P752 A nationwide survey of chronic enteropathy associated with SLCO2A1 gene in Japan

J. Umeno1, Y. Fuyuno1, T. Torisu1, A. Hirano1, M. Esaki2, S. Yanai3, N. Ohmiya4, T. Hisamatsu5, K. Watanabe6, N. Hosoe7, H. Ogata7, F. Hirai8, T. Hisabe9, T. Matsui9, T. Yao10, T. Kitazono1, T. Matsumoto3, CEAS Study Group

1Graduate School of Medical Sciences, Kyushu University, Department of Medicine and Clinical Science, Fukuoka, Japan, 2Saga University Hospital, Department of Endoscopic Diagnostics and Therapeutics-, Saga, Japan, 3Iwate Medical University, Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine-, Morioka, Japan, 4Fujita Health University School of Medicine, Department of Gastroenterology, Toyoake, Japan, 5Kyorin University School of Medicine, Department of Gastroenterology and Hepatology, Mitaka, Japan, 6Hyogo College of Medicine, Department of Intestinal Inflammation Research, Nishinomiya, Japan, 7Keio University School of Medicine, Center for Diagnostic and Therapeutic Endoscopy, Tokyo, Japan, 8Fukuoka University Faculty of Medicine, Department of Gastroenterology, Fukuoka, Japan, 9Fukuoka University Chikushi Hospital, Department of Gastroenterology, Chikushino, Japan, 10Sada Hospital, Gastroenterology, Fukuoka, Japan

Background

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is an autosomal recessive disease caused by mutations in the SLCO2A1 gene which encodes a prostaglandin transporter. It is a rare intractable disease characterised by persistent blood and protein loss due to the small intestinal ulcers. Because CEAS mimics Crohn’s disease (CD) concerning ileal ulcers and stenoses, it is often difficult to distinguish CEAS from CD based on gastrointestinal findings alone. Furthermore, SLCO2A1 gene mutations are also known to cause primary hypertrophic osteoarthropathy (PHO) and some CEAS patients manifest digital clubbing, periostosis, acroosteolysis, and thickened skin as extra-intestinal manifestations. Since little is known about the clinical features of CEAS, we conducted a nationwide survey in Japan.

Methods

All study participants provided written informed consent for genetic analysis. The present study was approved by the ethics committee of each institution. During the period between 2012 and 2019, 141 patients suspected of CEAS were enrolled in this study and checked to have SLCO2A1 gene mutations. We reviewed the clinical information of genetically confirmed CEAS patients.

Results

We confirmed 61 CEAS patients (21 males and 40 females) and found 14 different types of recessive SLCO2A1 mutations. The median age at disease onset and diagnosis was 18.5 (range 1–69) and 40 (range 7–70) years, respectively. Parental consanguinity was present in 16 patients (26%). Although anaemia was present in almost all patients, only two patients experienced gross haematochezia. The median haemoglobin and serum protein levels at diagnosis were 9.7 (range 2.3–13.7) and 5.2 (2.7–8.2) g/dl, respectively. Thirty-three patients (54%) had undergone intestinal surgery. They showed relatively low inflammatory markers in blood tests (median CRP, 2.9 mg/l). The most frequently involved gastrointestinal site was ileum (93%), but the terminal ileum was rarely involved (Figure). Mild digital clubbing or periostosis was found in 16 patients (26%), with six male patients fulfilling the major diagnostic criteria of PHO. The major manifestations of PHO were more frequently found in males than in females (digital clubbing 57% vs. 10%; periostosis 52% vs. 11%; pachydermia 62% vs. 0%).

Conclusion

Although CEAS frequently causes intestinal strictures like CD, its clinical features seem to be distinct from those of CD. Also, a gender difference in clinical symptoms needs to be considered, because concurrent PHO can be frequently seen especially in male patients with CEAS.