Concentration of fecal calprotectin in 11,255 children aged 0–18 years

Abstract

Objectives: Fecal calprotectin is a valued surrogate marker for intestinal inflammation. It has been argued that calprotectin levels are higher in early age than in later life hampering the use of calprotectin in young children. Subjects and methods: To study age-related variation, we used data from our laboratory information system on consecutive, unselected fecal calprotectin measurements from 2014 to 2017 in all children aged 0 to 18 years. From each individual, the first measurement was included and repeated measurements were excluded. Fecal calprotectin was quantitated in the major clinical laboratory in southern Finland, HUSLAB with an ELISA kit from Calpro AS (Calpro/Calprolab, Oslo, Norway). Currently, the assay is performed on two automatic pipetting analysers (Dynex DS2, Chantilly, USA) according to the instructions of the manufacturer. Results: There were altogether 11,255 fecal calprotectin results from as many children. The median level of fecal calprotectin was 51 mg/kg in infants < 1 year of age (95th percentile 648 mg/kg; n = 239). This was 3–4-fold higher when compared to yearly age groups from 1 to 10 years (total number of children included 5,691). Across yearly age groups from 11 to 18, the median values varied from 11 to 19 mg/kg (total number of included children 5,325). The proportion of samples above the routine cut-off for an elevated concentration >100 mg/kg increased with increasing age. Conclusions: Fecal calprotectin values in children beyond the first year of life are in general low and comparable in children and adolescents.