Old and new serological tests for celiac disease screening.

Evaluation of: Lewis NR, Scott BB. Meta-analysis: deamidated gliadin peptide (DGP) antibody and tissue transglutaminase (tTG) antibody compared as screening test for celiac disease. Aliment. Pharmacol. Ther. 31(1), 73-81 (2010). In celiac disease (CD), deamidation of gliadin peptides, induced by tissue transglutaminase (tTG), generates novel antigenic epitopes evoking a specific immune response. Serological tests based on the detection of antibodies to deamidated gliadin peptides (DGP) have been developed with very promising results in terms of sensitivity and specificity for CD screening. In the present study, a meta-analysis of studies published from 1998 to 2008 was designed to compare the performance of DGP antibodies with that of tTG antibodies, the validated and routinely employed test for CD screening. The authors have limited their analysis to IgA class antibodies underlining that most of the considered studies had methodological imperfections, especially ascertainment bias. The results of this meta-analysis indicated that the pooled sensitivities for DGP and tTG antibodies were 87.8% (95% CI: 85.6-89.9) and 93% (95% CI: 91.2-94.5), respectively, and the pooled specificities were 94.1% (95%CI: 92.5-95.5) and 96.5% (95% CI: 95.2-97.5), respectively. In summary, although both tests represent a very good tool for identifying celiac patients, tTG antibodies display a higher predictive value than DGP antibodies, and must still be considered the best serological test for CD screening.