Human tissue transglutaminase enzyme linked immunosorbent assay outperforms both the guinea pig based tissue transglutaminase assay and anti-endomysium antibodies when screening for coeliac disease.

UNLABELLED: Anti-endomysium antibodies (EMA) and antigliadin antibodies (AGA) are widely used when screening for coeliac disease (CD), although their specificity and sensitivity are suboptimal. The guinea pig tissue transglutaminase (tTG) assay also did not prove to be superior. A newly developed enzyme linked immunosorbent assay (Celikey), based on human tTG, might however have a better performance. We therefore investigated the sensitivity and specificity of this human IgA tTG assay in 101 patients with aspecific gastrointestinal complaints and compared this to guinea pig IgA tTG, AGA and EMA. A total of 52 patients with CD were investigated and 49 patients without CD. All had a small bowel biopsy. Our results showed that human IgA tTG had a sensitivity of 96% and a specificity of 100%. Guinea pig IgA-tTG had a sensitivity of 96% and a specificity of 92%. EMA had a sensitivity of 92% and a specificity of 90%. Both IgA AGA and IgG AGA had a sensitivity of 83% whilst having a specificity of 86% and 80% respectively.
CONCLUSION: both the human IgA tissue transglutaminase enzyme linked immunosorbent assay and the guinea pig IgA tissue transglutaminase assay could better identify patients with coeliac disease than IgA anti-endomysium antibodies. Although in a larger series of control patients the specificity for the human IgA tissue transglutaminase enzyme linked immunosorbent assay might fall below 100%, in our opinion this is currently the serological method of choice in identifying patients with coeliac disease in the absence of IgA deficiency.