Changes in Fecal Calprotectin Reflect Clinical Response in Treatment of an Acute Flare of Inflammatory Bowel Disease

Introduction: Fecal calprotectin (FC) is a noninvasive biomarker of inflammation used to predict relapse and monitor remission in inflammatory bowel disease (IBD). Physicians currently measure FC values to track patients’ inflammatory status. We evaluated how intensive therapy for an acute flare of IBD impacts FC immediately following treatment.

Methods: In a prospective pilot study, we evaluated adults with an IBD flare requiring escalation in therapy. A modified partial Mayo Score for ulcerative colitis (UC) (0-3 stool frequency and 0-3 rectal bleeding, max score = 6) and modified Harvey Bradshaw score for Crohn’s disease (CD) (0-2 for pain, diarrhea, fever, fistula, and extra-intestinal manifestations, max score = 10) assessed symptom severity pre- and post-treatment. Initial FC was obtained prior to initiation of therapy and again after acute management of the flare. Escalation in therapy consisted of initiation or increase in steroids, initiation or change in biologics, or surgery. IRB approval was granted and T-tests were used for analyses.

Results: Of the 28 enrolled patients, 23 were hospitalized. Mean age was 39 years and 64% were men. Thirteen (46%) patients had UC and 15 (54%) had CD. In UC, mean FC decreased from 838 μg/g to 523 μg/g over median 9 days. Mean pre-treatment modified Mayo score was 3.82 and mean post-treatment score was 0.64. In CD, mean FC decreased from 815 μg/g to 651 μg/g over median 14 days. Mean pre-treatment modified Harvey Bradshaw score was 4.11 and mean post-treatment score was 1.44. In patients who received surgery (n=4, all with CD), mean FC decreased from 988 μg/g to 401 μg/g over median 23 days. In patients with perianal disease (n=4), mean FC declined from 1154 μg/g to 869 μg/g over median 11 days. In those patients with a decline in FC (16; 8 with UC, 8 with CD), severity of symptoms declined by an average of 2.25 modified Mayo points in UC and 3.0 modified Harvey Bradshaw points in CD.

Discussion: FC rapidly declined in the majority of patients in our study and correlated with improving symptom severity scores. FC declined most significantly in patients undergoing surgery. The average decline in FC was greater in UC patients than in CD patients. FC may be employed as a noninvasive biomarker of response to acute therapy in patients with severe IBD flares.

Keywords: fecal calprotectin, IBD flare, biomarkers.