Distribution of CagA in gastric phenotype.

Background
Helicobacter pylori (H. pylori) is frequently associated with non-cardia type gastric cancer, and it is designated as a group I carcinogen. This study aimed to systematically review and meta-analyze the evidence on the prevalence of CagA status in people with gastric disorders in the Indo-Pacific region, and to examine the association of CagA positive in the risk of gastric disorders. This study focused on the Indo-Pacific region owing to the high disability adjusted life-years related to these disorders, the accessibility of efficient treatments for this common bacterial infection, and the varying standard of care for these disorders, particularly among the elderly population in the region.
Methods
Relevant studies were identified in the health-related electronic databases including PubMed, Ovid, Medline, Ovid Embase, Index Medicus, and Google Scholar that were published in English between 1 January 2000, and 18 November 2023. For pooled prevalence, meta-analysis of proportional studies was done, after Freeman-Tukey double arcsine transformation of data. A random-effect model was used to compute the pooled odds ratio (OR) and 95% confidence interval (CI) to investigate the relationship between CagA positivity and gastric disorders.
Results
Twenty-four studies from eight Indo-Pacific countries (Bhutan, India, Indonesia, Malaysia, Myanmar, Singapore, Thailand, Vietnam) were included. Overall pooled prevalence of CagA positivity in H. pylori-infected gastric disorders was 83% (95%CI = 73–91%). Following stratification, the pooled prevalence of CagA positivity was 78% (95%CI = 67–90%) in H. pylori-infected gastritis, 86% (95%CI = 73–96%) in peptic ulcer disease, and 83% (95%CI = 51–100%) in gastric cancer. Geographic locations encountered variations in CagA prevalence. There was a greater risk of developing gastric cancer in those with CagA positivity compared with gastritis (OR = 2.53,95%CI = 1.15–5.55).
Conclusion
Findings suggest that the distribution of CagA in H. pylori-infected gastric disorders varies among different type of gastric disorders in the study countries, and CagA may play a role in the development of gastric cancer. It is important to provide a high standard of care for the management of gastric diseases, particularly in a region where the prevalence of these disorders is high. Better strategies for effective treatment for high-risk groups are required for health programs to revisit this often-neglected infectious disease.

背景
幽门螺杆菌（Helicobacter pylori，简称H. pylori）与非贲门型胃癌密切相关，已被列为I类致癌物。本研究旨在对印太地区胃部疾病患者中细胞毒素相关蛋白A（CagA）的流行情况证据进行系统综述与荟萃分析，并探讨CagA阳性与胃部疾病发病风险的关联。本研究聚焦印太地区的原因在于：该类疾病相关伤残调整寿命年（disability adjusted life-years）较高，这种常见细菌感染已有高效治疗手段可及，且该地区（尤其是老年人群）的胃部疾病诊疗标准存在差异。
方法
本研究检索了2000年1月1日至2023年11月18日期间发表的英文文献，检索数据库包括PubMed、Ovid、Medline、Ovid Embase、Index Medicus及Google Scholar等医学电子数据库。针对合并流行率，研究采用Freeman-Tukey双反正弦变换对数据进行处理后，开展比例研究的荟萃分析。本研究采用随机效应模型计算合并比值比（odds ratio, OR）及95%置信区间（confidence interval, CI），以探讨CagA阳性与胃部疾病的关联。
结果
本研究共纳入来自印太地区8个国家（不丹、印度、印度尼西亚、马来西亚、缅甸、新加坡、泰国、越南）的24项研究。幽门螺杆菌感染相关胃部疾病患者的CagA阳性总体合并流行率为83%（95%CI=73–91%）。分层分析显示，幽门螺杆菌感染性胃炎患者的CagA阳性合并流行率为78%（95%CI=67–90%），消化性溃疡病患者为86%（95%CI=73–96%），胃癌患者为83%（95%CI=51–100%）。不同地理区域的CagA流行率存在差异。与胃炎患者相比，CagA阳性者罹患胃癌的风险更高（OR=2.53，95%CI=1.15–5.55）。
结论
本研究结果表明，印太地区各国幽门螺杆菌感染相关胃部疾病患者的CagA分布因胃部疾病类型不同而存在差异，CagA可能在胃癌发生发展中发挥作用。鉴于该地区胃部疾病高发，为胃部疾病患者提供高标准诊疗至关重要。卫生健康项目亟需优化高危人群的有效治疗策略，以重新关注这一常被忽视的感染性疾病。