UNASSIGNED: Objective Faecal (f-) calprotectin is a biomarker of intestinal @entity32 . Previous studies have described intra-individual day-to-day variability of this biomarker in @entity1 with @entity29 ( @entity29 ) and morning samples have been suggested for standardisation purposes. With this project, we investigated if day-to-day variability differed from diurnal variability. Additionally, we evaluated a new extraction method for f-calprotectin analysis. Methods Fifty @entity1 provided three faeces samples from morning - evening - morning on two consecutive days. Nineteen @entity1 provided two faeces samples from the same bowel movement, one conventional spot sample, and one sample with a device for @entity1 -administered sampling and extraction. Results The two morning samples differentiated between @entity32 and @entity33 with same level of agreement as the two samples from the same day (kappa 0.76), using an f-calprotectin cut-off level of 259    g/g. Although large intra-individual variation in f-calprotectin values, there were no significant day-to-day (p   =   0.096) or diurnal variation (p   =   0.78). Used by laboratory technicians, the new extraction device correlated significantly with the conventional extraction method (p   <   0.001), Spearman's rank correlation coefficient 0.95. Of the 19 @entity1 testing @entity1 administered extraction, two @entity1 provided samples leading to considerably higher f-calprotectin levels than conventional sampling procedure. Conclusions The reliability of f-calprotectin morning samples is equal to the reliability of samples from different bowel movements on the same day. The new extraction method is reliable when used by laboratory technicians, but larger studies are recommended to evaluate @entity1 administered extraction.

Clinical importance of faecal calprotectin variability in XXXX : intra-individual variability and standardisation of sampling procedure.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation', 'mucosal inflammation'] @entity33 :: ('MESH:D052016', 'Disease') :: ['mucosal healing'] @entity29 :: ('MESH:D015212', 'Disease') :: ['inflammatory bowel disease', 'IBD']
@entity29 :: (MESH:D015212,Disease) :: ['inflammatory bowel disease']
