Our study examined histopathological changes in the distribution of IBD from diagnosis through follow-up in children and attempted to determine factors that would influence the progression of inflammatory bowel disease in this population.
The initial disease histopathological distribution in those ulcerative colitis patients with disease progression in our study was similar to those in previous studies, citing pancolitis, left sided colitis and proctitis as the most common distributions [1, 3, 4, 7, 8, 11]. For the ulcerative colitis population, 40.7% of our patients showed disease progression. It appears that there is no relationship to age, duration of symptoms pre-diagnosis, weight, height, serum albumin levels, ESR and disease activity index at diagnosis. Interestingly, some patients with pancolitis in our series, who did not have any evidence of upper gastrointestinal involvement on initial endoscopy, had evidence of histopathological abnormalities on follow-up endoscopy. Upper gastrointestinal involvement in children with UC has been previously reported .
The most common initial disease histopathological involvements of Crohn’s disease in our study were terminal ileum, ileocecal and upper GI involvement. This finding agreed with previous studies which found that 50 – 70% of their pediatric CD patients had TI involvement at presentation [7, 13, 14]. About 75% of the CD patients in our study showed disease progression. It appears that there is a significant relationship between sex (OR = 0.13, 95% CI = 0.02 – 0.79) and disease progression. Based on our analysis, it appears that disease progression is less likely with those patients who are female when compared to those that are male. However, a previous study by Freeman demonstrated that CD tended to be more prominent in females when compared to their male counterparts . Interestingly, in a previous study, it was determined that the switch to a female predominance began at around the age of adolescence . It also appears that there is a significant relationship between ESR at diagnosis and disease progression in Crohn’s disease patients. Disease progression is more likely in those Crohn’s disease patients that have a higher ESR at diagnosis than those with a lower ESR at diagnosis. There are no previous studies to which we can compare these results.
Although we attempted to optimize the results obtained from our retrospective chart review, our study was limited in a few areas. Firstly, our study defined disease progression strictly as histopathological changes in disease distribution from diagnosis to follow up. Although this definition served the purpose of our study, perhaps future research could also look into disease progression in the sense of clinical presentation and symptoms, and whether or not factors affecting the clinical presentation and symptoms can predict IBD progression. Of note is that, large areas of small bowel could not normally be biopsied to explore histopathological involvement of Crohn’s disease.
Secondly, our study excluded those patients that did not have colonoscopy/endoscopy at follow up. Although that was necessary for the purpose of our study, perhaps future studies could look at disease status at follow up in another sense (to increase the number of IBD subjects available for the study). One can argue that patients with less controlled disease will be more likely to be scoped and hence selection bias is more likely to take place. Thirdly, for the purpose of our study, our subjects were divided into 2 main categories: disease progression and no disease progression. Future studies may benefit by further dividing the disease presentation and progression categories into mild, moderate and severe disease. In this sense, there may be a better understanding of which factors may affect certain stages of IBD in children.