Fecal calprotectin and endoscopic scores: The cornerstones in clinical practice for evaluating mucosal healing in inflammatory bowel disease

Table 4 Practical pearls for the use of fecal calprotectin in Crohn’s disease

FC is a reliable test in distinguishing patients with IBD from those with IBS. A cutoff of ≤50 μg/g appears to have a better sensitivity and a negative predictive value of > 95% for IBD in Western countries[18]

FC should be measured before starting or optimizing any therapy for CD, at the end of the induction phase, every 2–4 mo in patients being treated for active disease, and every 6–12 mo during the maintenance therapy in those in symptomatic remission; and in case of clinical relapse of disease[14,20]

In patients with CD in symptomatic remission with confirmation of endoscopic remission within the last 3 years, an FC of < 150 µg/g can reliably rule out active inflammation and avoid routine endoscopic reassessment with relatively low false negatives[20]

Where there is a symptom-biomarker disconnect, or in patients with mild symptoms, an FC value of > 150 µg/g is insufficient to identify endoscopically active inflammation. In this context, endoscopic or radiologic assessment is necessary to truly define the presence of active disease before making empiric treatment adjustments[20]

In the presence of moderate to severe symptoms, an elevated FC strongly suggests endoscopically active disease and can be used to make decisions regarding most changes in therapy. However, normal FC is insufficient to dismiss inflammation, and endoscopic or radiologic assessment is important in this setting[20]

In small bowel CD, where only a short segment of involvement may exist, as well as in relatively proximal disease (upper gastrointestinal, stomach, and esophagus), the FC concentrations may not be elevated to that degree and produce false negatives[57]

Many times, FC is highly effective in detecting endoscopic ulcerations regardless of the CD location. A cutoff value of > 200 μg/g in patients with isolated ileal involvement and > 250 μg/g for ileocolonic or colonic disease may be the optimal threshold to detect endoscopic ulcerations[90]

Normalization of FC (e.g., < 250 μg/g) within 12 mo of starting therapy is associated with a reduced risk of CD progression[91]

In patients with CD in surgically induced remission within the past 12 mo at a low risk of postoperative recurrence, an FC value of < 50 μg/g reliably rules out postoperative recurrence. In patients at high risk (e.g., smokers, more than one intestinal resection, surgery due to penetrating disease, perianal disease, and long segments of small bowel resection), FC cannot be used to rule out or confirm endoscopic recurrence[20]

After ileocecal resection, an FC cutoff value of > 150 μg/g is likely to have the best overall accuracy in predicting postoperative endoscopic recurrence, with a sensitivity of approximately 70%[92]

FC concentration from an ileostomy effluent can be used for assessing and monitoring small bowel inflammation and disease recurrence. An FC level of > 60 μg/g is strongly suggestive of the presence of small bowel inflammation[93]

Adapted from Dajti et al[18], Kapel et al[14], Ananthakrishnan et al[20], D'Amico et al[57], Buisson et al[90], Plevris et al[91], Tham et al[92], and Daoud et al[93]. CD: Crohn’s disease; FC: Fecal calprotectin; IBD: Inflammatory bowel disease; IBS: Irritable bowel syndrome.