A new rapid home test for faecal calprotectin in ulcerative colitis

Abstract

BACKGROUND: Enzyme-linked immunosorbent assay (ELISA) is a time-consuming method for the measurement of faecal calprotectin. Two new quantitative rapid tests have been developed. AIM: To compare the new rapid tests with ELISA as 'Gold Standard'. METHODS: Quantitative analysis involved the application of a sample onto the 'Lateral Flow Device'. The colour intensity of a test line was read using a laptop computer linked to a scanner (rapid test scanning). A picture taken with a mobile phone (HT photo) of the same 'Lateral Flow Device' was sent to a server via Mobile Internet and the result appeared on the phone screen after 15 s. RESULTS: A total of 404 faecal samples were analysed. Mean differences of 1.7 mg/kg (range -23.4-20.1) ELISA vs. rapid test scanning, 6.8 mg/kg (-28-14.5) ELISA vs. HT photo and 2.9 mg/kg (-10.3-4.5) rapid test scanning vs. HT photo were found with good agreement calculated using kappa statistic (86%, 87% and 95% respectively). The Coefficients of Variation for HT photo was <10%, with a sensitivity of 96.2% and a specificity of 90.1%. CONCLUSIONS: The new rapid tests are accurate and useful in clinical settings. Feasibility of the home test as part of disease control and self-management is currently being investigated.