Eradication of Helicobacter pylori infection

Eradication of Helicobacter pylori infection has become an important issue recently, because this bacterial species cluster can cause many gastrointestinal diseases. Elevated antibiotic resistance is related to an increasing failure rate of H. pylori eradication. Standard triple therapy is still the first-line therapy; however, according to the Maastricht IV Consensus Report, it should be abandoned in areas of high clarithromycin resistance. Alternative first-line therapies include bismuth-containing quadruple therapy, sequential, concomitant, and hybrid therapies. Quinolone-based triple therapy may be considered as first-line therapy in areas of clarithromycin resistance >15–20% and quinolone resistance <10%. Unique second-line therapy is still unclear, and bismuth-containing quadruple therapy or levofloxacin-based triple therapy can be used as rescue treatment. Third-line therapy should be under culture guidance to select the most effective regimens (such as levofloxacin-based, rifabutin-based, or furazolidone-based therapies). Antibiotics resistance, patient compliance, and CYP 2C19 genotypes could influence the outcome. Clinicians should use antibiotics according to local reports.     

Eradication of Helicobacter pylori infection reverses E-cadherin promoter hypermethylation

BACKGROUND: E-cadherin methylation is important in gastric carcinogenesis. Reversing hypermethylation may halt the carcinogenic process. We have previously reported that Helicobacter pylori infection is associated with E-cadherin methylation in chronic gastritis patients. AIM: To examine if eradication of H pylori could reverse E-cadherin methylation. METHODS: Patients with dyspepsia and positive for H pylori infection, with a mucosal biopsy showing chronic active gastritis, were randomised to receive H pylori eradication therapy (group 1, n = 41) or no treatment (group 2, n = 40), and were followed up prospectively. Gastric mucosae were taken for methylation assay at week 0 (before treatment) and week 6 (after treatment). Archived specimens of intestinal metaplasia with H pylori infection (n = 22) and without (n = 19) were retrieved for methylation analysis. Methylation was assessed using methylation specific polymerase chain reaction and sequencing. RESULTS: Methylation at E-cadherin was detected in 46% (19/41) and 17% (7/41) of patients at weeks 0 and 6, respectively, in group 1 (p = 0.004); 78.9% (15/19) of specimens were unmethylated after eradication of H pylori. Mucosal biopsy showed chronic inactive gastritis in 35 patients, intestinal metaplasia in one, and normal mucosa in five at week 6. Methylation was detected in 47.5% (19/40) and 52.5% (21/40) of patients at weeks 0 and 6, respectively, in group 2 (P = 0.5). Gastric mucosal biopsy showed persistent chronic active gastritis in all cases. Methylation frequency did not differ in H pylori positive or negative intestinal metaplastic specimens (72.7% v 63%; p = 0.5). CONCLUSION: H pylori eradication therapy could reverse methylation in patients with chronic gastritis. This demonstrates an environmental effect on methylation.     

Eradication of Helicobacter pylori infection did not lead to cure of duodenal mucosa-associated lymphoid tissue lymphoma

Duodenal mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, and little is known about its clinical course or association with Helicobacter pylori infection. This report describes the case of a 76-year-old man with a polypoid mass in the duodenal bulb, diagnosed as low-grade MALT lymphoma. H. pylori infection in the duodenal mucosa was confirmed by histology with silver stain. Endoscopic examination showed that the gross lesion regressed after the eradication of H. pylori despite its histopathologic persistence. Ten months later, however, cervical and intraperitoneal lymphadenopathy and bone marrow involvement was observed, and the pathologic diagnosis of the cervical lymph node was identical with that of the duodenal lesion.     

Eradication rates of helicobacter pylori infection with second-line treatment: non-ulcer dyspepsia compared to peptic ulcer disease

BACKGROUND/AIMS: Initial proton pump inhibitor (PPI)-based triple therapy for Helicobacter pylori (H. pylori) infection is less effective in patients with nonulcer dyspepsia (NUD) than those with peptic ulcer disease (PUD). To date, there have been no studies on the difference in eradication rates in NUD compared to PUD with regard to second-line therapy. Therefore, we retrospectively analyzed the difference in eradication rates of a second-line quadruple therapy for NUD and PUD patients. METHODOLOGY: Between June 2003 and December 2005, patients who failed to respond to initial PPI-based triple therapy, received 7 days of quadruple therapy (PPI b.i.d., bismuth 300mg q.i.d., metronidazole 500mg t.i.d., tetracycline 500mg q.i.d.) as a second-line treatment regimen. Four weeks after the completion of the course of medication, a 13C-urea breath test was performed for detection of H. pylori. RESULTS: A total of 87 patients received second-line quadruple therapy. Of these, 43 patients had NUD and 44 patients had PUD (19 gastric ulcers, 23 duodenal ulcers, 2 both ulcers). The eradication rates were 76.7% (33/43) in the NUD group and 90.9% (40/44) in the PUD group by per-protocol analysis. Therefore, the eradication rates in the NUD group were significantly lower than those in the PUD group (p = 0.034). CONCLUSIONS: A 7-day bismuth-based second-line quadruple therapy for H. pylori infection was less effective in patients with NUD than those with PUD. Therefore, a more potent second-line treatment regimen or extension of treatment duration of quadruple therapy should be considered for the eradication of H. pylori in patients with NUD.     

10 Eradication of Helicobacter pylori

Although there are numerous publications reporting eradication results, the general picture is confused by the bewildering multiplicity of treatment schedules employed by the various workers. The over-riding need now is for large scale trials, and more especially for direct comparisons of different treatment regimens in the same populations of patients. Such data are entirely absent from the literature at present. Standardization of definitions and of methodology pertaining to diagnosis of eradication, recording of side effects, measurement of compliance and determination of recurrence or of reinfection, is badly needed. As the definition of eradication remains arbitrary, it is important to include genome fingerprinting techniques in the long-term follow-up for recurrence, so that the question of reinfection versus recrudescence can be examined (Bell et al, 1993b; Xia et al, 1994).Because of the wide differences in the agents used in H. pylori eradication therapies, proper double-blinding of treatment trials remains a difficult problem. This can be dealt with to some extent by ensuring that the interpretation of tests for H. pylori eradication is performed by personnel unaware of the clinical details.Review of the existing data on eradication of H. pylori indicates that clinically useful results can be achieved in some 70 to 95% of patients, on an intention to treat basis. Compliance, side effects and resistance to metronidazole remain the limiting factors. Efficacy, freedom from side effects, simplicity and low cost will determine the success of any regimen in the future. At present, it is not possible to make firm recommendations in favour of one regimen over another, but it seems reasonable to forecast that dual therapies consisting of a PPI and an antibiotic will receive much attention. Preparations consisting of an H₂RA associated with a bismuth compound, which are used together with an antibiotic are an interesting approach. Compliance should be as good as with a normal dual therapy and the eradication results look promising (Wyeth et al, 1994; Webb et al, 1994).The advantages of dual therapies that include a PPI lie in their simplicity, in not relying on imidazole for their anti-H. pylori effect but on the profound inhibition of acid output produced by the PPI. Thus PPI based dual therapy can probably evoke better compliance than the more complicated regimens.The use of PPIs has other advantages in addition to decreasing the MIC₉₀ of the antibiotic combined with it. This is because administration of a powerful inhibitor of gastric acid secretion, such as a PPI, will aid the rapid healing of an ulcer crater and will rapidly relieve the symptoms of peptic ulceration. Gastrin releasing peptide-stimulated acid secretion is raised in duodenal ulcer patients to approximately sixfold over control levels according to El-Omar et al (1993b), and although it returns to normal following the eradication of H. pylori, this process takes time to become effective (El-Omar et al, 1993a). Suppression of acid output provides an immediate therapeutic shield, while the decrease in inflammation and acid output secondary to H. pylori eradication can be established.The most widespread resistance to antibiotics exhibited by H. pylori is with respect to imidazoles. The prevalence of metronidazole resistance is widespread in the emergent countries (Glupczynski et al, 1990), but it is also appreciable in the West, especially in women, who may have been given metronidazole in the treatment of pelvic infections (Rautelin et al, 1992; Banatvala et al, 1994). Moreover, H. pylori becomes resistant to metronidazole very easily and often as a result of treatment which includes an imidazole compound (Malfertheiner, 1993; Banatvala et al, 1994). On the other hand, H. pylori resistance to macrolides is not widespread and does not develop easily during their administration. It is difficult to forecast which antibiotic will be the most widely used agent in combination with a PPI. Amoxycillin seems quite effective when combined with a PPI administered twice daily, while clarithromycin leads the macrolides in its in vitro anti-H. pylori activity.Bismuth-based triple regimens have the advantage of familiarity. Ensuring compliance is the duty of the physician initiating the treatment. The incidence of eradication with these regimens differs in different centres (Logan et al, 1991a; Bell et al, 1993a) and the reasons for these discrepancies need to be investigated.One week, low dose triple therapy with omeprazole, clarithromycin and tinidazole or metronidazole appears highly effective, with few side effects and good compliance (Bazzoli et al, 1994; Jaup and Norrby, 1994; Moayyedi and Axon, 1994; Labenz et al, 1995). However, data is not available on the pretreatment sensitivity to nitroimidazoles of H. pylori from the patients studied, or of the development of resistant strains during treatment. Further studies are needed to confirm these encouraging results in different populations and with pre-treatment H. pylori sensitivities.The ideal regimen for the eradication of H. pylori does not exist at present. Moreover, note has to be taken of epidemiology of the bacterium in different parts of the world. Eradication strategies may be confounded in the emergent countries, where prevalence and resistance patterns to antibiotics are so different from the first world.     

Eradication of hantavirus infection among laboratory rats by application of caesarian section and a foster mother technique.

Hantavirus antibodies were demonstrated by the indirect immunofluorescent antibody assay, in the serum of inbred strains of laboratory rats, during the period 1973-1982, at the Unit of Experimental Immunology in the Catholic University of Louvain, Brussels, Belgium. LOU rats, as well as immunocytomas, which were requested by laboratories in the U.K. and The Netherlands, were supplied at a time when the infection was unknown and unsuspected in Europe. Hantavirus-infected laboratory rats were rendered free of virus through re-derivation by caesarian section and suckling by virus-free foster mothers. Immunocytomas were tested for the presence of hantaviruses by implantation into seronegative laboratory rats. The strain of hantavirus causing the laboratory infection was clearly different from the one circulating in free-living bankvoles in Belgium. The exchange of laboratory rats and rat tumours in relation to the potential risk of laboratory-acquired hantavirus infection, is discussed.     

雷、环、痢方案根治幽门螺杆菌感染临床疗效观察(附134例报告)

目的　观察雷尼替丁、环丙沙星、痢特灵三联对幽门螺杆菌 (Hp)阳性的消化性溃疡、慢性胃炎患者的Hp根除率及对消化性溃疡的治疗效果。方法　经快速尿素酶试验及胃粘膜活检均确认有Hp感染的消化性溃疡、慢性胃炎患者共 15 5例 ,用雷尼替丁、环丙沙星、痢特灵三联与改良的经典三联 (果胶铋、四环素、痢特灵 )作随机对照治疗。治疗组进入临床试验病例 79例 ,疗效评价 6 8例。对照组进入试验病例 76例 ,疗效评价 6 6例。结果　治疗组与对照组Hp根除率分别为 88 2 % ( 6 0 /6 8)与 84 8% ( 5 6 /6 6 )。消化性溃疡临床愈合率分别为 81 7%与 6 5 6 % ,总有效率分别为 97 2 %与81 3 %。不良反应发生率分别为 4 4%与 14 9% ,上述结果经统计学比较Hp根除率两组差异无显著性 (P >0 0 5 ) ,消化性溃疡愈合率及总有效率、不良反应发生率差异有显著性 (P <0 0 5 )。结论　雷尼替丁、环丙沙星、痢特灵三联为一效好、价廉、不良反应少的治疗方案。     

Eradication of H pylori infection in a rural population： One-day quadruple therapy versus 7-day triple therapy

AIM: To compare the one-day quadruple therapy with a standard 7-d triple therapy for H pylori eradication in a rural population of China. METHODS: A total of 396 patients with 13C-urea breath test positive for H pylori were assigned into two groups: 239 patients received one-day quadruple therapy (amox icillin 2000 mg qid; metronidazole 500 mg qid; bismuth citrate 900 mg qid and lansoprazole 60 mg once daily) and 157 patients received 7-d standard triple therapy (amoxicillin 1000 mg bid; clarithromycin 500 mg bid and lansoprazole 30 mg bid). All the patients underwent a 13C-UBT to assess the eradication of H pylori infection six weeks after treatment. RESULTS: Two hundred and twenty-nine patients completed the one-day therapy (95.8%) and 148 patients completed the 7-d therapy (94.2%). The one day therapy eradicated H pylori infection in 64 patients (27.95%). In contrast, 103 patients (69.59%) were H pylori negative after the 7-d therapy (P < 0.01). CONCLUSION: This pilot study suggests there is no beneficial effect of the one-day therapy in treatment of H pylori infection compared with the 7-d standard therapy.