A new rapid home test for faecal calprotectin in ulcerative colitis

Abstract

Enzyme-linked immunosorbent assay (ELISA) is a time-consuming method for the measurement of faecal calprotectin. Two new quantitative rapid tests have been developed. To compare the new rapid tests with ELISA as 'Gold Standard'. 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. 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%. 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.