There remains a dearth of Asian epidemiological literature for paediatric inflammatory bowel disease (PIBD).

To describe the presenting features of PIBD from 7 Asia-Pacific pediatric gastroenterology centers via a central standardised electronic data platform.

Clinical, endoscopic and radiologic data at diagnosis from the registry were extracted between 1st January 1995 to 31st December 2019. Disease phenotypic characteristics were classified as per the Paris classification system.

There was a distinct rise in new PIBD cases: Nearly half (48.6%) of the cohort was diagnosed in the most recent 5 years (2015-2019). The ratio of Crohn's disease (CD):Ulcerative colitis (UC):IBD-Unclassified was 55.9%:38.3%:5.8%. The mean age was 9.07 years with a high proportion of very early onset IBD (VEO-IBD) (29.3%) and EO-IBD (52.7%). An over-representation of the Indian/South Asian ethnic group was observed which accounted for 37.0% of the overall Singapore/Malaysia subcohort (6.8%-9.0% Indians in census). Indian/South Asian CD patients were also most likely to present with symptomatic perianal disease (P = 0.003). CD patients presented with significantly more constitutional symptoms (fever, anorexia, malaise/fatigue and muscle-wasting) than UC and higher inflammatory indices (higher C-reactive protein and lower albumin levels).

We observed a high incidence of VEO-IBD and an over-representation of the Indian ethnicity. South Asian CD patients were more likely to have symptomatic perianal disease.

The diagnosis of IBD and evaluation of treatment require endoscopy, which is difficult in children. This study evaluated the use of TFF3 as a biomarker.

Permeability of the intestinal mucosa and serum TFF3 were assayed and colon tissue was harvested 7 days after inducing IBD in mice with TNBSA. TFF3 was monitored in 51 pediatric IBD patients stratified by active disease or remission and in 20 healthy children. Mucosal healing was assessed by the Simple Endoscopic Score for Crohn Disease and Baron scores in CD and UC patients.

Histological evaluation revealed transmural inflammation of the colon in IBD model mice. Permeability of the intestinal mucosa and serum TFF3 were both higher in TNBSA-treated than in control mice (P < 0.05). TFF3 was higher in children with active IBD than in those in remission and in healthy children (P < 0.05). TFF3 was positively correlated with the SES-CD score (P < 0.05) but not with either the pediatric CDAI score or the serum CRP. The sensitivity of serum TFF3 for monitoring CD activity was 100% and the specificity was 76.2%.

TFF3 level increased with CD activity, which is of significance for diagnosis and for evaluation of mucosal healing. TFF3 could also be a marker in pediatric UC, as TFF3 positively correlated with UCAI.

The diagnosis and evaluation of IBD is difficult; endoscopy provides objective assessment; TFF3 can be a useful marker instead of endoscopy. TFF3 was increased in active CD of children; TFF3 can be used as a clinical marker of pediatric CD; TFF3 can diagnose and evaluate mucosal healing of CD. Pediatrician should pay attention to clinical marker; TFF3 level may be a key evaluation of mucosal healing of CD; the value of diagnosis of TFF3 in CD is important.