代表的な免疫異常状態における消化管病変の特徴―消化管GVHD

Gastrointestinal Graft-Versus-Host Disease

要旨　内視鏡検査を施行した同種造血幹細胞移植症例155例を検討した．41例が病理組織学的にGVHDと確定診断され，うち12例は他臓器GVHDを伴わない消化管GVHDであった．上部消化管で31例，下部消化管で19例が診断された．上部消化管では胃，下部消化管では終末回腸・深部結腸での内視鏡的有所見率，GVHD診断率が高かった．内視鏡所見としては，粘膜浮腫，発赤，びらん，潰瘍などを認めた．炎症細胞浸潤をあまり伴わない間質浮腫を反映したびまん性の粘膜浮腫像が高率にみられ，比較的特徴的な所見と考えられた．上部消化管で17例，下部消化管で8例のCMV感染を認めた．うちGVHDを伴わないCMV感染例が6例あり，びまん性粘膜変化を伴わないdiscreteな病変が特徴であった．消化管GVHDの早期診断のみならず，日和見感染との鑑別においても，積極的な内視鏡検査の重要性が示唆された．

　Of 163 patients who underwent allogeneic stem cell transplantation at our institution between October, 2000 and September, 2004, 155 underwent endoscopic examination to determine the etiology of GI symptoms such as nausea, vomitting, anorexia, abdominal pain, diarrhea or bloody stool. We identified 41 patients with histopathological evidence of GI GVHD,31 in the upper GI tract and 19 in the lower GI tract. Twelve of 41 patients of GI GVHD had no skin and/or liver GVHD. Twenty four cases of 31 upper GI GVHD were diagnosed in the stomach. In the lower GI tract, the terminal ileum and proximal colon were the most vulnerable to GVHD. The endoscopic findings consisted of turbidity, erythema, erosions, ulcerations and bleeding. Although these are not characteristic findings of GI GVHD, diffuse mucosal edema and erythema were the most frequent findings. Histological findings of GVHD were found regardless of endoscopic findings. An almost normal mucosa was observed in both the upper and lower GI GVHD groups.

　Seventeen patients had cytomegalovirus (CMV) infections in the upper GI tract and 8 patients had CMV infections in the lower GI tract. CMV infections without GI GVHD were diagnosed in 6 patients. Herpes simplex virus (HSV) infections were diagnosed in the esophagus of 3 patients. One of the 3 patients had no GI GVHD.

　Our findings suggest that endoscopic examination allows easier detection of GI GVHD regardless of the presence of GVHD in other organs, and is essential in the differential diagnosis for CMV/HSV infection in allograft patients.