P245 Accuracy of fecal M2-Pyruvate Kinase compared with fecal calprotectin to assess endoscopic severity in patients with inflammatory bowel diseases
G. Boschetti*1, S. Boyer1, M. Chauvenet1, K. Stroeymeyt1, N. Benech1, J. Drai2, B. Flourié1, S. Nancey1
1Lyon-Sud Hospital, Gastroenterology, Pierre-Benite, France, 2Lyon-Sud Hospital, Biochemistry, Pierre Benite, France
M2-Pyruvate Kinase (M2-PK) is a key dimeric enzyme involved in the glycolytic pathway and expressed in undifferentiated and proliferating tissues. Fecal M2-PK levels are increased in case of gut inflammation and therefore might represent a promising marker in inflammatory bowel diseases (IBD). We performed a head-to-head comparison of diagnostic accuracy of fecal M2-PK (fM2-PK) and fecal calprotectin (fCal) in predicting endoscopic disease severity in ulcerative colitis (UC) and Crohn's disease (CD).
A total of 78 consecutive patients with IBD (26 UC and 52 CD) undergoing an ileo-colonoscopy were prospectively enrolled. All patients provided fecal samples for fCal (Bühlmann) and fM2-PK (Schebo Biotech) measurements. Endoscopic disease activities were scored independently according to the SES-CD score and the Rachmilewitz index, respectively for CD and UC (active disease defined as both scores >2 points). Accuracies of both fecal markers were determined using AUROC curves and sensitivities (Sen), specificities (Spe), predictive values (PV) and overall accuracies (OA) were also assessed at adjusted cutoffs determined by the ROC curves. Spearman rank correlations were also calculated.
Whereas fM2-PK concentrations did not differ between endoscopically active and inactive CD patients, levels of fM2-PK were significantly higher in active UC when compared with those measured in inactive UC patients. In contrast, fCal concentrations differed significantly both in patients with active CD and UC when compared with those in patients with inactive disease. Accuracies of fM2-PK and fCal to predict endoscopic activity were higher in UC (AUROC 0.95 and 0.93, respectively) compared with those in CD (AUROC 0.60 and 0.80, respectively). fM2-PK concentrations were significantly correlated with endoscopic severity scores in UC and at a lesser degree in CD (correlation coeff r=0.75 (p<0.001) and r=0.37 (p=0.006); respectively). In addition, fM2-PK and fCal concentrations were also significantly correlated for UC (r=0.83, p<0.001) and for CD (r=0.43, p=0.001). Sen, Spe, PV and OA of both fecal markers are summarized in Table1.
fM2-PK is a reliable, surrogate and promising marker, as or even more accurate as fCal, to identify UC patients with endoscopic active disease.