EmAs with recombinant human anti-tTG ELISAs for CD

discrepancy among methods, probably related to differences in the extraction and preparation of the antigen. One CD patient in our study had negative results with all four assays with IgA anti-tTG concentrations even lower than those of controls in two of the tested ELISAs. This might be tentatively accounted for by the occurrence of autoantibodies directed against an antigen different from tTG, yet leading to EmA positivity (19 ). Moreover, for each package a gray zone within the reference limits renders borderline values difficult to interpret: they should be considered according to the clinical setting. In this study, we tested only samples drawn from EmA-positive CD patients; performances of anti-tTG ELISAs need further evaluation in a prospective cohort of patients referred to a malabsorption clinic, including those with EmA-negative results and a larger number of controls affected by diverse pathologies. This might avoid the need to use borderline values. At present, we are unable to recommend the complete replacement of EmAs with recombinant human anti-tTG ELISAs for CD screening purposes, although the combination of the two methods can be proposed, especially when faced with borderline values that fall in the gray zone.