PT  - JOURNAL ARTICLE
AU  - Sjoukje-Marije Haisma
AU  - Patrick Ferry van Rheenen
AU  - Lucie Wagenmakers
AU  - Anneke Muller Kobold
TI  - Calprotectin instability may lead to undertreatment in children with IBD
AID  - 10.1136/archdischild-2018-316584
DP  - 2019 Jun 11
TA  - Archives of Disease in Childhood
PG  - archdischild-2018-316584
4099  - http://adc.bmj.com/content/early/2019/06/10/archdischild-2018-316584.short
4100  - http://adc.bmj.com/content/early/2019/06/10/archdischild-2018-316584.full
AB  - Background Treatment decisions in children with inflammatory bowel disease (IBD) are increasingly based on longitudinal tracking of faecal calprotectin concentrations, but there is little known about the stability of this protein in stool.Methods We stored aliquots of homogenised stool at room temperature and at 4°C, and measured the calprotectin concentration for 6 consecutive days with three different assays. In addition, we assessed calprotectin stability in assay-specific extraction buffers kept at room temperature.Results After 6 days of storage at room temperature, mean percentage change from baseline calprotectin concentrations in stool and extraction buffer was 35% and 46%, respectively. The stability of calprotectin was significantly better preserved in samples stored at 4°C (p=0.0066 and 0.0011, respectively).Conclusions Calprotectin is not stable at room temperature. Children with IBD and their caretakers may be falsely reassured by low calprotectin values. The best advisable standard for preanalytical calprotectin handling is refrigeration of the stool sample until delivery at the hospital laboratory.