Histological healing after infliximab induction therapy in children with ulcerative colitis

To verify the impact of induction therapy with infliximab (IFX) on mucosal healing in children with ulcerative colitis (UC).

The study included all UC pediatric patients treated with IFX at our center over the last 10 years. The data were collected from patients' medical charts and analyzed retrospectively. A total of 16 patients with UC underwent colonoscopy with sample collection before and after three IFX injections. Pediatric Ulcerative Colitis Activity Index (PUCAI) was used to assess the clinical condition; endoscopic features were classified according to the Baron scale; and histological changes were evaluated according to the protocol of The British Society of Gastroenterology and Geboes Index. Clinical response was defined as a ≥ 20-point reduction in PUCAI index, and clinical remission as PUCAI index < 10 points. Endoscopic mucosal remission was defined as completely normal (score 0) on the Baron scale. Histological remission was defined as grade 0 in the Geboes Index. To assess correlation between variables, Spearman's rank correlation coefficient was used.

Clinical remission (PUCAI < 10) at week 8 was achieved in 68.75% of investigated subjects. Endoscopic mucosal remission at week 8 (Baron 0) was observed in 12.5% of patients. Histological remission (Geboes 0) after induction therapy with IFX was noticed in 18.75% cases. A general histological improvement, expressed by normal surface and crypt architecture, number of crypts, and lamina propria cellularity, was observed in six (37.5%) patients; there was no improvement in nine (56.25%) individuals, and worsening was observed in one (3.75%) case. Changes were not related to UC location. A reduction of inflammatory process was observed in 10 (62.5%) patients; there were no changes in four (25%) individuals, and the inflammation became more severe in two (12.5 %) cases. Simultaneous clinical, endoscopic and histological improvement of parameters assessing disease activity at week 8 was noticed in six (37.5%) patients. 55.5% of investigated patients with normal mucosa seen on endoscopy showed no inflammation on histology. A Baron score of 2 and 3 showed a good correlation with histology results (78.2% of patients with a Geboes Index ≥ 3).

IFX has a positive histological effect in more than one-third of UC patients. IFX reduces intestinal inflammation and improves clinical condition.