Inter- and Intra-assay variation in the diagnostic performance of anti-tissue transglutaminase antibody assays in two populations

Tissue-transglutaminse-2 (TG2) based immunoassays are the cornerstone of diagnosis in celiac disease (CeD) with a reported pooled sensitivity as high as 98%1. However, a few small, single-center studies have questioned their sensitivity in clinical practice2–5. Moreover, commercial kits use variable TG2 antigens6 with cut-offs determined using small, poorly-defined populations. Variation in diagnostic performance of anti-TG2 assays in different racial and geographic populations has not yet been studied. We compared the interassay and intra-assay variation in diagnostic performance of four IgA-anti-TG2 assays in Canadian and Indian populations.