Enzo Ierardi

High eradication rates of Helicobacter pylori with a new sequential treatment

Background : Eradication rates of Helicobacter pylori with standard triple therapy are disappointing, and studies from several countries confirm this poor performance.

Systematic review: endoscopic dilatation in Crohn’s disease

Background  Endoscopic dilatation for Crohn’s disease has been evaluated only in some small and heterogeneous studies.

Clarithromycin-Resistant Genotypes and Eradication of Helicobacter pylori

Context Point mutations in the peptidyltransferase region of the 23S ribosomal RNA gene may be responsible for Helicobacter pylori clarithromycin resistance. Contribution This study related mutations to eradication rates in 156 adults treated with clarithromycin regimens for H. pylori infection. Eradication was successful in 14 of 15 patients with either A2142G or A2142C point mutations but in only 11 of 23 patients with the A2143G point mutation. Cautions This was a post hoc subgroup study of selected participants in a multicenter randomized trial. Implications The A2143G point mutation may be associated with a low eradication rate of H. pylori infection. The Editors Helicobacter pylori infection plays a major role in peptic ulcer disease, low-grade mucosa-associated lymphoid tissue lymphoma, and gastric cancer (1), and its eradication dramatically affects the natural history of both peptic ulcer and gastric lymphoma (2). European and U.S. guidelines advised the use of triple therapies (proton-pump inhibitor, clarithromycin plus amoxicillin, or metronidazole) for 7 to 14 days to cure this infection (3, 4). However, H. pylori resistance against clarithromycin is increasing worldwide, reducing the success rate of standard triple therapies to mean values as low as 18% to 44% (5-7). Novel culture-free polymerase chain reaction (PCR)based assays have allowed the detection of the genetic mutations that are involved in the mechanisms of clarithromycin resistance (8, 9). In detail, A2143G and A2142G transitions are the most prevalent point mutations in Europe and the United States (10, 11), while the A2144G mutation is more frequent in Asia (12, 13). Although such genetic mutations have been associated with different degrees of bacterial resistance in vitro, data are still conflicting (7, 14). Moreover, no study has assessed the role of these different mutations on H. pylori treatment outcome. In a recent multicenter study, a novel sequential regimen, consisting of a simple dual therapy given for the first 5 days followed by a triple therapy for the remaining 5 days, achieved a very high cure rate as compared with standard triple therapy (92% vs. 74%) (15). Whether such a high cure rate may depend on increased efficacy of the sequential regimen against the clarithromycin-resistant strains is unknown. We wanted to evaluate the role of different point mutations in the success of eradication therapy and to compare the efficacy of standard triple therapy and the sequential regimen for these mutations. Methods Study Design To assess the role of primary clarithromycin resistance in therapeutic outcome, we designed a post hoc subgroup analysis of a previous study involving 8 Italian centers (15). In detail, we selected patients from those who were previously enrolled by our 2 centers to participate in a multicenter study between January and December 2001 (Figure). Demographic and clinical characteristics of patients enrolled in our substudy were similar to those of patients enrolled in the original multicenter study. Briefly, in the original study, Zullo and colleagues (15) allocated patients who were never treated for H. pylori infection, according to a computer-generated randomization list drawn in each center, to receive standard 7-day treatment (20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin twice daily) or 10-day sequential therapy (20 mg of rabeprazole plus 1 g of amoxicillin twice daily for the first 5 days followed by 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of tinidazole twice daily for the remaining 5 days). To assess H. pylori status, the investigators performed upper endoscopy with several gastric biopsies for histology (Giemsa staining), a rapid urease test, and a standard 13C-urea breath test at entry and at 4 to 6 weeks after therapy. Investigators considered infections to be eradicated when all 3 test results were negative and considered treatment to have failed when at least 1 test result was positive. The local ethics committee approved the protocol, and all participants gave written informed consent. Figure. Flow chart showing data of patients recruited in this substudy from the previous multicenter study. For our current study, we selected 75 of 192 patients who were treated with standard triple therapy and 81 of 185 patients who were treated with the sequential regimen in the 2 participating centers. We recruited patients consecutively from the randomization lists of the previous study, independent of the eradication status. The final study sample included 58 of 140 patients whose infections were eradicated and 17 of 52 patients whose infections were not eradicated after standard triple therapy and 76 of 177 patients whose infections were eradicated and 5 of 8 whose infections were not eradicated after the sequential regimen. Clarithromycin Resistance Assessment We assessed the 3 point mutations (A2142C, A2142G, and A2143G) of clarithromycin resistance by using a validated real-time PCR, as reported elsewhere (16). Briefly, we extracted the DNA by using NucleoSpin Tissue (Macherey-Nagel GmbH & Co., Dren, Germany), according to the manufacturers instructions, applied on paraffin-embedded sections. We applied the same procedure to homogeneous bacterial cultures of H. pylori (positive and negative controls), for which clarithromycin resistance had been previously assessed with Etest (AB BIODISK, Solna, Sweden). We estimated final DNA concentrations by ultraviolet absorbance at 260 nm. Preparation of the Probes and Primers We designed TaqMan minor groove binder (MGB) probes and primers to hybridize with wild-type and mutant DNA by using the Primer Express program and Custom TaqMan SNP Genotyping Assay service (Applied Biosystems, Foster City, California) that synthesized the primers and probes for each mutation. Genotyping Assay The assay reagents for the genotyping single nucleotide mutation from the Assays-by-Design service (Applied Biosystems) consisted of a 40X mix of unlabeled PCR primers and TaqMan MGB probes (FAM and VIC fluorochrome dyelabeled). These assays were designed for the genotyping of specific mutations. Each assay enables scoring of both genotypes in a single well. Since a recent study showed that the conjugation of MGB to oligonucleotides stabilizes nucleic acid duplexes, causing a dramatic increase in oligonucleotide melting temperature (17, 18), we used an attachment of the MGB, which enables the use of shorter fluorogenic probes, thus resulting in improved mismatch discrimination. Our probes were distinguished by being labeled with different fluorescent reporter dyes (FAM dye and VIC dye). A substantial increase in FAM or VIC dye fluorescence indicated homozygosity for the FAM- or VIC-specific allele, while an increase in both signals indicated heterozygosity (19). Real-Time PCR Assay and Allelic Discrimination We performed the real-time PCR procedure according to the method of Wada and colleagues (20). We enclosed positive and negative controls in each assay. We analyzed fluorescence of hybridized probes by multicomponent graphics, where we examined dye-labeled (FAM and VIC), background, and passive control (ROX fluorochrome dye-labeled) fluorescence and expressed them as normalized reporter signal (Rn). We clustered all samples by using the maximum likelihood algorithm based on the ratio of normalized reporter dye signal. The result of the analysis yields 3 major clusters corresponding to the 3 genotypic constituents: wild-type homozygous, mutated-type homozygous, and heterozygous. Characterization of Positive and Negative Controls by Amplification and Sequencing of the Hp23S Fragment We obtained the Hp23S fragment by PCR amplification of H. pylori extracted DNA from homogeneous bacterial cultures (strains with and without clarithromycin resistance, previously assessed by Etest) by using primer Hp23-F (5-CCACAGCGAT GTG GTCTCAG-3) and Hp23-R (5-CTCCATAAGAGCCAAAGCCC-3) according to conventional PCR assay (21). Before sequencing, we purified the PCR products by using the Wizard PCR preps (Promega, Madison, Wisconsin). We performed the sequencing reaction with the same primers for PCR, as described by Sanger and colleagues (22), by using the Dye Terminator 3.1 Ready Reaction Kit (Applied Biosystems) as indicated by the manufacturer. We performed sequencing on the 2 strands of each PCR product with the automated ABI Prism 377 DNA Sequencer (Applied Biosystems) and aligned the resulting nucleotide sequence by using the Sequence Navigator software package (Applied Biosystems). Statistical Analysis We determined sample size before the start of the study on the basis of the available data in the literature. In detail, an eradication rate ranging from 18% to 44% was reported after standard triple therapy in patients with primary clarithromycin-resistant strains (5-7), whereas the sequential regimen eradicated the infection in 79% of such patients (15). Assuming a high eradication rate for the triple therapy (45%) and a relatively poor success rate for the sequential regimen (70%) in patients with primary clarithromycin-resistant strains, we calculated that at least 68 patients per group were needed to detect a statistically significant difference with 0.8 power and an level of 0.05 (2-sided). After the study was completed, we realized that our sample size estimate provided the necessary number of clarithromycin-resistant patients and should have been inflated, on the basis of a presumed overall rate of clarithromycin resistance, to provide an estimate of total sample size. We compared eradication rates by H. pylori clarithromycin-resistant strain mutation (A2142C, A2142G, and A2143G) by using the Fisher exact test or chi-square test, as appropriate. We determined point mutation groupings after reviewing eradication rates by individual mutation. We compared clinical characteristics among the different groups by using the Student t-test for unpaired da

Effects of Helicobacter pylori eradication on early stage gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND & AIMS Different remission rates of gastric low-grade, B-cell, mucosa-associated lymphoid tissue (MALT) lymphoma have been reported after Helicobacter pylori eradication. We assessed the long-term remission and relapse rates of early stage MALT lymphoma in patients treated only by H pylori eradication and identified factors that might predict outcome. METHODS This systematic review analyzed data from 32 studies, including 1408 patients. RESULTS The MALT lymphoma remission rate was 77.5% (95% confidence interval, 75.3-79.7), and was significantly higher in patients with stage I than stage II(1) lymphoma (78.4% vs 55.6%; P = .0003) and in Asian than in Western groups (84.1% vs 73.8%; P = .0001). Neoplasia confined to the submucosa regressed more frequently than that with deeper invasion (82.2% vs 54.5%; P = .0001); patients with lymphoma localized to the distal stomach experienced regression more frequently than those with lymphoma of the proximal stomach (91.8% vs 75.7%; P = .0037). The remission rate was higher among patients without the API2-MALT1 translocation than in those with this translocation (78% vs 22.2%; P = .0001). In an analysis of data from 994 patients, 7.2% experienced lymphoma relapse during 3253 patient-years of follow-up evaluation, with a yearly recurrence rate of 2.2%. Infection and lymphoma were cured by additional eradication therapy in all patients with H pylori recurrence (16.7%). Five (0.05%) of the patients initially cured of lymphoma developed high-grade lymphoma within 6 to 25 months of therapy. CONCLUSIONS H pylori eradication is effective in treating approximately 75% of patients with early stage gastric lymphoma. Long-term follow-up evaluation of these patients is needed to detect early lymphoma relapse or progression.

Lactobacillus reuteri therapy to reduce side-effects during anti-Helicobacter pylori treatment in children: a randomized placebo controlled trial.

Helicobacter pylori eradication fails in about 25–30% of children, particularly because of the occurrence of resistance to antibiotics and side‐effects.

A 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses

Background : A standard third‐line treatment is lacking, and European guidelines recommend performing culture in these patients. However, the use of this procedure as ‘routine practice’ is definitively not feasible.

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure.

Background : Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used.

A third-line levofloxacin-based rescue therapy for Helicobacter pylori eradication.

BACKGROUND Helicobacter pylori infection persists in a considerable proportion of patients after both first- and second-line current treatments. A standard therapy for re-treatment in such refractory patients is still lacking. This study aimed to evaluate the efficacy of a levofloxacin-amoxycillin combination in patients who previously failed two or more therapeutic attempts. PATIENTS AND METHODS Consecutive patients with persistent Helicobacter pylori infection were enrolled. Bacterial infection was assessed by rapid urease test and histology on gastric biopsies at endoscopy. Patients were assigned to receive a 10-day triple therapy, comprising rabeprazole 20 mg b.d., levofloxacin 250 mg b.d., and amoxycillin 1 g b.d. Four to 6 weeks after therapy, Helicobacter pylori eradication was assessed by a further endoscopy or 13C urea breath test. RESULTS Overall, 36 patients were enrolled, but two patients were lost to follow-up. Helicobacter pylori was successfully cured in 30 patients, giving an 83.3% (95% CI=71.2-95.5) and 88.2% (95% CI=77.4-99) eradication rate at intention-to-treat and per protocol analysis, respectively. Compliance was good in all but two patients, who discontinued the treatment at 8 and 6 days, respectively, on account of glossitis. No major side-effects were reported, whilst 7 (20.1%) patients complained of mild side-effects. CONCLUSIONS This study demonstrates that a 10-day levofloxacin-amoxycillin triple therapy is a safe and successful third-line therapeutic approach for Helicobacter pylori eradication.

Inhibition of Helicobacter pylori Infection in Humans by Lactobacillus reuteri ATCC 55730 and Effect on Eradication Therapy: A Pilot Study

Background:  Several studies report an inhibitory effect of probiotics on Helicobacter pylori.

High rate of Helicobacter pylori eradication with sequential therapy in elderly patients with peptic ulcer: a prospective controlled study

Background : Helicobacter pylori eradication rates with triple therapies are decreasing, and few data in elderly patients are available. A 10‐day sequential regimen succeeded in curing such H. pylori infection in unselected patients.