若年者におけるH. pylori感染と内視鏡所見―学校検診の立場から

Endoscopic Findings in High School Students with or without Helicobacter pylori Infection

要旨　学校検診で行った尿中Helicobacter pylori（H. pylori）抗体陽性者のうち，信州大学附属病院を受診した高校生30人を対象にして若年者の内視鏡所見を検討した．全例に対して上部消化管内視鏡検査を行い，同時に生検組織を採取して培養法と鏡検法で二次検診を行った．30例中24例にH. pylori感染を認め，内視鏡所見は鳥肌胃炎とclosed typeの萎縮性胃炎の頻度が高かった．生検組織所見では，1例を除いて腸上皮化生を認めなかった．これに対して，他の6例はH. pylori感染はみられず，そのうち4例は内視鏡所見，生検組織所見とも正常であった．一方，残りの2例はopen typeの萎縮性変化がみられ，血清中H. pylori抗体価が陽性であったことからH. pylori既感染と考えられた．H. pyloriに感染している若年者の胃粘膜萎縮の所見は，日常診療で遭遇するH. pylori陽性の中高年者と比較して明らかに軽度であり，胃癌予防のためには胃粘膜の不可逆的変化が起きる前に除菌治療を行うべきであると考えられた．

　Subjects were 30 students who were shown to be positive by the urine-based ELISA for detection of the antibody to H. pylori（Helicobacter pylori）in high school health screenings and who visited Shinshu University Hospital for further examination of H. pylori infection. All 30 students underwent EGD（esophagogastroduodenoscopy）and biopsy samples were taken to examine their H. pylori status. Twenty-four of them were confirmed to be infected by H. pylori. The most common endoscopic findings of students with H. pylori infection were nodular gastritis and closed-type atrophic gastritis. With one exception, histological findings revealed no evidence of intestinal metaplasia in any of the students. On the other hand,6 of 30 students were found to be not infected by H. pylori. Four of these 6 students without H. pylori infection showed normal endoscopic and histologic findings but the remaining 2 were recognized as open-type atrophic gastritis and were thought to have been infected by it in the past.

　Atrophic changes of gastric mucosa in young people with H. pylori infection were mostly mild compared with those in old people, so eradication therapy for H. pylori infection should be considered for youth before irreversible changes of the gastric mucosa might occur.