Human recombinant anti-transglutaminase antibody testing is useful in the diagnosis of silent coeliac disease in a selected group of at-risk patients.

BACKGROUND: Functional dyspepsia, unexplained chronic hypertransaminasaemia (CHT) and hepatitis C virus (HCV) are common gastrointestinal situations that have been related to coeliac disease. Antibodies to tissue transglutaminase (tTG) have been claimed recently to be highly effective as a screening method for coeliac disease. AIM: To assess the prevalence of coeliac disease by means of detection of antibodies against human tTG in the above-mentioned groups of patients. PATIENTS AND METHODS: A control group consisted of 165 normal blood donors. Patient groups comprised 90 CHT patients, 102 HCV patients and 92 functional dyspepsia patients. All patients were tested for anti-tTG (immunoglobulin A, IgA) antibodies. Anti-endomysium (IgA) antibodies (AEA) and antigliadin (IgA) antibodies (AGA) and antigliadin (immunoglobulin G, IgG) antibodies (AGG) were also tested. When anti-tTG or AEA was positive, a duodenal biopsy was recommended.
RESULTS: One of 165 blood donors, three of 92 functional dyspepsia patients, four of 90 CHT patients and none of 102 HCV patients were positive for anti-tTG antibodies. In the anti-tTG-positive group, all but one were AEA-positive. There were no AEA- or AGA IgA-positives that revealed a negative anti-tTG test. Duodenal biopsy confirmed a diagnosis of coeliac disease in all the cases. Statistically significant differences were found between the controls and the functional dyspepsia group and between the controls and the CHT group, but not between the controls and the HCV group.
CONCLUSIONS: Both CHT and functional dyspepsia may represent a true oligosymptomatic form of coeliac disease. In such conditions, the detection of anti-tTG antibodies is useful as a screening method. Coeliac disease is not an autoimmune manifestation of HCV, so screening for coeliac disease in HCV patients cannot be recommended.