Pyloric metaplasia (PM) and pseudopyloric metaplasia (PPM) are metaplastic changes resulting in pyloric-type glands in the gastric oxyntic mucosa that mainly occur in chronic gastritis caused by Helicobacter pylori (H. pylori) infection. Focusing on PM and PPM, we classified the histological changes in gastric mucosa according to the Updated Sydney System, using 314 biopsy specimens of gastric greater curvature of the middle body before H. pylori eradication (HPE). Next, the numbers of PM and PPM glands were counted in 47 specimens, and subjects were followed up over 10 years after HPE. PPM was recognized jointly with inflammation, activity, atrophy, and intestinal metaplasia, but PM was recognized more frequently than PPM as atrophy and intestinal metaplasia progressed. Both PM and PPM regressed significantly within 6 years after HPE. Additionally, we demonstrated that PM and PPM are not always coincident with spasmolytic polypeptide-expressing metaplasia (SPEM). In conclusion, PM and PPM are considered different modulations of the same line of differentiation, which are both reversible, with PM potentially emerging from PPM upon progression.

中文翻译：

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幽门螺杆菌根除后幽门和假幽门化生相关的组织学变化。

幽门化生（PM）和假性幽门化生（PPM）是化生性变化，导致胃氧化性粘膜的幽门型腺体主要发生在幽门螺杆菌（H. pylori）感染引起的慢性胃炎中。着重于PM和PPM，我们根据更新的Sydney System对胃黏膜的组织学变化进行了分类，使用了314例幽门螺杆菌根除前胃中曲度较大的胃活检标本。接下来，对47个标本中的PM和PPM腺进行计数，并在HPE后10年内对受试者进行随访。PPM与炎症，活动，萎缩和肠上皮化生有关，但随着萎缩和肠上皮化的发展，PM较PPM更为常见。HPE后6年内，PM和PPM均显着下降。此外，我们证明了PM和PPM并不总是与表达痉挛性多肽的化生（SPEM）一致。总之，PM和PPM被认为是同一分化线的不同调制，两者都是可逆的，随着进展，PM可能会从PPM中出现。