Background: Conflicting results were obtained in the assay of anti-transglutaminase (anti-tTG) autoantibodies in patients with chronic liver disease. In order to establish whether this was attributable to methodological differences, anti-tTG antibodies were assayed in a large number of patients suffering from liver cirrhosis (LC).
Methods: 54 patients with LC and 29 patients suffering from celiac disease (CD), used as controls, were tested for IgA and IgG anti-tTG with 11 different commercial methods.
Results: In the patients with LC, positivity ranged from 0% to 33.3% for IgA anti-tTG and from 0% to 11.1% for anti-tTG of the IgG class. The largest number of false positives was found with methods that used tTG in association with gliadin peptides as antigen substrate. A significant association was found between IgA anti-tTG antibodies and serum immunoglobulin concentration.
Conclusions: The results of the various methods of assaying anti-tTG antibodies in patients with LC are highly variable, and the positives found are generally false positives, partly due to the high immunoglobulin concentration.