Faecal calprotectin and lactoferrin are reliable surrogate markers of endoscopic response during Crohn's disease treatment.

Objective. Serial monitoring data for faecal calprotectin and lactoferrin during Crohn's disease (CD) therapy are scarce. The aim of this research was to study the behaviour of faecal biomarkers during CD therapy. Material and methods. Adult CD patients (n = 19) needing therapy enhancement were prospectively recruited. The simple endoscopic score for Crohn's disease (SES-CD) was administered before and 4-6 months after therapy. At baseline and at 2-3 and 4-6 months, patients provided faecal samples for measurements of calprotectin and lactoferrin. Results. Of 19 patients, seven were endoscopic responders, three were partial responders and nine were non-responders. During therapy, both faecal-biomarker concentrations decreased significantly in responders: median calprotectin from 1282 mu g/g (range 156-2277 mu g/g) to 73 mu g/g (range 7-2222; P = 0.005) and lactoferrin from 233 mu g/g (range 2.8-802 mu g/g) to 0.0 mu g/g (range 0.0-420 mu g/g; P = 0.005), and these changes correlated significantly with changes in the SES-CD. In non-responders, changes in faecal biomarkers were non-significant: calprotectin decreased from 1017 mu g/g (range 53-3928 mu g/g) to 223 mu g/g (range 35-15 330 mu g/g; P = 0.594) and lactoferrin from 22.5 mu g/g (range 2.1-629 mu g/g) to 13.0 mu g/g (range 3.5-1259 mu g/g; P = 0.515). Conclusions. The faecal neutrophil-derived proteins calprotectin and lactoferrin are reliable surrogate markers of mucosal improvement. Endoscopic responders achieved normalization of faecal biomarkers, whereas in the majority of endoscopic non-responders these markers remained abnormal.