C. Bilardi

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 δ 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.

A 10-day levofloxacin-based therapy in patients with resistant Helicobacter pylori infection: A controlled trial

BACKGROUND & AIMS Antibiotic resistance is a major issue in anti- Helicobacter pylori treatment. This study was aimed at assessing the efficacy of 2 therapies in patients with resistant H pylori infection. METHODS Patients who had failed 1 or more eradication regimens underwent upper gastrointestinal endoscopy and 2 antral and 2 corpus biopsy specimens were taken for histology and culture. Metronidazole, clarithromycin, and amoxicillin resistance were determined by E-test. Patients were randomly assigned to 2 therapies: 1 group received pantoprazole 40 mg, amoxicillin 1 g, levofloxacin 250 mg, all twice daily for 10 days, and the other group was treated with omeprazole 20 mg twice daily for the first week and omeprazole 20 mg twice daily, tetracycline 250 mg 4 times daily, metronidazole 500 mg twice daily, and bismuth subcitrate 240 mg twice daily for the second week. Therapeutic success was evaluated by 13C urea breath test after 4 weeks of treatment. RESULTS We enrolled 44 patients in the levofloxacin-based regimen and 46 patients in the quadruple therapy. The former was successful in 31 of 44 (70%; 95% confidence interval: 53-87) and the latter in 17 of 46 (37%; 95% confidence interval: 23-47) patients, using intention-to-treat (ITT) analysis (P < .001). The rates of H pylori resistance to metronidazole, clarithromycin, and amoxicillin were 46%, 12%, and 0%, respectively. Resistance to both metronidazole and clarithromycin was found in 10% of cases. CONCLUSIONS Triple therapy containing levofloxacin was better than quadruple therapy. The 70% success rate observed indicates that 10 days of pantoprazole, amoxicillin, and levofloxacin should be considered in patients who had failed 1 or more eradication regimens.

An evaluation of the antireflux properties of sodium alginate by means of combined multichannel intraluminal impedance and pH-metry

Background : Alginate‐based preparations act as mechanical antireflux barrier, which can reduce both acid and non‐acid reflux events and limit the proximal migration of oesophageal refluxate.

Eradication of Helicobacter pylori may reduce disease severity in rheumatoid arthritis.

Background : A triggering infectious agent has long been postulated in rheumatoid arthritis. Data on the possible role of Helicobacter pylori infection are lacking.

Helicobacter pylori infection is not involved in the pathogenesis of either erosive or non‐erosive gastro‐oesophageal reflux disease

Background : The majority of reflux patients have non‐erosive reflux disease.

Comparison of the main oesophageal pathophysiological characteristics between short- and long-segment Barrett's oesophagus.

To assess the oesophageal manometric characteristics and 24‐h pH profiles of patients with both short‐segment and long‐segment Barretts oesophagus and compare them with those of patients with reflux oesophagitis and controls.

Stool antigen assay (HpSA) is less reliable than urea breath test for post-treatment diagnosis of Helicobacter pylori infection

Background : The diagnostic yield of the stool antigen test (HpSA) in evaluating the results of Helicobacter pylori eradication therapy is controversial, but many studies have used only the 13C‐urea breath test (13C‐UBT) as a gold standard which has greatly reduced their relevance.

A study of 4-and 7-day triple therapy with rabeprazole, high-dose levofloxacin and tinidazole rescue treatment for Helicobacter pylori eradication

Background  Helicobacter pylori treatment failure is becoming an emergent problem in clinical practice. Shorter treatment duration should improve compliance to therapy and keep an acceptable H. pylori eradication rate.

Impact of Long-Term Ranitidine and Pantoprazole on Accuracy of [13C]Urea Breath Test

No previous study has analyzed the impact of long-term antisecretory drugs on the precision of [13C]urea breath test (UBT). We assessed the rate of UBT conversion from positive to negative results during 60-day therapy with standard doses of ranitidine and pantoprazole. For this purpose, we recruited 60 dyspeptic patients with H. pylori infection ascertained on the basis of the concomitant results of CLO-test, histology, and UBT. Our patients were randomly assigned to receive ranitidine 300 mg at night or pantoprazole 40 mg in the morning for 60 days. UBT was performed at baseline and on days 14, 30, and 60, while patients were still taking antisecretory drugs. Patients with false-negative UBT on day 60 repeated the test every 3 days until conversion. After overnight fasting, duplicate breath test samples were taken from each patient before and 30 min after ingestion of 75 mg [13C]urea dissolved in 150 ml of 0.033 mol/liter citric acid. Four patients dropped out of the study. Both drugs induced similar false-negative UBTs on day 14 of dosing (P = 0.5). Afterwards, the three false-negative UBTs in the ranitidine group again became positive during therapy and particularly on day 30 of dosing. Of the four false-negative UBTs in the pantoprazole group at day 60, one became positive after 3 and three after 9 days of therapy cessation. Our findings show that the long-term use of ranitidine and pantoprazole at standard doses has different effects on the results of UBT. In the pantoprazole group patients again became positive within 3–9 days after stopping 60-day therapy, whereas in the ranitidine group patients reverted to positive on day 30 of dosing while they were still on treatment and this was likely due to development of tolerance. Therefore, patients taking pantoprazole need at least a 10-day withdrawal before UBT testing, while those taking ranitidine for at least 30 days can undergo UBT without the necessity of a wash-out period.

Comparable Helicobacter pylori eradication rates obtained with 4- and 7-day rabeprazole-based triple therapy: a preliminary study

BACKGROUND Rabeprazole is a new proton pump inhibitor, which has been reported to induce a faster acid suppression than other drugs of the same category. This might be useful to reduce the duration of anti-Helicobacter therapies. AIMS The aim of this study was to assess whether there is the possibility of shortening a rabeprazole-based triple therapy from 7 to 4 days without compromising its efficacy in the eradication of Helicobacter pylori infection. PATIENTS A total of 128 consecutive dyspeptic patients with H. pylori infection were recruited for this controlled, randomized, open and parallel-group trial comparing the efficacy of two durations of the same rabeprazole-based triple therapy. METHODS All patients were subdivided to receive a combination of rabeprazole 20 mg twice daily, clarithromycin 250 mg twice daily and metronidazole 500 mg twice daily (RCM) for 4 days (n = 63) and for 7 days (n = 65). At baseline, they underwent breath 13C-urea test and endoscopy with biopsies for rapid urease testing and histology to confirm infection with H. pylori. Eradication was determined by a negative 13C-urea breath test within 28-32 days after the end of therapy. RESULTS Overall eradication rates were similar for patients treated with the 4- and the 7-day periods (intention-to-treat and per-protocol analyses showed a success rate of 81% versus 78% and 88% versus 85%, respectively; P = NS). Tolerance was similar in both groups. Most adverse events were mild to moderate, and only two patients were withdrawn because of them. CONCLUSIONS The eradication rate of the 4-day regimen was equivalent to that of the same 7-day regimen based on rabeprazole plus clarithromycin and metronidazole. Therefore, the 4-day regimen of RCM seems to give us the possibility of adopting a shorter-than-usual duration of therapy against H. pylori.