P483. Faecal calprotectin exhibits diurnal variation in inflammatory bowel disease patients but is not affected by time of day
C. Dobrzanski1, N. Pedersen1, V. Voxen Hansen2, H. Fuglsang2, L.V. Lennert1, P. Munkholm1, 1Herlev University Hospital, Department of Gastroenterology, Copenhagen, Denmark, 2Herlev University Hospital, Gastroenterology Research Laboratory, Copenhagen, Denmark
Faecal calprotectin (FC) is known to exhibit day to day variability . The aim of this study is to investigate the magnitude of FC diurnal variation in inactive (SCCAI ≤2) and active (SCCAI >2) ulcerative colitis (UC) patients, inactive (HBI ≤5) and active (HBI >5) Crohn's Disease (CD) patients and in healthy controls. Furthermore, we study if time of day influences FC levels in inflammatory bowel disease (IBD) patients.
IBD patients were consecutively recruited from the out-patient clinic at Herlev Hospital during 2012. Controls were healthy healthcare workers and friends. All study subjects were asked to deliver a faecal sample from each stool they had during 3 days. Time and date had to be provided for each sample before sending them by post to the gastroenterology research laboratory for FC analysis by ELISA (CALPRO Inc.). The subject's individual FC diurnal variation was defined as the largest difference between the highest (FC high) and the lowest (FC low) FC values on the same day. FC daily variation was defined as the difference in the patient's mean FC values during 01.00–12.59 (FC morning) and mean FC values during 13.00–00.59 (FC afternoon). Statistical analysis was done by non-parametric Wilcoxon signed-rank and Kruskal–Wallis tests.
A total of 514 FC samples were collected from 51 IBD patients (15 inactive UC (UCI), 14 active UC (UCA), 12 inactive CD (CDI), 10 active CD (CDA); total 55% female) and 30 healthy controls (53% female).
FC diurnal variation in healthy controls differed significantly from UCI (p = 0.001), UCA (p < 0.0001), CDI (p = 0.018) and CDA (p < 0.0001). Mean FC in healthy controls differed significantly from UCI (p < 0.0001), UCA (p < 0.0001), CDI (p < 0.0001) and CDA (p < 0.0001). Mean FC in UCA differed significantly from UCI (p < 0.0001), CDI (p < 0.032) and CDA (p = 0.001). There was no statistically significant difference between FC morning and FC afternoon in the patient groups (UCI, p = 0.100; UCA, p = 0.972; CDI, p = 0.401; CDA, p = 0.374) nor in FC daily variation in between patient groups (p = 0.785).
|FC diurnal variation, mg/kg (mean±SD)||229±295||581±573||137±117||289±234||18.2±20.9|
|Mean FC, mg/kg (mean±SD)||237±352||752±611||371±434||232±277||20.4±24.3|
|FC high, mg/kg (mean±SD)||337±388||899±640||463±451||504±428||29.8±33.0|
|FC low, mg/kg (mean±SD)||108±135||318±332||326±399||215±317||11.65±15.7|
|No. of FC tests||83||106||74||92||159|
|Defecations per subject per day (mean±SD)||2.4±0.8||3.3±2.7||2.4±0.8||3.9±2.0||1.8±0.5|
|FC daily variation, mg/kg (mean±SD)||62±118||64±280||31±70||23±56||−|
|FC morning, mg/kg (mean±SD)||167±214||542±462||292±430||209±132||−|
|FC afternoon, mg/kg (mean±SD)||229±308||606±499||323±423||232±168||−|
FC diurnal variation in healthy controls is negligible. In UCI, CDI and CDA patients, FC diurnal variation is acceptable when monitoring disease activity by FC in routine clinical practice. In UC patients with active disease, FC diurnal variation is substantial and clinically considerable. We suspect, however, that irregular amounts of blood, pus and mucus in the stool could affect FC levels in these patients. Time of day does not influence FC levels in IBD patients.
1. Moum B, Jahnsen J, Bernklev T, (2010), Fecal calprotectin variability in Crohn's disease, Inflamm Bowel Dis., 16: 1091–1092.