title: Celiac disease in non-clinical populations of Japan.
abstract: BACKGROUND
  Celiac disease is a chronic autoimmune enteropathy caused by gluten ingestion. While its prevalence in Western countries is reported to be as high as 1%, the prevalence has not been evaluated in a large-scale study of a Japanese population. The aim of our study was to clarify the possible presence of celiac disease in a Japanese non-clinical population as well as in patients showing symptoms suggestive of the disease.
  
  
  METHODS
  Serum samples were collected from 2008 non-clinical adults and 47 patients with chronic unexplained abdominal symptoms between April 2014 and June 2016. The anti-tissue transglutaminase (TTG) immunoglobulin A antibody titer was determined as a screening test for celiac disease in all subjects, and individuals with a value of >2 U/mL subsequently underwent testing for the presence of serum endomysial IgA antibody (EMA) as confirmation. Those testing positive for EMA or with a high concentration (>10 U/mL) of TTG were further investigated by histopathological examinations of duodenal mucosal biopsy specimens and HLA typing tests.
  
  
  RESULTS
  Of the 2008 non-clinical adults from whom serum samples were collected, 161 tested positive for TTG, and all tested negative for EMA. Four subjects who had a high TTG titer were invited to undergo confirmatory testing, and the histopathological results confirmed the presence of celiac disease in only a single case (0.05%). Of the 47 symptomatic patients, one (2.1%) was found to have a high TTG titer and was diagnosed with celiac disease based on duodenal histopathological findings.
  
  
  CONCLUSIONS
  The presence of celiac disease in a non-clinical Japanese population was low at 0.05% and was rarely found in patients with unexplained chronic abdominal symptoms.
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Fukunaga
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan. ishimura@med.shimane-u.ac.jp.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Ishimura
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Fukuyama
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.affiliation: Department of Pathology, Shimane University School of Medicine, Izumo, Japan.
authors.forename: Nahoko
authors.initials: N
authors.lastname: Ishikawa
authors.affiliation: Department of Pathology, Shimane University School of Medicine, Izumo, Japan.
authors.forename: Asuka
authors.initials: A
authors.lastname: Araki
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Oka
authors.affiliation: Health Center, Shimane Environment and Health Public Corporation, Matsue, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Mishiro
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Department of Pathology, Shimane University School of Medicine, Izumo, Japan.
authors.forename: Riruke
authors.initials: R
authors.lastname: Maruyama
authors.affiliation: Health Center, Shimane Environment and Health Public Corporation, Matsue, Japan.
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Adachi
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kinoshita
mesh_terms: D015746:Abdominal Pain / Q000453:epidemiology / Q000209:etiology; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D002446:Celiac Disease / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology; D015897:Comorbidity; D003967:Diarrhea / Q000453:epidemiology / Q000209:etiology; D004384:Duodenoscopy; D004386:Duodenum / Q000473:pathology; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007413:Intestinal Mucosa / Q000473:pathology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011503:Transglutaminases / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D011503:Transglutaminases
keywords: Anti-tissue transglutaminase IgA; Antibody; Celiac disease; HLA