Helicobacter pylori陽性と陰性の胃粘膜所見の特徴―内視鏡所見

Characteristics of Helicobacter pylori-Positive and -Negative Gastric Mucosa Findings

要旨　通常内視鏡による胃粘膜の観察で，どのくらいHelicobacter pylori（H. pylori）の存在が診断可能か検討した．従来から言われている“まだら模様”胃粘膜，胃体部大彎の粘膜皺襞の肥厚・蛇行，粘液付着，びまん性発赤および鳥肌状胃粘膜をH. pylori陽性所見とし，胃体部の“鳥の足”様微細血管所見（regular arrangement of collecting venules ; RAC）をH. pylori陰性所見とした．内視鏡によるH. pyloriの陽性・陰性の診断率は72.5％であった．所見別に検討するとRAC陽性ではH. pylori陰性が95.1％であり，RACはH. pylori陰性を示唆する重要な所見である．しかし，RAC陽性は必ずしも胃全体のH. pylori陰性を示すものではなく，その局所粘膜のH. pylori陰性を表現するものである．胃底腺ポリープ，表層性胃炎などの場合 RAC を認めることが多い．

　A study was conducted to ascertain the degree to which the presence of Helicobacter pylori (H. pylori) can be diagnosed by observation of the gastric mucosa during a conventional endoscopic examination. A mottled gastric mucosa, thickening or contortion of the membranous folds of the greater curvature of the stomach body, mucus adherence, diffuse redness and gastric mucosa with a miliary pattern resembling chicken-skin are conventionally accepted H. pylori-positive findings. Microvessel pattern resembling a bird's foot (RAC : regular arrangement of collecting venules) is a H. pylori-negative finding. The H. pylori-positive/negative diagnosis rate with endoscopic examination was 72.5％. By findings, with a positive RAC finding, the H. pylori-negative rate was 95.1％, indicating that RAC is an important finding suggesting the absence of H. pylori infection. However, RAC-positive findings do not necessarily indicate that H. pylori is absent from the entire stomach. Rather, it is an indication that localized areas of the mucosa are H. pylori-negative.

　RAC is observed in many cases of fundic gland polyp, superficial gastritis and other diseases.