Anti-tissue transglutaminase antibodies in patients with abnormal liver tests: is it always coeliac disease?
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.
Lo Iacono
Oreste
O
University of Palermo, Gastroenterology and Hepatology Unit, Palermo, Italy.
Petta
Salvatore
S
Venezia
Giovanna
G
Di Marco
Vito
V
Tarantino
Giuseppe
G
Barbaria
Francesco
F
Mineo
Claudia
C
De Lisi
Stefania
S
Almasio
Piero Luigi
PL
Craxì
Antonio
A
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*
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