サイトメガロウイルス腸炎

Cytomegalovirus Enterocolitis

要旨　サイトメガロウイルス（CMV）腸炎の臨床像について述べた．CMV腸炎は増加しており，多くは免疫不全の患者に生じる．症状は下血・血便と下痢が多く，小腸病変を主とする場合は穿孔や下血が多い．診断にはCMV antigenemiaの測定や組織核封入体の検出，免疫組織化学による組織CMV抗原の検出が有用である．しかし，これらが陰性でもCMV腸炎が疑わしい場合は，血中と組織中のPCRによるDNAの測定を行う必要がある．内視鏡所見は打ち抜き様潰瘍が最も多いが，浅い不整形潰瘍，輪状傾向潰瘍，帯状潰瘍，縦走潰瘍，アフタ様潰瘍などもみられる．治療はganciclovirを用いるが，その効果は宿主の免疫能に依存する．

　Clinical features of cytomegalovirus（CMV）enterocolitis are described in this paper. The incidence of CMV enterocolitis has been rising in recent years. It often develops in immunocompromised hosts. Frequent signs and symptoms of CMV enterocolitis include bloody stool and diarrhea. Perforation and bloody stool are often observed in cases of CMV enterocolitis primarily affecting the small bowel. CMV antigenemia assay and detection of CMV inclusion bodies in biopsy specimens from the gastrointestinal mucosa（by either hematoxylin ＆ eosin staining or immunohistochemistry using anti-CMV monoclonal antibodies）are useful in diagnosing this condition. Polymerase chain reaction assay to detect CMV-DNA in blood and tissue is required in cases in which these tests are negative but CMV enterocolitis cannot be ruled out. Although punched-out ulcer is the most frequent endoscopic finding in cases of CMV enterocolitis, shallow irregular ulcers, annular-like ulcers, belt-shaped ulcers, longitudinal ulcers, aphthoid ulcers, and other lesions are also occasionally seen. Ganciclovir is used to treat this condition, though responses to it depend on host immune function.