Variability of anti-human transglutaminase testing in celiac disease across Mediterranean countries.
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.
['Smarrazzo|Andrea|A|', 'Magazzù|Giuseppe|G|', 'Ben-Hariz|Mongi|M|', 'Legarda Tamara|Maria|M|', 'Velmishi|Virtut|V|', 'Roma|Elefhteria|E|', 'Kansu|Aydan|A|', 'Mičetić-Turk|Dušanka|D|', 'Bravi|Enzo|E|', 'Stellato|Pio|P|', 'Arcidiaco|Carmela|C|', 'Greco|Luigi|L|']
D002446:Celiac Disease D000068598:Data Accuracy D004797:Enzyme-Linked Immunosorbent Assay D006801:Humans D007070:Immunoglobulin A D019083:Mediterranean Region D011897:Random Allocation D012680:Sensitivity and Specificity D011503:Transglutaminases
Transglutaminase Precision Accuracy Coeliac disease Gluten Non-invasive testing