Fecal calprotectin as a biomarker of intestinal inflammation in ICU patients with diarrhea – testing the pipette method against the collection pin and weighing methods

Abstract

Fecal calprotectin is an established biomarker in inflammatory bowel disease, but its role in assessment of intestinal inflammation in ICU patients is yet to be explored. ICU patients tend to acquire diarrhea, which complicates the extraction of fecal calprotectin using a collection pin for stool sampling. Pipetting is an alternative sampling method. The aim of the study was to compare the collection pin method with the pipette method for measurement of fecal calprotectin in ICU patients with diarrhea. Stool samples were collected from fecal bags used in the patients and then analyzed for calprotectin using an extraction device and a piston pipette, respectively. In addition, a validation test for the pipette method of extraction was conducted on liquid stool samples. Eleven stool samples were collected from five randomly selected ICU patients. Calprotectin was detectable in all fecal samples. On average the collection pin measured 45% lower than the pipette method with a 95% confidence interval (30 − 59%). The coefficient of variation when using the pipette method was 13% in low calprotectin concentrations and 39% in high concentrations. In conclusion, the pipette method seems to be appropriate for measuring calprotectin in liquid feces, due to practicalities and a greater precision.

Keywords:

• Intensive care unit (ICU) patients
• intestinal inflammation
• fecal calprotectin
• collection pin method
• pipette method

Acknowledgements

We appreciate to the assistance to the study by the staff in the intensive care unit at the North Denmark Regional Hospital and to the co-students, Mads H. Christensen and Thomas V. Christensen, who participated in the initial work.

Author contributions

All authors participated in this study including data interpretation and manuscript preparation. All authors took full responsivities for the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors. The study did not receive any funding.