Effect of Helicobacter pylori eradication on 24-hour gastric pH and duodenal gastric metaplasia.

Published data on the regression of the extent of duodenal gastric metaplasia (DGM) after the eradication of Helicobacter pylori infection and the normalization of the organism-induced alterations in gastric physiology are scanty and controversial. Therefore, we decided to assess the circadian pattern of gastric acidity and the degree of DGM before and one year after H. pylori eradication in a group of duodenal ulcer patients. Fifteen consecutive H. pylori-positive patients with endoscopically proven duodenal ulcer were recruited for this study. The diagnosis of H. pylori infection was based on CLO-test and histology, and DGM was assessed on four bulb biopsies taken before and one year after H. pylori eradication. At the same time, gastric pH was measured by 24-hr continuous intraluminal recording. H. pylori eradication was ascertained by means of concomitant negative CLO-test and histology performed both four weeks after the end of the eradicating treatment and at the one-year endoscopic control. After successful cure, all patients discontinued any antiulcer medication. The mean 24-hr gastric pH was 1.7 +/- 0.4 before and 1.6 +/- 0.4 after one year of H. pylori eradication (P = 0.75). DGM improved in three cases, worsened in four cases, and was unchanged in eight cases at the one-year control (P = 0.87). No correlation was found between 24-hr gastric pH and DGM (P = NS) both at baseline and one year after eradication. Our results show that neither circadian gastric acidity nor DGM change significantly one year after H. pylori eradication in duodenal ulcer patients. Thus, the disappearance of H. pylori infection does not determine any increase in gastric pH and any reversal of gastric-type epithelium in the duodenum.

The impact of antibiotic resistance on the efficacy of three 7-day regimens against Helicobacter pylori.

BACKGROUND: Antibiotic resistance affects the success of anti-Helicobacter pylori therapies and varies greatly from country to country. AIM: To compare the efficacy of three short-term triple regimens in relation to H. pylori primary resistance in our region. METHODS: We enrolled 210 H. pylori-positive dyspeptic patients for this randomized, open, parallel-group study. Three arms of 70 patients each received the following 1-week regimens: (1) ranitidine bismuth citrate 400 mg b.d. + clarithromycin 250 mg b.d. + metronidazole 500 mg b.d. (RCM); (2) bismuth subcitrate 240 mg b.d. + amoxycillin 1000 mg b.d. + metronidazole 500 mg b.d. (BAM); (3) omeprazole 20 mg o.d. + clarithromycin 250 mg b.d. + metronidazole 500 mg b.d. (OCM). H. pylori was assessed by CLO-test and histology before and 4 weeks after therapy. Antibiotic resistance was assessed by E-test. RESULTS: On intention-to-treat analysis RCM was more effective than OCM (84% vs. 69%; P < 0.03) and BAM (84% vs. 63%; P < 0.004). MIC determination was successful in 117 out of 210 patients (55%); metronidazole resistance was present in 52 out of 117 patients (44%) and clarithromycin resistance was present in 17 out of 117 patients (14%). Excellent cure rates were achieved when strains were sensitive to both antibiotics (100% with RCM and BAM and 90% with OCM), whereas RCM was superior to OCM (P=0.009) and BAM (P=0.001) with respect to overall resistant strains (94% vs. 57% and 38%, respectively). CONCLUSIONS: One-week RCM is the best regimen to eradicate H. pylori in our geographical area. This seems to be linked to the better ability of RCM compared to OCM and BAM in overcoming the high prevalence of H. pylori resistance to both metronidazole and clarithromycin in our region.

Effect of gastric acid suppression on 13C-urea breath test: comparison of ranitidine with omeprazole.

BACKGROUND: The assessment of the effect of H2 antagonists on the results of the urea breath test has produced controversial results. AIM: To assess whether standard doses of both omeprazole and H2 blockers can adversely influence the accuracy of the urea breath test. METHODS: Sixty dyspeptic patients with ascertained Helicobacter pylori infection were recruited for this prospective, open study. They were randomized to receive either omeprazole 20 mg at 08:00 hours (n = 30) or ranitidine 300 mg at 22:00 hours (n = 30) for 14 days. The urea breath test was performed at baseline, on day 14, while patients were still taking the antisecretory drugs, and on day 21, 1 week after their cessation. Duplicate breath samples were collected after ingestion of 75 mg 13C-urea + citric acid. A delta value > 5 per thousand was considered positive. RESULTS: On day 14 the median delta values had declined, but not significantly (P = 0. 07) compared to baseline (13.79 vs. 22.39) with omeprazole, while they had increased (P = 0.27) with ranitidine (27.21 vs. 19.46). On the same day there were five out of 30 (17%) and five out of 28 (18%) false-negative results in the omeprazole and ranitidine groups, respectively. All these cases became positive again on day 21. However, in eight cases treated with omeprazole and 13 treated with ranitidine, there was an increase of 14-day delta values compared to baseline. CONCLUSIONS: Our study shows that both omeprazole and ranitidine at standard doses are able to negatively affect the results of the urea breath test. Their adverse effect resolves within 7 days of drug cessation and therefore the withdrawal of these drugs 7 days before testing seems to be sufficient to avoid false-negative results. The surprising finding that both antisecretory drugs reduce delta values in one group and increase them in another group of patients deserves further study.

Comparison of isotope ratio mass spectrometry and nondispersive isotope-selective infrared spectroscopy for 13C-urea breath test.

OBJECTIVES: The 13C-urea breath test (UBT) is a sensitive and noninvasive method to diagnose Helicobacter pylori infection, but mass spectrometry (IRMS) is very expensive. The aims of this study were to compare the new low-priced infrared spectroscopy with IRMS in detecting the infection and to assess the influence of feeding on test accuracy. METHODS: One hundred thirty-four patients with dyspeptic symptoms were recruited. Of these, 74 were infected and 60 uninfected on the basis of both CLO-test and histology. A subgroup of 37 patients (22 H. pylori-positive and 15 H. pylori-negative) was studied under fasting and nonfasting conditions on two different days. Duplicate breath samples were analyzed with two IRMS systems (Breath Mat and ABCA) and an infrared spectrometer (IRIS) before, 15 min, and 30 min after ingestion of 75 mg 13C-urea with citric acid. In 37 patients the test was repeated the day after the fasted one and was performed 60 min after a meal of 800 Kcal. RESULTS: There was a close correlation between IRIS and Breath Mat (r = 0.969 at 15 min and r = 0.977 at 30 min; p < 0.0001), IRIS and ABCA (r = 0.963 at 15 min and r = 0.985 at 30 min; p < 0.0001), and Breath Mat and ABCA (r = 0.987 at 15 min and r = 0.981 at 30 min; p = 0.0001). The sensitivity ranged from 97-100% at both times with all devices, although the specificity was slightly inferior with the infrared system than with the two IRMS machines (95% vs 98-100% at 30 min), but the difference was not significant (p = NS). Food intake produced three false negative results in all three machines and a systematic shift to lower 6 values in infected patients. CONCLUSIONS: Infrared spectroscopy can be considered a valid alternative to mass spectroscopy for the diagnosis of H. pylori infection. Fasting is required to guarantee an accurate test.

Head-to-head comparison of 1-week triple regimens combining ranitidine or omeprazole with two antibiotics to eradicate Helicobacter pylori.

BACKGROUND: Triple therapies containing omeprazole and ranitidine have been shown to be equivalent in eradicating H. pylori infection, but have been assessed either separately or head-to-head, only in small trials. AIM: To carry out a large randomized controlled study comparing omeprazole and ranitidine combined with two antibiotic combinations for 1 week. METHODS: Three hundred and twenty H. pylori-positive patients were randomly subdivided into four equal-sized groups and received one of the following treatments: OAM = omeprazole 20 mg b.d. + amoxycillin 1 g b.d. + metronidazole 500 mg b.d.; RAM = ranitidine 300 mg b.d. + amoxycillin 1 g b.d. + metronidazole 500 mg b.d.; OAC = omeprazole 20 mg b.d. + amoxycillin 1 g b.d. + clarithromycin 250 mg t.d.s.; RAC = ranitidine 300 mg b.d. + amoxycillin 1 g b.d. + clarithromycin 250 mg t.d.s. The assessment of H. pylori status was performed before and 4 weeks after the end of therapy by means of CLO-test and histology. H. pylori infection was considered to be eradicated when both tests were negative. RESULTS: OAM and RAM eradicated H. pylori in 89% and 85% of cases on per protocol (P = 0.48) and in 77% and 75% of cases on intention-to-treat analyses (P = 0.71). OAC and RAC eradicated H. pylori in 67% and 70% of cases on per protocol (P = 0.68) and in 57% and 64% of cases on intention-to-treat analyses (P = 0.41). In contrast, there was significant difference between OAM and OAC (P<0.01) and between RAM and RAC (P<0.05). Side-effects occurred in 15%, 10%, 17% and 16% of patients with respect to the above four subgroups. CONCLUSIONS: Omeprazole and ranitidine combined with two antibiotics for 1 week are equally effective in the eradication of H. pylori infection, and these results question the role of profound acid suppression in the eradication of the bacterium.

Histological and functional recovery in patients with multifocal atrophic gastritis after eradication of Helicobacter pylori infection.

BACKGROUND/AIMS: To assess the effect of Helicobacter pylori eradication on gastric histology and physiology in patients with multifocal atrophic gastritis over 1-year period. PATIENTS: Fourteen consecutive patients with histological evidence of chronic gastritis and Helicobacter pylori infection diagnosed by histology and serology entered this study. Patients with pernicious anaemia, gastric ulcer or carcinoma, duodenal ulcer, reflux oesophagitis and regular intake of nonsteroidal anti-inflammatory drugs were excluded. METHODS: Patients underwent triple anti-Helicobacter treatment for one week, which resulted successful in all subjects on the basis of negative CLO test and histology as well as 50% decrease in IgG antibodies after 4 weeks and 6 months of treatment, respectively. Histological and functional investigations were performed at baseline, 6 and 12 months after Helicobacter pylori eradication. Histological assessment of inflammatory cell infiltrates was performed on multiple biopsy specimens of the corpus and fundus. Functional tests were 24-hour continuous gastric pH-metry, fasting serum gastrin assay and pepsinogen I levels. RESULTS: There was a progressive significant improvement (p < 0.01-0.001) in acute and chronic inflammatory cell infiltrates in the gastric mucosa throughout the 12-month period. Functional recovery with increase in gastric acidity (p < 0.01) and decrease in gastrin and pepsinogen I levels (p < 0.001) was more evident at the 6-month than at the 12-month checkpoint after Helicobacter pylori eradication (p = NS for gastric pH and p < 0.02 for the other two variables) between 6 and 12 months. CONCLUSIONS: Eradication of Helicobacter pylori infection significantly improves the inflammatory status of oxyntic mucosa and this promotes an almost complete functional recovery. However, the non-parallel behaviour of gastric acidity, which was maximal at 6-month checkpoint, and histological parameters which continued to improve throughout the entire 12-month observation period, seems to indicate that removal of acid-inhibitory substances induced by Helicobacter pylori infection was also responsible for the more rapid recovery of gastric secretory function.

Optimal duration of therapy combining ranitidine bismuth citrate with clarithromycin and metronidazole in the eradication of Helicobacter pylori infection.

BACKGROUND: Ranitidine bismuth citrate (RBC) co-prescribed with clarithromycin and metronidazole for 1 week has been shown to be an effective eradicating regimen for Helicobacter pylori. AIM: To determine the optimal duration of this regimen. METHODS: A series of 165 dyspeptic patients were recruited for this randomized, open, parallel-group study. They were subdivided into three groups receiving RBC 400 mg b.d. plus clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. for three different periods (4, 7 and 10 days). H. pylori infection was assessed by the concomitant positivity of CLO-test and histology performed at the pre-entry endoscopy. The bacterium was considered eradicated on the basis of a negative 13C-urea breath test performed at least 28 days after the completion of treatment. RESULTS: The three subgroups were well matched and 16 patients dropped out of the study for many reasons (six in the 4-day, five in the 7-day and five in the 10-day treatment regimens). Intention-to-treat cure rates were 60%, 84% and 85%, and the per-protocol rates 67%, 92% and 94% in the 4-day, 7-day and 10-day treatment regimens, respectively. There was a significant difference, P = 0.003-0.006 on intention-to-treat and P = 0.001-0. 002 on per protocol analysis between the 4-day and the 7-day and the 4-day and the 10-day periods, respectively. The 7-day and 10-day periods did not differ from each other. Side-effects were reported in 9%, 14% and 20% of the 4-, 7- and 10-day regimens. They led to stopping treatment in four cases (one in the 7-day and three in the 10-day period). There was no statistical difference among them. CONCLUSIONS: Reducing the duration of RBC-based triple therapy to 4 days provides a low and unacceptable rate of H. pylori eradication. As there is no difference between 7 and 10 days of treatment, 1 week represents the optimal time period for this kind of treatment, based on RBC plus two antibiotics.

Effect of one-month treatment with nonsteroidal antiinflammatory drugs (NSAIDs) on gastric pH of rheumatoid arthritis patients.

The use of NSAIDs is strongly associated with peptic ulceration. The inhibition of prostaglandin synthesis with the consequent increase of gastric acidity is considered a possible mechanism. Therefore we decided to assess the effect of one-month treatment with NSAIDs on the circadian gastric pH of rheumatoid arthritis (RA) patients. We studied 11 consecutive patients (one man and 10 women, median age 55, range 26-72 years) with confirmed RA. None was H. pylori positive. A 24-hr gastric pH recording was performed both in basal conditions and after one-month treatment with either indomethacin 150 mg/day (eight cases) or ketoprofen 300 mg/day (three cases). Only the 10 female patients were eligible for final analysis, and six matched healthy subjects not taking NSAIDs were used as control group. The number of 24-hr pH readings for various pH thresholds was calculated for both populations. The highest acid levels (pH < 3.0) did not differ between the two pH profiles of the control group (7440 vs 7391, P = NS), while they predominated after the one-month NSAID treatment (10,339 vs 11,440, P < 0.001) in RA patients. These findings show that there is an increased gastric acidity after one-month of treatment with NSAIDs in female patients with RA of recent onset. This may sustain the rationale of using antisecretory agents to prevent gastroduodenal ulcerations in these patients.

Comparison of 24-h control of gastric acidity by three different dosages of pantoprazole in patients with duodenal ulcer.

BACKGROUND: It is now clear that the extent to which gastric acid secretion must be suppressed varies with the clinical condition being treated. AIM: To assess the 24-h control of gastric acidity and the individual response variability of three different doses of pantoprazole. METHODS: Sixty-four duodenal ulcer patients were recruited for this prospective, randomized, multicentre, double-blind, parallel-group study. They were subdivided into three well-matched groups treated with 20 mg o.m., 40 mg o.m. and 40 mg b.d. of pantoprazole, respectively. Endoscopy and intragastric pH monitoring were performed in each patient before and after 14 days of treatment. RESULTS: Fifty-five patients were eligible for final analysis (17 treated with 20 mg o.m., 18 with 40 mg o.m. and 20 with 40 mg b.d. pantoprazole). The ulcer crater healed in 94, 88 and 95% of cases, respectively. The three dosages of pantoprazole produced significant increases in gastric pH compared to basal levels (P < 0.0001). There was also a clear dose-dependent pharmacodynamic effect, which augmented on moving from the lowest dosage of 20 mg o.m. pantoprazole to the highest dosage of 40 mg b.d. (P < 0.01-0.001). The inter-individual response variability within the three treatment groups was more marked with the dose of 20 mg than with the two higher doses of pantoprazole. CONCLUSIONS: All three doses of pantoprazole we tested are highly effective in decreasing gastric acidity and there is a clear dose-dependent pharmacodynamic effect on moving from the lowest to the highest dosage. The greatest inter individual variation in the degree of acid inhibition was seen with pantoprazole 20 mg o.m., while the majority of patients responded adequately to the two higher doses of the drug.