Correlation between faecal Calprotectin and Magnetic Resonance Imaging (MRI) in the evaluation of inflammatory pattern in Crohn's disease

Background. Calprotectin, a major cytosolic protein of neutrophils, is increased in inflammatory bowel disease (IBD) and may be considered a suitable marker of intestinal inflammation. Abdominal MRI is becoming more frequently used for the evaluation of IBD patients. Aim of this study was to investigate the role of MRI in IBD for the assessment of disease activity in comparison with faecal calprotectin levels. Patients and Methods. Twenty-four consecutive hospitalized pis (12 F, 12 M, median age: 56; range: 22-77) with a proven diagnosis of CD were studied. At the time of the MRI examination, pts provided a single stool sample for calprotectin measurement. Calprotectin was measured by ELISA (Calprest (R)). Pathological values were considered >50 mu g/g. All pts underwent MRI, performed at 1.5 T, with HASTE T2w with and without fat-saturation, FLASH T1w fat-saturated sequences pre and post iv injection of 0,1 ml/kg of Gadolinium. Presence, degree and length of wall inflammation were evaluated. The MRI degree of wall inflammation was graded with a 0-3 scoring system (0=absent 1=light 2=moderate 3=severe) by considering findings observed on T1 post Gd and T2 fat-suppressed images, as well as the degree of wall thickness. The length of extension was considered as <15 cm, between 15 cm and 30 cm, or >30 cm. Spearman's correlation coefficient was used to evaluated differences in calprotectin levels among the groups obtained by MRI findings. Results. Grade 0 MRI was found in 1 pt with a faecal calprotectin measurement of 206.25 mu g/g; Grade 1 MRI was found in 4 pts with a median faecal calprotectin of 100 mu g/g (5-325); Grade 2 MRI was found in 10 pts with a median faecal calprotectin of 243.75 mu g/g (7.5-606.25); Grade 3 MRI was found in 9 pts with a median faecal calprotectin of 1012.5 mu g/g (30-1268.8). A trend of positive correlation was therefore found between MRI scores of activity and calprotectin levels (p<0.0001) and between MRI scores of thickening of intestinal involvement and calprotectin levels (p=0.005). No apparent correlation was observed between faecal calprotectin concentration and length. Conclusions. Data presenting show that faecal calprotectin levels well correlate with the degree of mucosal inflammation are in agreement with previous studies. Considering the correlation obtained between calprotectin level and MRI findings, we believe that MRI is helpful in assessing and monitoring the degree of disease in Crohn's disease. Clin Ter 2010; 161(2):e53-e56