Significance Of Serum Calprotectin In Assessing Inflammatory Bowel Disease Activity

Background: Inflammatory bowel disease(IBD)is a chronic,non-specific,inflammatory bowel disorder,including crohn's disease and u1 cerative colitis.However,its pathogenesis is unclear.Its recurrent characteristics seriously affect the quality of life and mental health of patients.Timely identification of disease activity can guide the treatments and prognosis.The current criteria for the diagnosis of IBD and accurate judgment of disease activity are mainly endoscopic and biopsy,which characterized by invasive,time consuming and high cost.In addition,the need for intestinal cleaning bring pains to the patients.Therefore,there is a need for a convenient,economical and reliable marker to monitor IBD disease activity.Calprotectin is widely distributed in various kinds of cells,tissues and body fluids,which is the main protein of neutrophils and macrophages.As an inflammatory marker,it can be released after the activation of neutrophils and macrophages.Objective: To investigate the application value of serum calprotectin level in assessing the activity of IBD.Methods: One hundred and seventy IBD patients including eighty-five crohn's disease and eighty-five ulcerative colitis patients at Suzhou municipal hospital(north branch)from August 2015 to January 2017 were enrolled in this study,and eighty-five healthy subjects were served as controls.Serum calprotectin level was determined by enzyme linked immunosorbent assay(ELISA).We compared the differences of serum calprotectin levels among the IBD group and control group.Besides that,we compared the differences of serum calprotectin levels in different periods of IBD patients.The correlations of serum calprotectin level with clinical features of IBD were analyzed.The diagnostic efficacies for CD and UC were assessed by receiver operating characteristic(ROC)curve.Results: The serum calprotectin level was significantly higher in IBD patients than in healthy controls(P<0.001).There were significant differences in serum calprotectin levels among CD and UC activity staging groups(mild activity,moderate activity,severe activity and remission)(P<0.05).Positive correlations were found between serum calprotectin level and CRP,ESR,fecal calprotectin level of IBD patients(?=0.341,P<0.001;?=0.438,P<0.001;?=0.542,P<0.001,respectively).Besides,positive correlations were found between serum calprotectin level with disease activity index(CDAI or Mayo sore)of IBD patients(?=0.309,P=0.004;?=0.227,P=0.036,respectively).Nevertheless,no correlations between serum calprotectin level with location of IBD and disease subtypes(P>0.05).The serum calprotectin levels in IBD group were not related to gender and age(P>0.05).The area under curve(AUC)of serum calprotectin for diagnosis of CD and UC were 0.946 and 0.906,respectively.To serum calprotectin level at 412.98ng/ml as the cut-off value,the specificity and sensitivity in the diagnosis of CD were 85.9% and 90.6%,respectively.To serum calprotectin level at 506.49ng/ml as the cut-off value,the specificity and sensitivity in the diagnosis of UC were 96.5% and 76.5%,respectively.Conclusions: Serum calprotectin level is associated with the activity of IBD.As a result,serum calprotectin level may has the potential to be served as a clinical index of IBD activity.