Volume 32, Issue 4 pp. 616-620
Case Report

Immune checkpoint inhibitor-induced diarrhea: Clinicopathological study of 11 patients

Shunichi Yanai

Corresponding Author

Shunichi Yanai

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

Corresponding: Shunichi Yanai, Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Uchimaru 19-1, Morioka 020-8505, Japan. Email: [email protected]

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Shotaro Nakamura

Shotaro Nakamura

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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Keisuke Kawasaki

Keisuke Kawasaki

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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Yosuke Toya

Yosuke Toya

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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Risaburo Akasaka

Risaburo Akasaka

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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Tomofumi Oizumi

Tomofumi Oizumi

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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Kazuyuki Ishida

Kazuyuki Ishida

Division of Molecular Diagnostic Pathology, Department of Pathology, School of Medicine, Iwate Medical University, Iwate, Japan

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Tamotsu Sugai

Tamotsu Sugai

Division of Molecular Diagnostic Pathology, Department of Pathology, School of Medicine, Iwate Medical University, Iwate, Japan

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Takayuki Matsumoto

Takayuki Matsumoto

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

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First published: 09 October 2019
Citations: 20

Abstract

We reviewed the records of patients with immune checkpoint inhibitor (ICI)-induced diarrhea during 2015 to 2019. ICI included nivolumab and ipilimumab. There were 11 patients with ICI-induced diarrhea aged 46–81 years (median, 63 years). On colonoscopy, four patients appeared normal, whereas loss of vascularity, erythema, granularity, erosions or ulcerations apparently mimicking ulcerative colitis were found in seven patients. Those seven patients had acute inflammation, cryptitis, crypt abscess and apoptosis, suggestive of ICI-induced colitis. Five of the seven patients were treated with prednisolone, two of whom were resistant to prednisolone and required infliximab. In contrast, none of the four patients without ICI-induced colitis required further treatment. Our observations suggest that diversity exists in the clinical, endoscopic and histological severity of patients with ICI-induced diarrhea. Colonoscopy together with biopsy is inevitable for the diagnosis of ICI-induced colitis, which requires intensive treatment.

Conflicts of Interest

Author T.M. is an Editor-in-Chief of Digestive Endoscopy. Other authors declare no conflict of interest for this article.

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