薬剤に関連するcollagenous colitisの病態と診断

Diagnosis and Clinical Features of Drug-induced Collagenous Colitis

要旨●collagenous colitis（CC）の自験例95例を対象とし，臨床像・薬剤歴・内視鏡像を検討した．95例中75例（78.9％）がプロトンポンプ阻害薬（PPI）服用症例であった．ランソプラゾール（LPZ）起因性CC症例70例中47例（67.1％）はCYP3A4で代謝される薬剤を併用していた．PPI非服用患者は95例中20例（21.1％）で6例は薬剤との関連は不明であった．LPZ起因性CC症例に特徴的とされる縦走潰瘍は，PPI起因性CC症例75例中20例（26.7％）に認められ，全症例がLPZに起因する症例であったが，PPI非服用患者でも20例中4例（20.0％）に認められた．PPI服用群・PPI非服用群間で内視鏡所見の特徴に統計学的差異は認められなかった．下痢症状を呈さず縦走潰瘍所見を契機に病理組織学的にCCと診断された症例を6例認め，2例は急性腹症を呈し4例は無症状であった．慢性下痢症状のみならず，急性腹症を呈する疾患の鑑別のひとつとしてCCを挙げる必要があり，臨床症状に関する診断基準については今後検討を要する．

　We examined the medication history, endoscopic findings, and clinical features of 95 patients diagnosed with collagenous colitis（CC）at our hospital and joint research institutions. Seventy-five patients（78.9%）had a history of proton pump inhibitor（PPI）treatment. Forty-seven of the 70 patients（67.1%）who were taking lansoprazole（LPZ）were receiving concomitant treatment with drugs that were metabolized via cytochrome P-450 monooxygenase 3A4（CYP3A4）. The remaining 20 patients（21.1%）were not administered PPI, although a relation of CC to drugs was unknown in six patients.

　The features of endoscopic findings showed no significant differences between patients treated and not treated with PPI. Longitudinal ulcers that were characteristic of LPZ-induced CC were observed in 20（26.7%）of 75 patients diagnosed with PPI-induced CC. In addition, four patients who had not been treated with PPI also had longitudinal ulcers.

　Six patients had no diarrheal symptoms, including two with severe abdominal pain and four with no symptom of CC. All six patients had longitudinal ulcers detected on endoscopy and were diagnosed with CC on histopathological examination.

　Our study highlights the need for reviewing the existing clinical protocols and diagnostic criteria for CC.