Are the ESPGHAN criteria valid with the chemioluminiscence method? Analysis of potential diagnostic errors.

Objectives: To determine how many patients may have received a mistaken diagnosis of coeliac disease using the ESPGHAN 2012 and 2020 criteria without performance of biopsy when using chemiluminescence, and to evaluate possible causes of interference affecting anti-tissue transglutaminase antibody results obtained with this technique.

Methods: Retrospective and descriptive study of biopsies of patients with elevated tissue transglutaminase antibodies (tTGA) measured by chemiluminescence in a tertiary care hospital.

Results: The sample included 135 patients with a mean age of 7.7 years. The diagnosis of coeliac disease was confirmed in 67 (49.6%) and ruled out in the remaining 68 (50.4%). Subsequently, among those with a non-diagnostic biopsy, we found that 13 (19.1%) would have met the ESPGHAN 2012 criteria and 17 (25%) the ESPGHAN 2020 criteria. The tTG antibody levels were greater than 10 times the upper limit of normal (ULN) in 27.9%. In patients who tested positive for endomysial antibodies (EMA), the cut-off point for tTGA measured by chemiluminescence that achieved the best combined sensitivity and specificity (Youden index) was 849U/mL (42.5×ULN). On the other hand, if EMA levels were not taken into account, the cut-off point was 301U/mL (15×ULN). In addition, 16 patients (23.5%) received a diagnosis of chronic gastritis secondary to Helicobacter pylori (HP) infection, of who 50% fulfilled the ESPGHAN 2012 and 2020 criteria for diagnosis without biopsy.

Conclusions: Transglutaminase antibody levels measured by chemiluminescence offer a high sensitivity, but there can be artifacts due to situations such as infection by HP. Therefore, the ESPGHAN guidelines must be revised for application in this particular case.