Post H. pylori時代の胃炎・胃症の病理

Pathology of Gastritis and Gastropathy in the Post-Helicobacter pylori Era

要旨●H. pyloriの感染率の低下と除菌療法の普及によりPost H. pylori時代が到来したと言われている．慢性活動性胃炎が減少し，除菌療法やプロトンポンプ阻害薬（PPI）の普及によりこれまでみたことのなかった内視鏡像と病理組織像が日常的に観察されるようになり，本邦ではまれな疾患とされてきた自己免疫性胃炎の診断が一般化してきた．Post H. pylori時代と言っても，胃炎の正確な病理診断に至るためには，H. pyloriの感染状況（未感染，現感染，既感染）の情報抜きの胃炎診断はできない．これを含む必要十分な臨床情報と内視鏡所見を踏まえて，生検部位とその部位での正常組織像との対比を考慮しつつ，一枚の生検組織内にみられる種々の病理所見を丁寧に観察し，頻度の高い胃炎（ABC胃炎）からその他の（比較的まれな）胃炎へと診断を流れるように進めていく，胃炎・胃症の病理診断における思考過程を解説する．

　With the current decrease in Helicobacter pylori infection rates and the widespread use of eradication therapy, we have entered the post-H. pylori era. The decline in chronic active gastritis, combined with the frequent use of eradication therapy and proton pump inhibitors, has led to common endoscopic and histopathological findings that were previously unseen. Consequently, the diagnosis of autoimmune gastritis, once considered rare in Japan, has become more common. Even in the post-H. pylori era, accurately diagnosing gastritis requires information on the patient's H. pylori infection status（uninfected, currently infected, or previously infected）. Based on comprehensive clinical and endoscopic findings, including the abovementioned information, it is crucial to carefully examine various pathological findings in biopsy specimens. This involves comparing the histology of the biopsy site with the normal tissues at that location. The diagnostic approach should flow from the most common type of gastritis（ABC gastritis）to other, relatively rare forms. This chapter will explain the thought process in the pathological diagnosis of gastritis and gastropathy.