The Korean Journal of Helicobacter and Upper Gastrointestinal Research最新文献

In 2013, the Japan Gastroenterological Endoscopy Society introduced the Kyoto classification of gastritis, which is useful to predict Helicobacter pylori infection based exclusively on endoscopic findings. Based on the Kyoto classification of gastritis, gastric mucosal atrophy, endoscopic intestinal metaplasia, hypertrophic gastric folds, nodularity, and diffuse redness may be associated with gastric cancer and H. pylori infection, which are common endoscopic findings in Koreans. Atrophy and intestinal metaplasia are associated with gastric cancer and therefore require attention. Hypertrophic gastric folds, nodularity, and diffuse redness can be associated with current H. pylori infection. The Kyoto scoring system, which is based on endoscopic findings is useful to predict current H. pylori infection and gastric cancer in the absence of biopsy evaluation in clinical settings. A therapeutic strategy for H. pylori infection based on the Kyoto score is expected to reduce the incidence of gastric cancer in Korea and Japan. In this study, we investigated the endoscopic findings commonly observed in Koreans among those defined by the Kyoto classification of gastritis.

Background/aims: Compared with other regimens, concomitant therapy (CT) used as a first-line regimen for Helicobacter pylori (H. pylori) infection is associated with higher eradication rates. We compared the efficacy of tailored therapy (TT) using bismuth added to standard triple therapy (STT) with CT.

Methods: This consecutive study performed between September 2020 and 2021 included 210 patients with H. pylori infection. Two participating gastroenterologists prescribed TT and CT. Multiplex PCR assays were performed before eradication therapy to identify the relevant point mutations and confirm clarithromycin resistance in the TT group (n=105). Patients who showed negative PCR results received 14-day STT and those with positive PCR results received a 14-day regimen of bismuth added to STT. The other group (n=105) received 10-day CT.

Results: Based on per-protocol analysis, eradication rates in the TT and CT groups were 89.2% (91/102) and 81.6% (84/103), respectively. We observed no statistically significant intergroup differences in eradication rates (P=0.12). The frequency of estimated clarithromycin resistance confirmed using multiplex PCR assays was 32.4% (34/105), and the eradication rate associated with bismuth add-on STT was 76.5% (26/34) in patients with clarithromycin resistance.

Conclusions: Considering the current and emerging trends in antibiotic resistance, a therapeutic strategy using TT (bismuth add-on STT) is recommended to minimize unnecessary administration of antibiotics.

Gastritis is common worldwide. The combination of Helicobacter pylori (H. pylori) infection with background gastritis, including atrophic gastritis or intestinal metaplasia is implicated as an important etiopathogenetic contributor to gastric cancer. Since the gastritis classification proposed by Schindler, research has focused on classification of gastritis for accurate diagnosis and prediction of prognosis. Advances in endoscopic technology have enabled more accurate visualization of the gastric mucosa and 'targeted' biopsies with the emergence of newer classifications based on visual findings (Kimura-Takemoto classification) and more specific histopathological findings using targeted biopsies (Whitehead classification). Following the discovery of H. pylori, it is mandatory to consider its role as an important contributor to gastritis. Therefore, it was necessary to redefine the classification of gastritis and arrive at a consensus, which led to the establishment of an international consensus classification, referred to as the Sydney system. However, the Sydney system alone cannot predict the gastric cancer risk, and scoring systems such as the Operative Link for Gastritis Assessment and the Operative Link on Gastritis Assessment based on Intestinal Metaplasia were proposed. These systems are based on histopathological findings observed in endoscopic biopsy specimens. However, availability of high-definition images following technological advances has facilitated the emergence of a visual classification, the Kyoto classification. In contrast to the Sydney system, the Kyoto classification is based exclusively on interpretation of visual findings and focuses on detection of H. pylori infection and gastric cancer prediction. In this review, we summarize the history and background of the various classifications of gastritis.

The gastric cancer risk varies based on the etiology and severity of gastritis, which depends on a history of Helicobacter pylori infection and the secretory capacity of the stomach. Type A gastritis is associated with reverse atrophy of the corpus and type B with progressive atrophy extending from the antrum to the corpus. Diffuse or spotty redness in the corpus together with high serum pepsinogen (PG) II levels and a low PG I/II ratio are observed in patients with H. pylori infection when secretory capacity of the stomach is intact. Diffuse-type gastric cancer may develop near the gastric folds, which is a rare site of atrophy. Low serum PG I levels are associated with progressive gastric corpus atrophy and intestinal metaplasia in patients with chronic and previous H. pylori infections. This clinical scenario predisposes patients to intestinal-type gastric cancer, which originates in the atrophic and metaplastic gastric mucosa. Conversely, a high PG I/II ratio is observed in patients without H. pylori infection. Serum PG I levels and the PG I/II ratio are high in patients with acute H. pylori-negative gastritis, including drug-induced gastritis but are significantly low in autoimmune gastritis. Gastric neuroendocrine tumors may develop in patients with autoimmune gastritis or in those with long-term acid suppressant use. Fasting serum gastrin levels and the risk of neuroendocrine tumors are high in both cases. In this review, types of gastritis are summarized along with evaluation performed to determine the secretory capacity of the background gastric mucosa.

Autoimmune gastritis (AIG), a chronic inflammatory disease occurs as a result of a complex interaction between host-related and environmental factors. AIG may progress to severe atrophic gastritis secondary autoimmune-mediated parietal cell destruction in the stomach. AIG can be diagnosed based on anti-parietal cell antibody tests and endoscopy, which reveals widespread gastric corpus atrophy in patients with low serum pepsinogen I levels, a low pepsinogen I/II ratio, and elevated serum gastrin levels on serological testing. Tissue biopsy findings, which include mucosal atrophy and lymphocytic infiltration of the lamina propria may be useful for diagnostic confirmation. Decreased gastric acid secretion causes hypergastrinemia and enterochromaffin-like (ECL) cell proliferation, which can lead to neuroendocrine tumor development. Additionally, an autoimmune response results in parietal and chief cell injury, and proliferating ECL cells are detected in the deep mucosal layers in patients with AIG. Therefore, this condition may easily be misdiagnosed as a subepithelial tumor, and establishing a differential diagnosis for other types of subepithelial tumor accompanied by AIG is challenging. We present the case of a 54-year-old woman who was diagnosed with AIG with a concomitant subepithelial tumor based on serologic tests and biopsy findings and underwent wedge resection, which confirmed diagnosis of a schwannoma.

Background/aims: Standard triple therapy (STT; proton pump inhibitor [PPI]+clarithromycin+amoxicillin) used for Helicobacter pylori (H. pylori) eradication has shown low treatment success rates in recent years, which is most likely attributable to increased clarithromycin resistance. In this study, we compared treatment success rates of tailored therapy (TT) using real-time polymerase chain reaction (RT-PCR) and empirical STT.

Methods: This retrospective study included 650 patients with H. pylori infection, who visited Eunpyeong St. Mary's Hospital in Korea; 343 patients received TT based on RT-PCR assays, and 307 patients received STT. Eradication success was defined as a negative ¹³C-urea breath test result 4~8 weeks after treatment completion. Patients who failed first-line therapy and those with clarithromycin resistance received bismuth-containing quadruple therapy (BQT; PPI+bismuth+metronidazole+tetracycline).

Results: Intention-to-treat analysis showed that H. pylori eradication rates were higher in patients who received RT-PCR-based TT than in those who were treated using empirical STT (80.5% [190/236] vs. 70.4% [216/307], P=0.069). Per-protocol (PP) analysis showed similar results (84.4% [190/225] vs. 74.7% [216/289], P=0.007). PP analysis showed that 7-day TT treatment was associated with a higher eradication rate than that observed with 10- to 14-day STT (85.2% [178/209] vs. 73.8% [59/80], P=0.029). The clarithromycin resistance rate was 27.9% (87/312). The eradication success rate was 89.2% (74/83) in patients with clarithromycin resistance, who received BQT as first-line therapy.

Conclusions: The treatment success rate was higher in patients who received 7-day RT-PCR-based TT than in those who were administered 10- to 14-day empirical treatment.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type of extranodal non-Hodgkin lymphoma. Endoscopic findings are nonspecific and variable; therefore, differentiation of this malignancy from early gastric cancer is challenging during endoscopy. Although an endoscopic biopsy is the gold standard for diagnosis, a biopsy may not conclusively establish the diagnosis in all cases. Diagnostic confirmation requires interpretation of the biopsy specimen findings by an experienced histopathologist, and an additional immunoglobulin heavy chain (IgH) rearrangement test may aid with accurate diagnosis. We present a case of gastric MALT lymphoma that histopathologically mimicked signet ring cell carcinoma (SRCC) on evaluation of repeat endoscopic biopsies. Following endoscopic submucosal dissection (ESD), we confirmed the final diagnosis of gastric MALT lymphoma based on histopathological findings of prominent lymphoid infiltrates accompanied by lymphoepithelial lesions and results of the monoclonal IgH rearrangement test. Notably, a few carcinoma-like signet ring cells (SRCs) in the specimen were attributed to a reactive change. Clinicians should be mindful of possible SRCs in gastric MALT lymphoma specimens to avoid misdiagnosis of SRCC in patients with gastric MALT lymphoma. Confirmatory ESD may be useful for accurate diagnosis and appropriate management of such lesions.