小腸潰瘍を認めたIgG4関連疾患の1例

IgG4-related Disease with Small Intestinal Lesions, Report of a Case

要旨●50歳代，男性．4年前から持続する慢性下痢にて近医を受診し，γグロブリン高値，M蛋白陽性，補体の低下があり，当院膠原病内科の検査ではIgG 4,778mg/dl，IgG4 2,910mg/dlと高値だった．経過中に腹痛で当院救急外来へ受診して入院した．慢性下痢に加え，CTにて近位小腸の壁肥厚があり，上・下部消化管内視鏡検査，経口ダブルバルーン小腸内視鏡検査を施行したところ，空腸，回腸の生検でIgG陽性形質細胞中のIgG4陽性細胞の割合が6割以上とIgG4関連疾患の定義を満たす病理所見が得られた．本症例は診断後ステロイド治療にて速やかに寛解した．慢性下痢を呈する症例ではIgG4関連疾患も鑑別に挙がると考えられた．

　A 50-year-old man presented to our hospital with abdominal pain and chronic diarrhea. He was admitted because of worsening of his abdominal pain. His blood tests revealed elevated C-reactive protein as well as IgG and IgG4 levels. Esophagogastroduodenoscopy and colonoscopy findings revealed multiple erosions and ulcerations in the patient's stomach and colon. Furthermore, abdominal computed tomography findings revealed increased bowel wall thickness in the proximal small intestine. Small erosions and irregular ulcerations were observed in the jejunum, whereas no inflammation was observed in the ileum. Histological findings from biopsy specimens revealed infiltration of inflammatory cells, including plasma cells, in the jejunum, with the percentage of IgG4-positive plasma cells being >60%. The patient responded immediately to steroid therapy. IgG4-related disease should be included in the differential diagnosis in cases of continuous unexplained chronic diarrhea.