Significance of Helicobacter heilmannii infection after Helicobacter pylori eradication

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K09361
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Gastroenterology
• Research Institution: Kitasato University
• Principal Investigator: Nakamura Masahiko 北里大学, 薬学部, 研究員 (30155858)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: NHPH / Helicobacter suis / Helicobacter heilmannii / PCR / 免疫組織化学 / 鳥肌胃炎 / 胃MALTリンパ腫

Outline of Final Research Achievements

The clinical significance of non-Helicobacter pylori Helicobacter (NHPH) is still unknown. There are many reports of NHPH-infected patients suffering from gastric diseases. Here we investigated the polymerase chain reaction (PCR) positivity of NHPH infection in gastric disease patients who were negative for Helicobacter pylori (Hp). Materials and Methods: We collected the 296 gastric mucosal samples of Hp-negative gastric disease patients from 17 hospitals in Japan from Sept 2013 to June 2019, and analysed the existence of Hp and NHPH by PCR. Results: Among the 236 non-Hp-eradicated cases, 49 cases (20.8%) were positive for NHPH. In all of these cases the NHPH diagnosed by PCR was successfully eradicated. I Among the 29 post-Hp eradication cases, three were NHPH-positive. Thus, approx. 20% of the Hp negative non-Hp-eradicated gastric disease patients treated at 17 hospitals in Japan were infected with NHPH.

Free Research Field

NHPHの疫学、病態解析および治療法

Academic Significance and Societal Importance of the Research Achievements

我々は、10年以上にわたりNHPHの特徴、疾患形成との関連についての検討をカニクイザルおよびヒト由来菌のマウス感染モデルを用いて行ない、ピロリ菌との混合感染ではなくピロリ菌陰性者にNHPH感染例が多いことを見出した。今回の検討でも、さらに明確に認められたことから、ピロリ菌陰性の胃MALTリンパ腫、鳥肌胃炎、慢性胃炎、胃十二指腸潰瘍の20%にNHPHが関与することが明らかとなった。さらに、除菌後Hp陰性の症例で胃疾患が認められる場合、その10%にNHPHが陽性であることが示された。一方、除菌療法との関連ではHpと同様の薬剤の組み合わせによる除菌療法で全例が陰性化し、診断の重要性が明らかとなった。