TY - JOUR TI - Variability of anti-human transglutaminase testing in celiac disease across Mediterranean countries AU - Smarrazzo, A. AU - Stellato, P. AU - Arcidiaco, C. AU - Greco, L. AU - Magazzù, G. AU - Ben-Hariz, M. AU - Tamara, M.L. AU - Velmishi, V. AU - Roma, E. AU - Kansu, A. AU - Mičetić-Turk, D. AU - Bravi, E. JO - World Journal of Gastroenterology PY - 2017 VL - 23 TODO - 24 SP - 4437-4443 PB - Baishideng Publishing Group Co SN - 1007-9327 TODO - 10.3748/wjg.v23.i24.4437 TODO - protein glutamine gamma glutamyltransferase antibody; immunoglobulin A; protein glutamine gamma glutamyltransferase, Albania; antibody titer; Article; celiac disease; controlled study; diagnostic accuracy; diagnostic test accuracy study; diagnostic value; Greece; human; immunoassay; Italy; multicenter study; randomized controlled trial; Slovenia; Spain; Tunisia; Turkey (republic); blood; celiac disease; clinical trial; enzyme linked immunosorbent assay; immunology; measurement accuracy; randomization; sensitivity and specificity; Southern Europe; validation study, Celiac Disease; Data Accuracy; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin A; Mediterranean Region; Random Allocation; Sensitivity and Specificity; Transglutaminases TODO - AIM To verify the precision and accuracy of transglutaminase antibodies (TGA) assays across Mediterranean countries. METHODS This study involved 8 referral centres for celiac disease (CD) in 7 Mediterranean countries. A central laboratory prepared 8 kits of 7 blinded and randomized serum samples, with a titrated amount of Human TGA IgA. Each sample was analysed three times on three different days, with each centre running a total of 21 tests. The results were included in a blindly coded report form, which was sent to the coordinator centre. The coordinator estimated the mean coefficient of Variation (CoVar = σ/μ), the mean accuracy (Accur = Vobserved -Vreal) and the mean percent variation (Var% = [(Vobserved -Vreal)/Vreal] × 100). RESULTS The analysis showed that 79.17% of the mean variation fell between -25% and +25% of the expected value, with the accuracy and precision progressively increasing with higher titres of TGA. From values 1.25 times greater than the normal cut-off, the measurements were highly reliable. CONCLUSION TGA estimation is a crucial step for the diagnosis of CD; given its accuracy and precision, clinicians could be confident in establishing a diagnosis. © The Author(s) 2017. ER -