Second-line eradication therapy for H. pylori infection

The widespread use of eradication therapy for Helicobacter pylori has lead to an increase in antibiotic-resistant strains and the problem of retreatment in cases of eradication failure. Retreatment in cases of eradication failure has achieved relatively good results with regimens containing bismuth compounds and tetracyclines in the world, but consensus has not been reached in Japan and each institution has its own policy. An triple therapy consisted of proton pump inhibitor, amoxicillin and metronidazole has been reported to show a good cure rate as a second line therapy in Japan, but metronidazole has not been approved by the Japanese regulatory authority for use against bacterial infections, including H. pylori, despite its worldwide use as an antimicrobial agent in H. pylori eradication regimens.     

Indication of H. pylori eradication therapy

In the guideline, for H. pylori the Japanese Society of Helicobacter published diagnosis and treatment in July 2000. Only peptic ulcers and low grade MALT lymphomas are recommended as an indication of H. pylori eradication and other diseases such as atrophic gastritis, post EMR state for early gastric cancer and post-operated stomach due to gastric cancer, hyperplastic polyps and non-ulcer dyspepsia, were not included. In addition, Japanese social security foundation approves only peptic ulcers for indication of H. pylori eradication treatment. However, eradication therapy for atrophic gastritis should be considered in aspect of decreasing gastric cancer risk. Since accumulated epidemiological, experimental and clinical data strongly support its positive correlation with cancer risk, patients in high risk group for gastric cancer should be included for a target eradication therapy. Indication of the treatment should be expanded to histological gastritis caused by H. pylori in our country, where prevalence of gastric cancer is very high.     

Economic evaluation of H. pylori eradication

A review of economic evaluation studies of Helicobacter pylori eradication was performed. As a result of the high quality and quantity of data emerging, the eradication therapy for patients with gastric or duodenal ulcer was considered to be less costly and more effective than conventional therapy in a Japanese clinical setting. Furthermore, population-based Helicobacter pylori screening was seemed to have the potential to produce important health benefits at a reasonable cost, especially in Japan. Controlled studies are needed to quantify the impact of Helicobacter pylori eradication on the risk of gastric cancer to confirm it.     

Reflux esophagitis after H. pylori eradication

We have reported that prevalence of H. pylori infection and grade of atrophic gastritis were significantly lower, while acid secretion was significantly greater in the patients with reflux esophagitis than those without it. We have also reported that increased gastric acid secretion after H. pylori eradication may explain a reason for developing reflux esophagitis. Therefore, H. pylori is considered to be a protective factor for the development of reflux esophagitis via the induction of gastric hyposecretion. Conversely, according to recent large population-based studies, no evidence was obtained that supports the increased frequency of heartburn symptoms or reflux oesophagitis after the eradication of H. pylori. One reason for the discrepancy may be the difference in the evaluation of gastro-esophageal reflux, another reason may be the difference in acid secretion before the clearance of H. pylori in individual subjects, because the effects of H. pylori on acid secretion vary from patient to patient.     

Proton-pump inhibitors versus H2-receptor antagonists in triple therapy for Helicobacter pylori eradication

Triple therapy with two antibiotics and acid-suppressing drugs is widely accepted for H. pylori eradication. Both H2-receptor antagonist and proton-pump inhibitor are reported to enhance the eradication rate when antibiotics are administered together. Comparative studies using H2-receptor antagonist or proton-pump inhibitor in triple therapy were reviewed. The efficacy of H. pylori eradication regimens with H2-receptor antagonist or proton-pump inhibitor with two antibiotics is not significantly different.     

Suitable diagnostic methods for H. pylori infection after eradication therapy

Urease test, histology, culture, urea breath test(UBT) and stool antigen test are accurate tests for Helicobacter pylori diagnosis. General practitioners are now going to test peptic ulcer disease patients with these tests before and after in Japan. To test with high accuracy after eradication therapy, it is important that examination should be done over 4 weeks after cessation of treatment with PPI and antibiotics. UBT and stool antigen test are suitable tests for diagnosis of Helicobacter pylori infection after treatment.     

Selection of antibiotics and planning of eradication for H. pylori infection

There is general agreement that H. pylori should be eradicated in patients with peptic ulcers. But the optimal therapeutical regimen to be used still remains a matter for many investigations. An increase in the prevalence of antibiotic-resistant H. pylori strains has been reported recently. The recommended drugs for the eradication in Japan are clarithromycin (CAM) and amoxicillin (AMPC) because metronidazole (MNZ) is anti-parasites drug in Japan. A total of 392 H. pylori strains in the last twelve years were tested for sensitivity to CAM, MNZ, and AMPC. The Primary resistance of H. pylori to CAM, MNZ, and AMPC were found in 10.2%, 26.5%, and 0.3% strains, respectively. The resistant strains to CAM were gradually increasing in the last few years. The eradication therapies which do not increase antibiotics resistant strains after eradication failure were reported. The recommendation for eradication in patients with peptic ulcer disease includes those with bleeding ulcers. The pretreatment with proton pump inhibitors (PPI) does not influence the success of PPI-based triple therapy in eradicating H. pylori.     

The significance of H. pylori eradication in NSAIDs ulcer

The significance of H. pylori eradication for NSAIDs induced gastroduodenal ulcer has not been clarified. NSAIDs and H. pylori infection are independent causal factors for gastroduodenal mucosal injuries. However, the interaction between these two factors is complicated. H. pylori eradication can reduce the risk of NSAIDs induced ulcer in NSAIDs naive patients. However, H. pylori eradication is not recommended in NSAIDs user because of no ulcer suppression and ulcer healing delay. In prevention of NSAIDs induced ulcer recurrence, H. pylori eradication plus PPI treatment is necessary.     

Treatment of gastric MALT lymphoma by H. pylori eradication

Strong evidence exists for the efficacy of H. pylori eradication in achieving gastric low-grade MALT lymphoma (L-MALT) regression when the bacteria present. Besides histological evaluation, the appearance of endoscopic finding such as 'discolored mucosa-like atrophy' after treatment may be useful for the prediction of its outcome (endoscopic evaluation). However, a reliable marker for molecular evaluation is not obtained so far. On the other hand, long-term control of L-MALT with H. pylori eradication therapy is uncertain and there still remains a subset of patients with no evidence of H. pylori or who fail H. pylori eradication therapy. Therefore, the optimal non antibiotic therapy for these patients has been studied. According to the recent report, radiation therapy appears to be well tolerated and effective for patients with gastric L-MALT.     

幽门螺杆菌粪便抗原检测法在幽门螺杆菌根除后患者中的效果

目的：探讨幽门螺杆菌（Hp）粪便抗原检测（HpSA）在Hp根除后患者中的效果,为Hp感染患者后期复查提供依据。方法选取该院2011年12月至2013年12月进行Hp根治后的170例患者进行研究,所有患者均进行14C尿素呼气试验检测HpSA,观察HpSA检测Hp的灵敏度和准确率,为Hp感染的检测提供依据。结果与14C尿素呼气试验金标准检测比较,患者治疗1周后,HpSA试验检测灵敏度为78．08％,诊断正确率为68．24％;患者治疗2周后HpSA试验检测灵敏度为74．12％,诊断正确率为54．71％;患者治疗3周后,HpSA试验检测灵敏度为46．38％,诊断正确率为47．65％。结论HpSA检测方法的诊断准确率高、灵敏度高、特异度高、适用于Hp的诊断,尤其适用于儿童、老年患者的筛查及无法开展13C或14C‐尿素呼气试验的贫困地区,且检测值不受患者是否进行治疗的影响。