インターフェロン治療により発症・再発した単純性潰瘍の1例

Developed and Relapsed Simple Ulcer by Interferon Therapy, Report of a Case

要旨　患者は63歳，男性．C型慢性肝炎治療のため前医でINF（Peg-INFα2a）投与後に腹痛，発熱，下痢が出現．CTで回腸終末部に壁肥厚がみられ，回腸炎と診断した．保存治療で軽快し，INFの影響を考え以後投与を見合わせた．しかし7か月後に再度同様の症状が出現し，当科へ紹介となった．大腸内視鏡で回腸終末部に深い下掘れ潰瘍がみられ，画像所見と臨床経過から単純性潰瘍と診断した．栄養療法を行い，症状，検査所見は軽快した．慢性肝炎に対し高い血中濃度が維持されるPEG製剤の使用を避け，INFβ製剤による再治療を行ったところ，5日後に腹痛，発熱，下痢の症状を伴って潰瘍が再燃した．単純性潰瘍の発症・再発にINF投与が関連した症例と考えられた．

　There have been cases of ulcerative colitis, ischemic colitis, eosinophilic enteritis, abscess formation in the ileo-cecal region and multiple ulcers reported as intestinal diseases complicated by interferon therapy and the causes were estimated by immuno-regulation effect and occlusion of microvessels. We report a case of simple ulcer treated by interferon therapy, later relapsed.

　A 63-year-old. patient was admitted to our unit presenting by right lower abdominal pain, fever and diarrhea. He had presented the same symptoms 7 months before and at that time, he was administered interferonαfor C type chronic hepatitis. CT scan showed marked wall thickness and an ulcer in the terminal ileum. Colonoscopy revealed a huge round-shaped deeply undermining ulcer with surrounding redness and edematous mucosa, and multiple oval-shaped ulcers, 5-6mm in size, in the terminal ileum. There were no abnormal colonoscopic findings in the colon. Biopsy specimens taken from the ulcer margin and bottom part revealed non-specific inflammation without epitheloid granuloma, inclusion body and apoptotic body, findings which are consistent with simple ulcer. After being treated by 5-ASA（aminosalicylic acid）and TEN（total enteral nutrition）, the ulcers healed and the patient was discharged.

　Repeated interferron therapy with interferonβand diclofenac were carried out 3 months after discharge and CRP value rose 3 days after, and right lower abdominal pain was presented 5 days after therapy had started. CT scan showed the same findings of wall thickness in the terminal ileum. Colonoscopy revealed the same undermining ulcer in the terminal ileum as before and this time, oval shaped ulcers or circularly arranged shallow ulcers on the haustra folds in the right colon. Biopsy specimens showed the same non-specific inflammation as before. This time, we diagnosed the lesion as relapsed simple ulcer due to interferon therapy and concommitant NSAID（nonsteroidal anti-inflammatory drug）ulcer by dicrofenac. Symptoms and the findings of the patient showed recorery again with the suspension of interferon therapy and enteral nutrition. The patient was followed up in the outpatient and showed a good course of recovery.