In certain circumstances, tissue-transglutaminase antibodies (TGA) can be used to detect celiac disease (CD) without a biopsy. For a study, researchers sought to examine the real-world performance of a CD serology automated analyzer (Bioplex2200) and the relationship between TGA levels and intestinal biopsies in children. Between November 1, 2018, and April 1, 2020, a retrospective assessment of patients with TGA serology tests and duodenal biopsies was conducted in two pediatric gastroenterological clinics. Patient demographics, medical history, TGA levels, and biopsy results were among the information obtained.

Overall, 538 children were tested, 256 of whom had positive TGA (68.4% were girls, median age 6.4) and 282 of whom had negative TGA (53.9% girls, median age 13.4). In 219 TGA-positive patients, intestinal biopsies revealed CD (85.5%). Overall, 14.5% of the cohort had positive serology with normal histology, with 52%, 21.6%, 21.1%, and 4.2% in TGA ranges of 1-3 times upper limit of normal (ULN), 3-5 times ULN, 5 to 10 times ULN, and above 10 times ULN, respectively, P <0.001. The area under the receiver-operating characteristic curve (AUC) was 0.963 (95% CI 0.947–0.980). About 216 (84.4%) of patients with positive TGA also showed positive anti-endomysial antibodies. The overall diagnostic performance in this subgroup was poor, with an AUC of 0.737 (95% CI 0.834–0.839).

In practice, the Multiplex TGA test demonstrated a very good diagnostic accuracy. Adding EMA to patients with positive TGA did not enhance the test’s diagnostic effectiveness. False-positive rates varied by TGA range and were lowest when TGA exceeded 10 times the ULN.