Clinical Utility of Fecal Calprotectin Monitoring in Asymptomatic Patients with Inflammatory Bowel Disease
We read with interest the article by Anke Heida evaluating the usefulness of repeated fecal calprotectin (FC) measurements to predict inflammatory bowel disease (IBD) relapses by a systematic literature review.1 The author found that 2 consecutively elevated FC values are highly associated with disease relapse, indicating a consideration to proactively optimize IBD therapy plans. Because their findings are important to current practices, several questions deserve attention.
It would be valuable for gastroenterologists if repeated measurements of FC could help predict flares in asymptomatic patients with IBD. But it is an important issue whether FC has sufficient sensitivity and specificity to detect these lesions in asymptomatic patients with IBD. The predictive value of FC in assessing the disease relapse of patients with IBD has been debated because of inconsistent results in some studies, because these studies have set the different FC cutoff levels. For example, a study by Rocio Ferreiro-Iglesias showed that FC levels <130 μg/g are consistently associated with maintained disease remission, whereas concentrations >300 μg/g allow for predicting relapse with a high probability at any time over the following 4 months.2 But the study by Mooiweer E showed that FC <56 mg/kg was found to optimally predict absence of relapse during follow-up with 64% sensitivity and 100% specificity.3 A study by Gisbert JP showed that FC >150 μg/g may be useful in predicting clinical relapse with 69% sensitivity and 69% specificity.4 A study by Walkiewicz D showed that FC >400 μg/g may be useful in predicting impending clinical relapse.5 In fact, there will be some degree of variability based on disease activity in patients with IBD. Therefore, the issue of intraindividual variability must be considered in the role of FC to predict relapse in asymptomatic patients with IBD.
In conclusion, FC has a potential role in predicting the clinical relapse of asymptomatic patients with IBD. And the combination use of other fecal markers such as fecal lactoferrin, polymorphonuclear neutrophil elastase based on patient characteristics could improve the sensitivity and specificity. Future studies are needed to evaluate whether disease activity monitoring by FC and other fecal markers could improve the predictive value in assessing the clinical relapse of asymptomatic patients with IBD.