Does fecal calprotectin predict relapse in patients with Crohn's disease and ulcerative colitis?

BACKGROUND AND AIMS: An evaluation is made of the utility of fecal calprotectin in predicting relapse in patients with inflammatory bowel disease (IBD). The possible differences in its predictive capacity in Crohn's disease (CD) versus ulcerative colitis (UC), and the different phenotypes, are also examined. METHODS: This is a prospective study with 135 patients diagnosed with IBD in clinical remission for at least 3 months. The patients submitted a stool sample within 24 hours after the baseline visit, for the measurement of fecal calprotectin. All patients were followed-up on for one year. RESULTS: Sixty-six patients had CD and 69 UC. Thirty-nine (30%) suffered from relapse. The fecal calprotectin concentration was higher among the patients with relapse than in those that remained in remission: 444 µg/g (95% CI 34-983) versus 112 µg/g (95% CI 22-996); p<0.01. Patients with CD and calprotectin>200 µg/g relapsed 4 times more often than those with lower marker concentrations. In UC, calprotectin>120 µg/g was associated with a 6-fold increase in the probability of disease activity outbreak. The predictive value was similar in UC and CD with colon involvement and inflammatory pattern. In this group, calprotectin>120 µg/g predicted relapse risk with a sensitivity of 80% and a specificity of 60%. Relapse predictive capacity was lower in patients with ileal disease. CONCLUSIONS: Fecal calprotectin may be a useful marker for predicting relapse in patients with IBD. Its predictive value is greater in UC and CD with colon involvement and inflammatory pattern, compared with ileal CD.