Introduction Biomarker analysis is commonly used for the diagnosis of those presenting with colorectal symptoms and monitoring of inflammatory bowel disease (IBD), but the acceptability of stool sampling is poor. It is proposed that material rich in the colonic mucocellular layer is deposited on the anal surface post-defaecation and can be sampled for biomarker analysis. Our aim was to develop a novel, non-invasive method of material collection post-defaecation and assess patient acceptability.
Methods Patients with IBD (active cases and those in remission), irritable bowel syndrome (IBS) and a group of healthy volunteers were recruited. Participants were instructed to collect material from the surface of the anus immediately post-defaecation using a specially designed swab covered with flocked nylon (designed by DiagNodus Ltd). The collection process and preparation of samples was performed by patients at home using a specially designed kit. Samples were mailed back, ready for cytological and immunochemical analysis. Patients were provided with kits and asked to collect and return samples at predefined time-points. Patients completed a simple questionnaire to evaluate: (a) procedure convenience/acceptability, (b) ease of sample collection, (c) adequacy of time required for sampling and (d) overall impression each using a 5-point rating scale (1=poor to 5=good).
Results 112 patients were recruited comprising of 60 patients with active IBD, 14 patients with IBD in remission, 31 patients with IBS and 7 healthy volunteers. Collected samples were returned by 97 (86.6%) study participants (88.3% of patients with active IBD, 78.6% of patients with IBD in remission, 87.1% of patients with IBS and 100% of healthy volunteers). Completed questionnaires were returned by 92 trial participants (94.8% of those providing samples). The mean and standard deviation (SD) of participant responses is provided in the table below.
Sampling was not associated with discomfort or harm. The material obtained proved suitable for both cytological assessment and protein biomarker estimation.
Conclusion Material from the colonic mucocellular layer deposited in the anal area following defaecation is readily collectable using our specially designed kit and can provide material for both cytological assessment and biomarker quantification. This simple, reliable process is well tolerated and convenient as patients can provide samples from the comfort of their own home. This new technique warrants further study in different patient groups.
Disclosure of Interest V. Chhaya: None Declared, A. Poullis: None Declared, T. Bandaletova Shareholder of: DiagNodus Ltd, Conflict with: Founder of DiagNodus Ltd, A. Loktionov Shareholder of: DiagNodus Ltd, Conflict with: Founder of DiagNodus Ltd.