title: Anti-tissue transglutaminase antibodies in patients with abnormal liver tests: is it always coeliac disease?
abstract: BACKGROUND
  Coeliac disease (CD) is found in 5-10% of patients with chronically abnormal liver tests and no obvious cause of liver disease. In this population the efficacy of screening for CD by anti-tissue transglutaminase (anti-tTG) may be impaired by the high rate of positive anti-tTG found in chronic liver disease.
  
  
  OBJECTIVE
  To evaluate the prevalence of coeliac disease and the role of anti-tTG in patients with non-viral, non-autoimmune chronic and no obvious cause of liver damage.
  
  
  METHODS
  Out of 2,512 consecutive patients with abnormal liver tests, 168 (118 men, 50 women; mean age 40.7 +/- 12.6 years) were defined, on the basis of clinical data and liver biopsy, as NAFLD or cryptogenic chronic hepatitis. All were tested by recombinant IgA and IgG anti-tissue transglutaminase. Patients with a positive serology underwent endoscopy with duodenal biopsies.
  
  
  RESULTS
  NAFLD was diagnosed in 121 patients, in 6 associated with cirrhosis, while 47 patients were considered as cryptogenic hepatitis in the absence of steatosis. Anti-tTG were positive in 20/168 patients (3 IgA alone; 11 IgG alone; 6 both IgA and IgG). Coeliac disease was found at endoscopy and confirmed by histopathology only in the 6 patients (3.6%) with both IgA and IgG anti-tTG positivity. Four of the patients with CD had NAFLD (3.3%), in 2 of them associated with cirrhosis; while 2 of those with cryptogenic hepatitis (4.2%) had CD.
  
  
  CONCLUSIONS
  The prevalence of CD in patients with chronically abnormal liver tests of unexplained etiology is 4%, with no relation with the degree of liver steatosis. Screening should be done by testing for IgA and IgG antibodies and then evaluating by endoscopy and biopsy only patients positive for both.
authors.affiliation: University of Palermo, Gastroenterology and Hepatology Unit, Palermo, Italy.
authors.forename: Oreste
authors.initials: O
authors.lastname: Lo Iacono
authors.forename: Salvatore
authors.initials: S
authors.lastname: Petta
authors.forename: Giovanna
authors.initials: G
authors.lastname: Venezia
authors.forename: Vito
authors.initials: V
authors.lastname: Di Marco
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tarantino
authors.forename: Francesco
authors.initials: F
authors.lastname: Barbaria
authors.forename: Claudia
authors.initials: C
authors.lastname: Mineo
authors.forename: Stefania
authors.initials: S
authors.lastname: De Lisi
authors.forename: Piero Luigi
authors.initials: PL
authors.lastname: Almasio
authors.forename: Antonio
authors.initials: A
authors.lastname: Craxì
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000032:analysis; D001219:Aspartate Aminotransferases / Q000032:analysis; D001323:Autoantibodies / Q000032:analysis*; D001706:Biopsy; D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology; D004384:Duodenoscopy; D004386:Duodenum / Q000276:immunology / Q000473:pathology; D005234:Fatty Liver / Q000175:diagnosis / Q000276:immunology; D005260:Female; D019204:GTP-Binding Proteins / Q000276:immunology*; D006521:Hepatitis, Chronic / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D008099:Liver / Q000276:immunology / Q000473:pathology; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000276:immunology; D008107:Liver Diseases / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D019204:GTP-Binding Proteins