the infection was evaluated by grouping the six categories into four (none, mild, moderate, and severe) results were improved but still not excellent. The poorest agreement was for atrophy (presence, absence, categories, or group categories): for this parameter K never exceeded 0.2. Conclusions: This group of pathologists had a high level of concordance (99%) on the diagnosis ofH. pylori infection in any particular patient and a very high index in the assessment of the intensity of infection. The agreement was less in the evaluation of active inflammation. When the evaluation concerned a looselydefmed feature such as atrophy, there was essentially no agreement. This study suggests the need for: 1) further assessmentsofpathologists' ability to provide reproducible diagnoses, and 2) better criteria for the diagnosis of "soft" histopathologic features (such as atrophy).
• H. PY1_ORIDECREASES EXPRESSION OF SOMATOSTATIN mRNA IN THE GASTRIC CORPUS AND ANTRUM OF NON-ULCER PATIENTS. Gibbons AH 1, Legon S2, Calam J~. Depts of Gastroenterology ~and Metabolic Medicine 2, Hammersmith Hospital, London, England. Introduction: It is proposed that H. pylori (Hp) causes duodenal ulcers (DU) by increasing gastric acid secretion. Results suggest that reflexes which normally inhibit acid secretion are defective because Hp gastritis decreases mucosal expression of somatostatin. We have reported that eradication of Hp from DU patients increases the expression of somatostatin mRNA inthe gastric antrum, but that sornatostatin mRNA in the corpus does not change. However a group inThe Netherlands have found less somatostatin peptide in the gastric corpus of non-ulcer patients infected with Hp, This might be due to a difference between expression of mRNA and peptide, or a difference between DU and non-ulcer patients. Therefore we compared the expression of somatostatin mRNA in the gastric corpus of non-ulcer patients with and without Hp infection. Methods: Biopsies were taken from the gastric corpus and antrum of 9 HP+ and 8 HP- dyspeptic patients for total RNA extraction and Northern blotting. A 32p labelled eDNA probe for somatostatin was used to detect the mRNA, the signals being quantified by phosphor imaging. GAPDH mRNA levels were measured to correct for differences in loading and transfer of RNA. Results: The expression of somatostatin mRNA was significantly decreased in the gastric corpus o f Hp+ patients (P < 0.003). Median corpus somatostatin mRNA was 0:08 (0.02 - 0.45) in Hp+ patients compared with 0.29 (0.17 - 0.48) in Hp- patients. The expression of somatostatin mRNA was also significantly decreased in the gastric antrum of Hp+ patients (P < 0.0009). Median antral somatostatin mRNA was 0.10 (0.04 - 0.4) in Hp+ patients compared with 0.39 (0.27 - 1.04) in Hp- patients. Somatostatin mRNA was significantly more abundant in the antrum than in the corpus of uninfected patients (P < 0.03) Conclusions: Expression of somatostatin mRNA is decreased in the gastric corpus of non-ulcer patients with Hp infection. This is consistent with the finding of decreased somatostatin peptide in the gastric corpus of these patients. We speculate that Hp affects corpus s0matostatin in non-ulcer patients but not DU patients because corpus gastritis tends to be marked in the former but minimal in the latter. Gastritis and decreased expression of somatostatin are present in the antrum of both groups. These results support the idea that in Hp infection it is the mucosal inflammation that affects expression of somatostatin.
•
THE EFFECT OF GASTRIN RELEASING PEPTIDE.(GRP) INFUSIONS ON THE mRNAS ENCODING GASTRIN AND SOMATOSTATIN IN PATIENTS WITH AND WITHOUT H. PYLORI INFECTION. Gibbons AH I, Legon S=, Calam Jl. Depts of Gastroenterology ~& Metabolic Medicine 2. Hammersmith Hospital; London, UK. Introduction: It has been proposed that H: pylori (Hp) causes peptic ulcers by increasing acid secretion. Hp-associated hypersecretion is most marked during infusion of GRP. To explore the underlying defect we compared the effect of GRP infusions on gastric expression of the mRNAs encoding gastrin and somatostatin between individuals with and without Hp infection. Methods: Dyspeptic non-ulcer patients, 9 Hp+ and 8Hp-, received a 3 hour intravenous infusion of GRP (14-27), 200 pmol/kg/h or vehicle alone on separate occasions. At the end of each infusion endoscopy was performed and biopsies taken from the gastric corpus and antrum for RNA extraction. Somatostatin and gastrin mRNA levels were determined on blots of total RNA using ~P-labelled eDNA probes for human somatostatin and gastrin and the signals quantified using phosphor imaging. GAPDH mRNA levels were measured to correct for RNA loading and transfer variations. Plasma gastrin was measured by radioimmunoassay. Results: Infusion of GRP produced a significant rise in antral gastrin mRNA in the Hp+ patients, but a significant fall in the Hp- group. Plasma gastrin rose in the Hp~- group but not appreciably in the Hp- patients. GRP stimulated a significant rise in antral somatostatin mRNA in the Hp+ group, but not in the Hp- group. Corpus somatostatin mRNA showed a similar trend but the rise in the infected group was not statistically significant. Hp+ HpPlasma gastrin: 295 (200-638)* 140 (123-157) Antrum: gastrin mRNA 127 (86-190)*" 81 (44-145)* Antrum: somatostatin mRNA 140 (85-190)* 93 (66-156) Corpus: somatostatin mRNA 167 (37-270) 66 (35-103) Leve/s post-GRP infusion are expressed as a percentage of values found after centre~ infusion (median and range); mRNA values were determined as peptide mRNA/GAPDH mRNA; * = P < 0.05 Conclusions: Gastrin-releasingpeptide (GRP) leads to a paradoxical inhibition of gastrin mRNA expression in Hp- individuals. The mechanism responsible is unknown but is altered in Hp+ people who show a significant rise in gastrin mRNA on GRP infusion. The mechanism might involve D-cells which are attenuated in Hp gastritis. Somatostatin mRNA only rose significantly in the antrum of Hp+ patients, This supports the idea that GRP stimulates antral D-cells by releasing gastrin,
AGA ABSTRACTS
GASTROENTEROLOGY, Vol. 108, No. 4
• THE MOLECULAR PATTERN OF HELICOBACTER PYLORI (Hp) RECURRENCE AFTER SUCCESSFUL ERADICATION TREATMENT IN DUODENAL ULCER (DU)PATIENTS,
• INTEROBSERVER VARIATION IN THE HISTOLOGIC EVALUATION OF HELICOBACTERpTI.ORIGASTRITIS. R.M. Crenta.
H.M.T. EI-Zirnaity,M.T. AI-Assi,H.M. Malaty, TJ. Karttun~ D.P. Graham, R.M. Huberman, D.Y. Graham. Depts. of Pathology and Medicine,VAMC and Baylor Collegeof Medicine, Houston, TX.
S. Georoocoulos1, C. Spiliadis1, A, Mentis2, P. Stabolos1, L. Tzouvelekis2, N, Skanda~ l ~ (1) Dept. of Gastroenterology,General Hospitalof Athens. (2) Dept. of Bacteriology;Hellenique Pasteur Institute;Athens, Greece.
Background: The histopathologieal detection of Helicobacter pylori in gastricbiopsy specimens is consideredthe gold standardforthe diagnosisof//. pylori infection. However, few studies have addressed the pathologists' reliability
Elimination of Hp is associated with decrease of DU recurrence rate. Nevertheless a small percentage of patients suffer a DU relapse related with recrudescence of Hp infection. The aim of this study was to investigate whether Hp isolation after successful eradication treatment represents a relapse of a temporarilysuppressed Hp strain or a.true reinfection. Patients-Methods: Fifty-five DU patients with Hp infection (42 men, 13 women/aged 28-74 average 49,0 years) examined 4-6 weeks after the completion of eradication therapy. 52 of them had successful Hp eradication documented by CLO-test, histology and culture. The latter patients included in a follow up program and had an endoscopywith biopsies at six months, yearly and whenever they had symptoms after completion of therapy. Ribotyping using a biotinyiatad eDNA probe- was used for the comparison of Hp strains isolated post-therapy~with the pre-treatmentones. Results: Forty patients (77,0%) had an endoscopic examination at six months, 35 (67,3%) completed one year follow-up and 11 (21,2%) two years follow up. Recrudescence of Hp infection was revealed in five patients (4 had a DU relapse). In four of them Hp isolated during the first post-treatmentyear (at 6,8,9 and 12 month) and in the fifth patient 18 months after the end of therapy. Ribotyping revealed a post-treatment Hp strain With the same ribopattern as the pre-treatment one in the former four patients while the latter patient herboured a post-treatmentHp strain with different ribopattern than his old one. Notably this "new" Hp strain had the same ribopettern with the Hp strain isolatedfrom patient's wife. Conclusions: Ribotyping provides strong evidence that the recurrence of Hp infection -which occurs in a small percentage of DU patients after apparently successfuleradicatlon treatment- usually represents regrowth of a temporarily suppressed Hp strain, although a late reinfection with a new strain is also possible.
to detect the organism and to assess the degree of the related inflammatory changes. Objectives: To determine the degree of agreement among 4 gastrointestinal pathologists in the semi-quantitative evaluation ofH. pylori infection and gastritis. Methods: Three slides from pre-determined areas of the stomach of 99 patients with and without H. pylori infection were stained with the Genta stain, coded and examined independently by four pathologists. For each specimen, a visual analog scale graded from 0 (absenVnormal) to 5 (maximal intensity) was used to score: 1) H. pylori; 2) neutrophils; and 3) atrophy. Data were analyzed using kappa statistics. Results: The best interobserver agreement (K = - 0.90) was present for the presence or absence ofH. pylori for all 3 biopsy sites. Agreement on the presence or absence of nentrophils was also excellent (K = 0.8) in antral biopsies and good (K = 0.67) in corpus biopsies. The agreement on semiquantitative scoring was markedly less. When the severity of the infection was evaluated by grouping the six categories into four (none, mild, moderate, and severe) results were improved but still not excellent. The poorest agreement was for atrophy (presence, absence, categories, or group categories): for this parameter K never exceeded 0.2. Conclusions: This group of pathologists had a high level of concordance (99%) on the diagnosis ofH. pylori infection in any particular patient and a very high index in the assessment of the intensity of infection. The agreement was less in the evaluation of active inflammation. When the evaluation concerned a looselydefmed feature such as atrophy, there was essentially no agreement. This study suggests the need for: 1) further assessmentsofpathologists' ability to provide reproducible diagnoses, and 2) better criteria for the diagnosis of "soft" histopathologic features (such as atrophy).
• H. PY1_ORIDECREASES EXPRESSION OF SOMATOSTATIN mRNA IN THE GASTRIC CORPUS AND ANTRUM OF NON-ULCER PATIENTS. Gibbons AH 1, Legon S2, Calam J~. Depts of Gastroenterology ~and Metabolic Medicine 2, Hammersmith Hospital, London, England. Introduction: It is proposed that H. pylori (Hp) causes duodenal ulcers (DU) by increasing gastric acid secretion. Results suggest that reflexes which normally inhibit acid secretion are defective because Hp gastritis decreases mucosal expression of somatostatin. We have reported that eradication of Hp from DU patients increases the expression of somatostatin mRNA inthe gastric antrum, but that sornatostatin mRNA in the corpus does not change. However a group inThe Netherlands have found less somatostatin peptide in the gastric corpus of non-ulcer patients infected with Hp, This might be due to a difference between expression of mRNA and peptide, or a difference between DU and non-ulcer patients. Therefore we compared the expression of somatostatin mRNA in the gastric corpus of non-ulcer patients with and without Hp infection. Methods: Biopsies were taken from the gastric corpus and antrum of 9 HP+ and 8 HP- dyspeptic patients for total RNA extraction and Northern blotting. A 32p labelled eDNA probe for somatostatin was used to detect the mRNA, the signals being quantified by phosphor imaging. GAPDH mRNA levels were measured to correct for differences in loading and transfer of RNA. Results: The expression of somatostatin mRNA was significantly decreased in the gastric corpus o f Hp+ patients (P < 0.003). Median corpus somatostatin mRNA was 0:08 (0.02 - 0.45) in Hp+ patients compared with 0.29 (0.17 - 0.48) in Hp- patients. The expression of somatostatin mRNA was also significantly decreased in the gastric antrum of Hp+ patients (P < 0.0009). Median antral somatostatin mRNA was 0.10 (0.04 - 0.4) in Hp+ patients compared with 0.39 (0.27 - 1.04) in Hp- patients. Somatostatin mRNA was significantly more abundant in the antrum than in the corpus of uninfected patients (P < 0.03) Conclusions: Expression of somatostatin mRNA is decreased in the gastric corpus of non-ulcer patients with Hp infection. This is consistent with the finding of decreased somatostatin peptide in the gastric corpus of these patients. We speculate that Hp affects corpus s0matostatin in non-ulcer patients but not DU patients because corpus gastritis tends to be marked in the former but minimal in the latter. Gastritis and decreased expression of somatostatin are present in the antrum of both groups. These results support the idea that in Hp infection it is the mucosal inflammation that affects expression of somatostatin.
•
THE EFFECT OF GASTRIN RELEASING PEPTIDE.(GRP) INFUSIONS ON THE mRNAS ENCODING GASTRIN AND SOMATOSTATIN IN PATIENTS WITH AND WITHOUT H. PYLORI INFECTION. Gibbons AH I, Legon S=, Calam Jl. Depts of Gastroenterology ~& Metabolic Medicine 2. Hammersmith Hospital; London, UK. Introduction: It has been proposed that H: pylori (Hp) causes peptic ulcers by increasing acid secretion. Hp-associated hypersecretion is most marked during infusion of GRP. To explore the underlying defect we compared the effect of GRP infusions on gastric expression of the mRNAs encoding gastrin and somatostatin between individuals with and without Hp infection. Methods: Dyspeptic non-ulcer patients, 9 Hp+ and 8Hp-, received a 3 hour intravenous infusion of GRP (14-27), 200 pmol/kg/h or vehicle alone on separate occasions. At the end of each infusion endoscopy was performed and biopsies taken from the gastric corpus and antrum for RNA extraction. Somatostatin and gastrin mRNA levels were determined on blots of total RNA using ~P-labelled eDNA probes for human somatostatin and gastrin and the signals quantified using phosphor imaging. GAPDH mRNA levels were measured to correct for RNA loading and transfer variations. Plasma gastrin was measured by radioimmunoassay. Results: Infusion of GRP produced a significant rise in antral gastrin mRNA in the Hp+ patients, but a significant fall in the Hp- group. Plasma gastrin rose in the Hp~- group but not appreciably in the Hp- patients. GRP stimulated a significant rise in antral somatostatin mRNA in the Hp+ group, but not in the Hp- group. Corpus somatostatin mRNA showed a similar trend but the rise in the infected group was not statistically significant. Hp+ HpPlasma gastrin: 295 (200-638)* 140 (123-157) Antrum: gastrin mRNA 127 (86-190)*" 81 (44-145)* Antrum: somatostatin mRNA 140 (85-190)* 93 (66-156) Corpus: somatostatin mRNA 167 (37-270) 66 (35-103) Leve/s post-GRP infusion are expressed as a percentage of values found after centre~ infusion (median and range); mRNA values were determined as peptide mRNA/GAPDH mRNA; * = P < 0.05 Conclusions: Gastrin-releasingpeptide (GRP) leads to a paradoxical inhibition of gastrin mRNA expression in Hp- individuals. The mechanism responsible is unknown but is altered in Hp+ people who show a significant rise in gastrin mRNA on GRP infusion. The mechanism might involve D-cells which are attenuated in Hp gastritis. Somatostatin mRNA only rose significantly in the antrum of Hp+ patients, This supports the idea that GRP stimulates antral D-cells by releasing gastrin,