Background: The OriCol™ sampling device retrieves mucocellular material from the rectum, providing a unique sample for the study of gastrointestinal disease. The sample can be quickly taken by a trained health care professional and requires no bowel (or other) preparation. OriCol™ has been used in >2500 patients and is well accepted. Samples collected with the OriCol™ device can be used in a range of downstream analyses including investigation of DNA (mutation detection and methylation analysis), protein and antibodies as well as the microbiome.
Faecal calprotectin is routinely used as a marker of inflammation in the initial diagnosis and subsequent management of patients with inflammatory bowel disease (IBD) and its discrimination from irritable bowel syndrome (IBS) which presents with similar symptoms. Here we present data from an ongoing clinical study investigating the potential and suitability of the OriCol™ sample for analysis of calprotectin. The study aims to assess the relationship between calprotectin levels in stool and rectal mucus and thereby establish a threshold in rectal mucus samples that corresponds to the threshold in faeces for determination of inflammatory versus non-inflammatory bowel disease.
Methods: Patients referred with symptoms indicative of new onset IBD or patients with confirmed IBD attending specialist clinics were recruited. OriCol™ and matched stool samples were collected and processed following standard operating procedures. Calprotectin levels were measured using commercially available assays, with 2 protocols being used for processing of OriCol™ samples.
Results: Calprotectin is readily measurable in the OriCol™ samples. Interim analysis in a cohort of 35 patients looking at data from 2 assays showed good correlation between the OriCol™ results from the different kits (correlation coefficient 0.978 and 0.971 compared with 0.883 for parallel stool samples). There was good linearity and recovery of calprotectin measured in the OriCol™ samples in both cases and a clear relationship was seen between calprotectin levels in OriCol™ and stool samples.
Conclusions: The initial results indicate that samples collected with the OriCol™ device can be used to measure calprotectin. Correlation with patient diagnosis and calculation of appropriate thresholds for rectal mucus will be carried out using the full data set with measurements from 4 commercially available assays.