Serum positivity of serum anti-tissue transglutaminase immunoglobulin A antibodies in Japanese children with inflammatory bowel disease.

Background: Serum anti-tissue transglutaminase immunoglobulin A antibody (tTG-IgA) is a screening test for celiac disease (CeD). In recent years, there have several reports of combined inflammatory bowel disease (IBD) and CeD in children. The purposes of this study are to research the positivity of the tTG-IgA antibody in Japanese children, and whether IBD and CeD co-occur.

Methods: We examined tTG-IgA as a screening test for CeD in symptomatic pediatric patients with IBD (cases) and those without IBD (controls, non-IBD). Those with tTG-IgA levels of 10 U/mL or higher were considered positive. All patients had routine biopsy specimens taken from the second part and bulbus of the duodenum, and were evaluated histologically based on the Marsh classification.

Results: Thirty-one patients in the IBD group and 53 patients in the non-IBD group were included. The tTG-IgA was positive in five cases (5.9%) and median titer of positive cases was 12.3 U/mL (10.2-41.7). One patient in the IBD group (3.2%) and four patients in the non-IBD group (7.8%) were positive for tTG-IgA. No cases showed histological features of CeD. There were no statistically significant differences in age, sex, symptoms and laboratory tests between the tTG-IgA positive and negative groups. Patients among the IBD and the non-IBD groups that were tTG-IgA positive demonstrated symptoms after wheat consumption.

Conclusions: We identified a patient who was positive for tTG-IgA antibodies who experienced abdominal symptoms due to wheat ingestion, indicative of subclinical CeD. Further investigation is needed to clarify the co-occurrence of IBD and CeD among Japanese children.