Faecal calprotectin in children with clinically quiescent inflammatory bowel disease

Objective. The use of faecal calprotectin as a surrogate marker for intestinal inflammation is emerging. However, the data on faecal calprotectin during maintenance therapy in children with inflammatory bowel disease, IBD, are sparse. Our aim was to study faecal calprotectin levels in paediatric IBD during clinically quiescent disease and to investigate if high levels were associated with a flare-up of the disease. Subjects and methods. Faecal calprotectin level was measured in 72 children with paediatric IBD in clinical remission (median age 13 years). Of these, 37 children had been in clinical remission for more than a year, 20 for 6-12 months and 15 for 3 to <6 months. The clinical outcome of the patients was followed up to the first relapse or up to 12 months. Results. When in clinical remission, 35% (25/72) of the children had normal faecal calprotectin (<100 mg/g) and 13% (9/72) a very high level (>1000 mg/g) while not reporting symptoms. A clinical relapse occurred in 35% (25/72) during the subsequent 12 months. When in clinical remission, the predictive value of faecal calprotectin for an overt relapse was low ranging from 0.396 to 0.429 for faecal calprotectin values >100 mg/g or >1000 mg/g, respectively. The negative predictive value was 0.75 for values <100 mg/g. Conclusions. In paediatric IBD, subjective symptoms and clinical assessment associate poorly with the levels of faecal calprotectin. During maintenance medication in colonic disease, the probability of staying in clinical remission for a subsequent year is high if faecal calprotectin value is low.