Eosinophilic esophagitis in Japanese patients: A mild and slow-progressing disorder

Abstract

Background and aim: Awareness of eosinophilic esophagitis (EoE) has gradually increased in Japan, therefore the characteristics of this disease in the Japanese patient population need to be elucidated. This study aimed to investigate the features of EoE in the Japanese population.

Methods: During a 2-year period, all gastrointestinal endoscopies were performed with maximum attention being paid to identify EoE through endoscopic findings. Clinical features and findings were analyzed among this population.

Results: Among a total of 8589 patients (general gastrointestinal endoscopy, performed for evaluation of symptoms or disease follow-up: 3669; medical check-up endoscopy, routinely performed in asymptomatic patients: 4920), 17 patients (0.20%) were diagnosed with esophageal eosinophilia (mean age ± standard deviation: 44±11.9 years; 1 female). Only 6 patients with esophageal eosinophilia were diagnosed by general gastrointestinal endoscopy; among them, 3 patients had dysphagia and 3 were asymptomatic. The remaining 11 patients were diagnosed by medical check-up endoscopy. All patients were treated with a proton pump inhibitor (PPI); 5 were diagnosed with EoE and 12 with PPI responsive esophageal eosinophilia. Chronological endoscopy analysis showed that EoE findings could be observed for a mean of 6.1 years prior to diagnosis, and the disease did not significantly progress in severity.

Conclusions: Most Japanese patients with EoE have mild and slowly progressing disease, which can be diagnosed when close attention is paid to the endoscopic findings. Medical check-up endoscopy in Japan could be a great opportunity for the early diagnosis of EoE.

Fig 1. Diagnostic diagram of eosinophilic esophagitis (EoE) in this study.

Among a total of 8589 patients who underwent gastrointestinal endoscopy, 17 (0.20%) were diagnosed with esophageal eosinophilia (EE). Six cases of EE were diagnosed by general gastrointestinal endoscopy. Among them, 3 had dysphagia and 3 were asymptomatic. The remaining 11 cases were diagnosed by medical check-up endoscopy routinely performed in asymptomatic adults. On interview, 2 patients had dysphagia, 5 had slight chest discomfort or heart burn, and 4 were asymptomatic. EoE was diagnosed in 5 patients and proton pump inhibitor–responsive esophageal eosinophilia in 12. All were treated by proton pump inhibitor.

Fig 2. Time series of endoscopic findings using an endoscopy database.

The red solid line indicates the period when the endoscopic findings of eosinophilic esophagitis (EoE) were observed, and the dotted line indicates the period when endoscopic findings of EoE were not identified. Over a mean period of 6.1 years during which endoscopic findings of EoE were observed, only 1 patient developed dysphagia (blue triangle indicates the point of dysphagia) and 7 were asymptomatic (yellow triangle indicates the point of chest discomfort).

Fig 3

(a) Endoscopy showing loss of vascularity and longitudinal furrows (yellow triangles) in the lower esophagus (Eosinophilic Esophagitis Endoscopic Reference Score [EREFS]: 2); esophageal eosinophilia was diagnosed on histology. The patient was asymptomatic. Inset shows the endoscopy finding 4 years prior in the same patient. Loss of vascularity and longitudinal furrows were already visible (EREFS: 2). (b) Esophageal biopsy demonstrates severe eosinophilic infiltration (200 X). Inset magnification, 400 X.