Clinical Variables as Predictors of First Relapse in Pediatric Crohn's Disease

Introduction Crohn's disease (CD) is an immune-mediated inflammatory bowel disease (IBD) that can affect any portion of the gastrointestinal tract from the mouth to the anus. The clinical course of CD is characterized by periods of symptomatic relapse and remission. Clinical variables may identify a subset of patients with CD at risk for relapse. Identifying these patients, and early stratification-based treatment would be of utmost clinical importance in optimizing the management and is likely to improve long-term disease outcome. In pediatric-onset IBD there is a paucity of data for predicting clinical behavior and results are conflicting. With this background, we hypothesized that routinely measured clinical variables at the time of diagnosis would predict relapse in patients with CD, and sought to investigate the clinical predictors of relapse present at the time of diagnosis in our patient population. We further compared differences in clinical variables and laboratory values for patients who relapsed early, compared with those who relapsed late. Methods We conducted a retrospective chart review of patients diagnosed with CD by clinical, radiological, endoscopic and histological criteria at St. John Providence Children's Hospital pediatric GI clinic between 01/2006 and 12/2014. Patients were followed until they had their first relapse or for three years from diagnosis, whichever was earlier. Variables studied included demographic factors (age, gender, race, BMI, BMI percentiles and family history of IBD), presenting symptoms (blood in stools, nocturnal stools, fever, and extra-intestinal manifestations), phenotypic characteristics (using Montreal classification), and laboratory data [white blood cell (WBC) count, hemoglobin, hematocrit, platelet count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)]. Results Twenty-nine patients were included in the study. One was lost to follow up, and 28 were included in the analyses. The relapse rate was 50% at three years, and 32% patients relapsed within one year of diagnosis. Low BMI percentile at diagnosis (41.5 ± 28.8 vs. 18.0 ± 20.3; p-value 0.03) was a predictor of relapse. Comparing early relapse to those who relapsed late, there were no statistically significant differences between the two groups. Conclusions Low BMI percentile at presentation was associated with increased risk of relapse, suggesting that routinely measured clinical variables may have role in predicting first relapse in this patient population. There was no significant difference in the variable comparing patients who relapsed early vs. those who relapsed late. Future prospective studies with larger sample sizes need to be done to predict relapse.