Faecal calprotectin, lactoferrin, M2-pyruvate kinase and S100A12 in severe ulcerative colitis: a prospective multicentre comparison of predicting outcomes and monitoring response

Objective To compare four faecal markers for their ability to predict steroid refractoriness in severe paediatric ulcerative colitis (UC). Construct validity and responsiveness to change were also assessed. Methods This was a prospective multicentre cohort study. Stool samplesfrom 101 children (13.3±3.6 years; Pediatric UC Activity Index (PUCAI) at admission 72±12 points) were obtained at the third day of intravenous steroid therapy. Repeated samples at discharge were obtained from 24 children. Predictive validitywas assessed using diagnostic utility statistics to predict steroid failure (ie, the need for salvage treatment). Concurrent validitywas assessed using correlational analysis with the following constructs: PUCAI, Lindgren and Seo scores, physician9s global assessment, albumin, erythrocyte sedimentation rate and C-reactive protein (CRP). Responsiveness was assessed using test utility and correlational strategies. Results Median values (IQR) were very high at baseline for all four markers ( calprotectin4215 μg/g (2297–8808); lactoferrin212 μg/ g( 114–328); M2- pyruvate kinase(M2-PK) 363 U/g (119–3104); and S100A12 469 μg/g (193–1112)). M2-PK was numerically superior to the other three markers and CRP in predicting response to corticosteroid treatment (area under the receiver operating characteristic (ROC) curve 0.75 (95% CI 0.64 to 0.85; p 0.05, area under the ROC curve 0.05). Conclusions The four markers were greatly elevated in severe paediatric UC. Only M2-PK had good construct and predictive validity, and none was responsive to change. The PUCAI, a simple clinical index, performed better than the faecal markers in predicting outcome following a course of intravenous corticosteroids in severe UC.