Validation of a new extraction device for measuring faecal calprotectin in inflammatory bowel disease, and comparison to established extraction methods.

Objective: Faecal (f-) calprotectin is a widely used surrogate marker of intestinal inflammation. F-calprotectin analysis is labour demanding partly due to a time consuming extraction step. The aim of this project was to validate a new extraction method for f-calprotectin. Material and methods: A prospective multicentre study included 135 patients with an established diagnosis of inflammatory bowel disease. The patients submitted a faeces sample, which was extracted with both the conventional method at the participating laboratory and the new extraction device. The extracts were analyzed by an automated ELISA instrument. Results: Method comparison of the traditional method and the new device showed a slope of 1.01 (0.93-1.07) with intercept of 2.2 ( 4.9-0.6). The Spearman rank correlation coefficient was 0.96. Conclusions: The new extraction device is a reliable and time saving alternative to the conventional extraction method.