Variability of anti-human transglutaminase testing in celiac disease across Mediterranean countries

World J Gastroenterol. 2017 Jun 28;23(24):4437-4443. doi: 10.3748/wjg.v23.i24.4437.


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.

Keywords: Accuracy; Coeliac disease; Gluten; Non-invasive testing; Precision; Transglutaminase.

Publication types

  • Multicenter Study
  • Observational Study
  • Validation Study

MeSH terms

  • Celiac Disease / blood*
  • Celiac Disease / diagnosis
  • Celiac Disease / immunology
  • Data Accuracy*
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunoglobulin A / blood*
  • Mediterranean Region
  • Random Allocation
  • Sensitivity and Specificity
  • Transglutaminases / immunology*


  • Immunoglobulin A
  • Transglutaminases