Anders Lasson1, Per-Ove Stotzer2, Lena Öhman3, Stefan Isaksson4, Maria Sapnara5, Hans Strid2. 1. Department of Internal Medicine, Södra Älvsborgs Hospital, Borås, Sweden anders.lasson@vgregion.se. 2. Department of Internal Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. 3. Department of Internal Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden Department of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Sweden. 4. Department of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Sweden Department of Internal Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. 5. Department of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Sweden.
Abstract
BACKGROUND AND AIMS: Leukocyte-derived proteins in faeces, especially calprotectin, are increasingly used to assess disease activity in ulcerative colitis. The objectives of the present study were to assess the importance of factors related to the stool sampling procedure. METHODS: For 2 days, patients with active ulcerative colitis collected two stool samples at each bowel movement. The time of defecation, consistency and presence of blood were self-recorded in a diary. The variability in the concentrations of calprotectin during the day and between two consecutive days was assessed, as was the stability of calprotectin concentrations in samples stored at room temperature. RESULTS: Altogether, 18 patients collected 287 stool samples. The intraclass correlation coefficient in pairs of samples from 132 bowel movements was 0.79 (95% CI 0.48-0.90). The median individual coefficient of variation in samples collected during the same day was 52% (4-178). There was a correlation between the level of calprotectin and the time between bowel movements (r = 0.5; p = 0.013). After 3 days at room temperature the calprotectin concentrations in stool samples were unchanged, but after 7 days a significant (p < 0.01) decrease was found (mean 28%; 95% CI 0.10-0.47). CONCLUSION: The present data reveal a great variability in the concentrations of calprotectin in stool samples collected during a single day. Since the levels of calprotectin increased with longer time between the bowel movements, it seems most appropriate to analyse stool from the first bowel movement in the morning. Moreover, storage of stool samples at room temperature for more than 3 days is not advisable.
BACKGROUND AND AIMS: Leukocyte-derived proteins in faeces, especially calprotectin, are increasingly used to assess disease activity in ulcerative colitis. The objectives of the present study were to assess the importance of factors related to the stool sampling procedure. METHODS: For 2 days, patients with active ulcerative colitis collected two stool samples at each bowel movement. The time of defecation, consistency and presence of blood were self-recorded in a diary. The variability in the concentrations of calprotectin during the day and between two consecutive days was assessed, as was the stability of calprotectin concentrations in samples stored at room temperature. RESULTS: Altogether, 18 patients collected 287 stool samples. The intraclass correlation coefficient in pairs of samples from 132 bowel movements was 0.79 (95% CI 0.48-0.90). The median individual coefficient of variation in samples collected during the same day was 52% (4-178). There was a correlation between the level of calprotectin and the time between bowel movements (r = 0.5; p = 0.013). After 3 days at room temperature the calprotectin concentrations in stool samples were unchanged, but after 7 days a significant (p < 0.01) decrease was found (mean 28%; 95% CI 0.10-0.47). CONCLUSION: The present data reveal a great variability in the concentrations of calprotectin in stool samples collected during a single day. Since the levels of calprotectin increased with longer time between the bowel movements, it seems most appropriate to analyse stool from the first bowel movement in the morning. Moreover, storage of stool samples at room temperature for more than 3 days is not advisable.
Authors: Christopher Andrew Lamb; Nicholas A Kennedy; Tim Raine; Philip Anthony Hendy; Philip J Smith; Jimmy K Limdi; Bu'Hussain Hayee; Miranda C E Lomer; Gareth C Parkes; Christian Selinger; Kevin J Barrett; R Justin Davies; Cathy Bennett; Stuart Gittens; Malcolm G Dunlop; Omar Faiz; Aileen Fraser; Vikki Garrick; Paul D Johnston; Miles Parkes; Jeremy Sanderson; Helen Terry; Daniel R Gaya; Tariq H Iqbal; Stuart A Taylor; Melissa Smith; Matthew Brookes; Richard Hansen; A Barney Hawthorne Journal: Gut Date: 2019-09-27 Impact factor: 23.059