Gerardo Nardone

Methodology and indications of H2-breath testing in gastrointestinal diseases: the Rome Consensus Conference

BACKGROUND Breath tests represent a valid and non-invasive diagnostic tool in many gastroenterological conditions. The rationale of hydrogen-breath tests is based on the concept that part of the gas produced by colonic bacterial fermentation diffuses into the blood and is excreted by breath, where it can be quantified easily. There are many differences in the methodology, and the tests are increasingly popular. AIM The Rome Consensus Conference was convened to offer recommendations for clinical practice about the indications and methods of H2-breath testing in gastrointestinal diseases. METHODS Experts were selected on the basis of a proven knowledge/expertise in H2-breath testing and divided into Working Groups (methodology; sugar malabsorption; small intestine bacterial overgrowth; oro-coecal transit time and other gas-related syndromes). They performed a systematic review of the literature, and then formulated statements on the basis of the scientific evidence, which were debated and voted by a multidisciplinary Jury. Recommendations were then modified on the basis of the decisions of the Jury by the members of the Expert Group. RESULTS AND CONCLUSIONS The final statements, graded according to the level of evidence and strength of recommendation, are presented in this document; they identify the indications for the use of H2-breath testing in the clinical practice and methods to be used for performing the tests.

Empirical levofloxacin-containing versus clarithromycin-containing sequential therapy for Helicobacter pylori eradication: a randomised trial

Background and aims Antimicrobial drug resistance is a major cause of the failure of Helicobacter pylori eradication and is largely responsible for the decline in eradication rate. Quadruple therapy has been suggested as a first-line regimen in areas with clarithromycin resistance rate >15%. This randomised trial aimed at evaluating the efficacy of a levofloxacin-containing sequential regimen in the eradication of H pylori-infected patients in a geographical area with >15% prevalence of clarithromycin resistance versus a clarithromycin-containing sequential therapy. Methods 375 patients who were infected with H pylori and naïve to treatment were randomly assigned to one of the following treatments: (1) 5 days omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by 5 days omeprazole 20 mg twice daily + clarithromycin 500 mg twice daily + tinidazole 500 mg twice daily; or (2) omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by omeprazole 20 mg twice daily + levofloxacin 250 mg twice daily + tinidazole 500 mg twice daily; or (3) omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by omeprazole 20 mg twice daily + levofloxacin 500 mg twice daily + tinidazole 500 mg twice daily. Antimicrobial resistance was assessed by the E-test. Efficacy, adverse events and costs were determined for each group. Results Eradication rates in the intention-to-treat analyses were 80.8% (95% CI, 72.8% to 87.3%) with clarithromycin sequential therapy, 96.0% (95% CI, 90.9% to 98.7%) with levofloxacin-250 sequential therapy, and 96.8% (95% CI, 92.0% to 99.1%) with levofloxacin-500 sequential therapy. No differences in prevalence of antimicrobial resistance or incidence of adverse events were observed between groups. Levofloxacin-250 therapy was cost-saving compared with clarithromycin sequential therapy. Conclusion In an area with >15% prevalence of clarithromycin resistant H pylori strains, a levofloxacin-containing sequential therapy is more effective, equally safe and cost-saving compared to a clarithromycin-containing sequential therapy.

Helicobacter pylori and molecular events in precancerous gastric lesions

Gastric cancer can be divided into intestinal type and diffuse type that differ substantially in epidemiology and pathogenesis. The most important aetiological factor associated both with intestinal and diffuse gastric cancer, is Helicobacter pylori.

Helicobacter pylori and gastric malignancies

Despite decreasing incidence during the last 50 years, gastric cancer still ranks as one of the most frequent cancers. A multifactorial model of human gastric carcinogenesis is currently accepted in which different dietary and nondietary factors, including genetic susceptibility of the host and Helicobacter pylori infection are involved at different stages in the cancer process. On the molecular level, at least two phenotypes, associated with distinct pathways of genome destabilization, have been identified. However, applying new technologies such as cDNA microarrays a new era in the analysis of molecular markers has started. This molecular technology may open the path towards novel treatment modalities, i.e. gene therapy. Epidemiological, biological, and molecular genetic studies have also implicated the role of H. pylori in lymphomagenesis. Knowledge of pathogenesis and therapy is increasing while good epidemiological data are rare. Many studies have demonstrated that MALT-type lymphomas develop along two different pathways: t(11;18)-positive cases, and t(11;18)-negative cases. Meanwhile, a third translocation could be detected, the t(14;18), opening the discussion of a possible third pathway of lymphoma development.Clinical outcomes of Helicobacter pylori infection are diverse and caused by the variability of H. pylori virulence factors, host susceptibility, environmental factors and their interactions. Prospective epidemiological studies have clearly shown the relationship between H. pylori infection and gastric cancer. In addition, studies in animal models such as Mongolian gerbils with or without the addition of low‐dose chemical carcinogens demonstrated that H. pylori infection can develop gastric carcinoma. Experimental studies have shown that virulence factors of H. pylori interact with gastric epithelial cell signaling related to carcinogenesis.

Expression of COX-2, mPGE-synthase1, MDR-1 (P-gp), and Bcl-xL: a molecular pathway of H pylori-related gastric carcinogenesis.

Helicobacter pylori up‐regulates cyclo‐oxygenase‐2 (COX‐2) expression, which in turn is involved in tumourigenesis. Recently, a causal link between COX‐2 and multidrug resistance 1 (MDR‐1) gene expression, implicated in cancer chemoresistance, has been demonstrated. Thus, the expression of COX‐2 and the downstream enzyme involved in PGE2 biosynthesis, microsomal PGE‐synthase1 (mPGES1), was correlated with P‐gp, the product of MDR‐1, and the anti‐apoptotic protein, Bcl‐xL, in gastric biopsies from patients with H pylori infection and in patients with gastric cancer. In a retrospective analysis of endoscopic and pathology files, 40 H pylori‐negative patients (Hp−), 50 H pylori‐positive patients who responded to eradication therapy (Hp+R), 84 H pylori‐positive patients who did not respond to eradication therapy (Hp+NR), and 30 patients with gastric cancer (18 intestinal and 12 diffuse types) were selected. COX‐2, mPGES1, P‐gp, and Bcl‐xL were detected by immunohistochemistry. COX‐2, mPGES1, P‐gp, and Bcl‐xL expression was undetectable in gastric mucosa from Hp− patients. By contrast, COX‐2 and mPGES1 expression was detected in 42% and 44% of Hp+R patients, respectively, and in up to 66% (range 63–66%) of Hp+NR patients (p < 0.05). The expression of COX‐2 and mPGES1 correlated significantly (p < 0.0001) with that of P‐gp and Bcl‐xL. High levels of COX‐2, mPGES1, P‐gp, and Bcl‐xL expression were found in intestinal‐type gastric cancer samples. In conclusion, H pylori‐dependent induction of COX‐2 and mPGES1 is associated with enhanced production of P‐gp and Bcl‐xL that may contribute to gastric tumourigenesis and resistance to therapy. Copyright

Failure of first-line eradication treatment significantly increases prevalence of antimicrobial-resistant Helicobacter pylori clinical isolates

Objectives: Helicobacter pylori infection is a major health problem worldwide, and effective eradication of the infection is mandatory. The efficacy of recommended eradication regimens is approximately 70%. To avoid treatment failure and the consequent development of secondary resistance(s), it is important to choose the most appropriate first-line treatment regimen. This choice should also be made based on the knowledge of the antimicrobial resistance peculiar to a given geographical area. We evaluated the prevalence of antimicrobial-resistant H pylori strains isolated from naive patients and from patients with previous unsuccessful treatments. Methods: This study examined 109 H pylori-infected subjects (Group 1) who had never received an eradication treatment and 104 H pylori-infected subjects (Group 2) who had failed one or more eradication treatments. Resistance to amoxicillin (AMO), tetracycline (TET), clarithromycin (CLA), metronidazole (MET) and levofloxacin (LEV) was determined using the epsilometer test. The significance of differences was evaluated by the χ2 test. Results: The prevalence of antimicrobial resistance was 0% versus 3.1% to AMO, 0% versus 2% to TET, 27% versus 41.3% to MET (p<0.05), 18% versus 45.8% to CLA (p<0.05) and 3% versus 14.6% to LEV (p<0.05) in Group 1 vs Group 2, respectively. In Group 2, there was an increased prevalence of H pylori strains resistant to multiple antimicrobials. Conclusions: This study confirms the high prevalence of H pylori strains resistant to CLA and MET, and indicates that unsuccessful treatments significantly increase resistance. Choosing eradication regimens other than standard triple therapy as a first-line therapy should be advisable in areas with high primary antimicrobial resistance prevalence.

Pretreatment antimicrobial susceptibility testing is cost saving in the eradication of Helicobacter pylori

Abstract Background & Aims: The major obstacle to 100% effective eradication of Helicobacter pylori infection is represented by antimicrobial-resistant H. pylori strains. This randomized study was designed to evaluate whether regimens based on pretreatment susceptibility testing were more effective and cost saving compared with standard nonsusceptibility testing-based therapy in the eradication of H. pylori infection. Methods: We studied 150 consecutive H. pylori -infected dyspeptic subjects. Patients were randomly assigned to omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, and metronidazole 500 mg twice daily for 7 days or to omeprazole 20 mg twice daily and 2 antimicrobials chosen based on susceptibility testing. H. pylori status was reevaluated 12 weeks after the end of treatment by the 13 C-urea breath test. Results: Susceptibility testing-based regimens led to the following results. (1) Eradication rates were 97.3% (95% confidence interval [CI], 91.2%–99.5%) (71 of 73) and 94.6% (95% CI, 87.6%–98.3%) (71 of 75) in the per-protocol and intention-to-treat analysis, respectively. These were significantly higher ( P Conclusions: Pretreatment antimicrobial susceptibility testing is more effective and cost saving and, in health systems that confirm cost advantage, microbial susceptibility testing should be routinely used for eradication of H. pylori infection.

Effects of long‐term PPI treatment on producing bowel symptoms and SIBO

Eur J Clin Invest 2011; 41 (4): 380–386

Efficacy of 5-Day Levofloxacin-Containing Concomitant Therapy in Eradication of Helicobacter pylori Infection

BACKGROUND & AIMS Helicobacter pylori have become resistant to antimicrobial agents, reducing eradication rates. A 10-day sequential regimen that contains levofloxacin was efficient, safe, and cost saving in eradicating H pylori infection in an area with high prevalence of clarithromycin resistance. We performed a noninferiority randomized trial to determine whether a 5-day levofloxacin-containing quadruple concomitant regimen was as safe and effective as the 10-day sequential regimen in eradicating H pylori in previously untreated patients. METHODS We randomly assigned patients with H pylori infection to groups that were given 5 days of concomitant therapy (esomeprazole 40 mg twice daily, amoxicillin 1 g twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily; n = 90) or 10 days of sequential therapy (esomeprazole 40 mg twice daily, amoxicillin 1g twice daily for 5 days followed by esomeprazole 40 mg twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily for 5 more days; n = 90). Antimicrobial resistance was assessed by the E-test. Efficacy, adverse events, and costs were determined. RESULTS Intention-to-treat analysis showed similar eradication rates for concomitant (92.2%; 95% confidence interval [CI], 84.0%-95.8%) and sequential therapies (93.3%; 95% CI, 86.9%-97.3%). Per-protocol eradication results were 96.5% (95% CI, 91%-99%) for concomitant therapy and 95.5% for sequential therapy (95% CI, 89.6%-98.5%). The differences between sequential and concomitant treatments were 1.1% in the intention-to-treat study (95% CI; -7.6% to 9.8%) and -1.0% in the per-protocol analysis (95% CI; -8.0% to 5.9%). The prevalence of antimicrobial resistance and incidence of adverse events were comparable between groups. Concomitant therapy cost

Protective effects of Lactobacillus paracasei F19 in a rat model of oxidative and metabolic hepatic injury

9 less than sequential therapy. CONCLUSIONS Five days of levofloxacin-containing quadruple concomitant therapy is as effective and safe, and less expensive, in eradicating H pylori infection than 10 days of levofloxacin-containing sequential therapy.