Fecal calprotectin may predict endoscopic Crohn's recurrence

Last Updated: 2015-03-20

By Larry Hand

NEW YORK (Reuters Health) - Measuring fecal calprotectin (fCal) in asymptomatic patients with Crohn's disease may be an effective way to monitor these patients for endoscopic recurrence after ileocolonic resection, French researchers say.

"I think that our results are solid enough and convincing to allow changing our clinical practice on the postoperative follow-up of patients with Crohn's disease, since in our large cohort, a low fecal calprotectin level was highly predictive for the absence of endoscopic postoperative recurrence," Dr. Stephane Nancey, head of gastroenterology at University Hospital of Lyon, told Reuters Health by email.

Dr. Nancey and colleagues analyzed data on 86 asymptomatic CD patients who had ileocolonic resections within 18 months and who underwent ileocolonoscopy and provided blood and stool samples at three tertiary clinics.

Forty-three patients (50%) were in remission, 16 patients (18.6%) had moderate recurrence, and 27 (31.4%) had severe recurrence, the researchers reported online March 17 in the American Journal of Gastroenterology.

Mean fCal concentrations were significantly higher for patients with recurrence compared with patients in remission (473 vs. 115 mcg/g, p<0.0001). fCal concentrations were correlated with severity according to the Rutgeerts score, the authors found.

They also found a "weak but significant" difference in high-sensitivity C-reactive protein (hsCRP) concentrations between recurrence and remission cases. Those, too, correlated with Rutgeerts scores.

The researchers then calculated optimal cutoff points for fCal and hsCRP for assessing for recurrence or remission. They used a cutoff point of 100 mcg/g as the upper limit for fCal and 1 mg/L as an upper limit for hsCRP.

Applying those cutoff points to the study population, they found the overall accuracy for distinguishing recurrence from remission was better for fCal at 77% than for hsCRP at 53%. They calculated only two patients (4.7%) in recurrence had fCal concentrations <100 mcg/g, but eight patients (18.6%) with hsCRP concentrations of 1 mg/L were in recurrence.

They say the exclusive measuring of fCal could have stratified "the vast majority" of patients having no sign of recurrence and allowed avoidance of 25 colonoscopies (about 30%), compared with 11 colonoscopies (13%) that might have been avoided by measuring just hsCRP.

"A substantial proportion of colonoscopy . . . may be replaced by the simple and noninvasive measurement of fCal, as this marker had an excellent (negative predictive value) for predicting endoscopic recurrence in the postoperative setting," the researchers wrote.

They conclude, "Measuring fCal after intestinal resection could identify asymptomatic patients with a genuine endoscopic recurrence and could allow avoiding some colonoscopies when fCal is below the cutoff" of 100 mcg/g.

"In contrast, when fecal calprotectin is found over 100 mcg/g, it remains important to perform a colonoscopy in order to assess the severity of endoscopic recurrence and adapt therapies accordingly," Dr. Nancey told Reuters Health.

"In addition, our results have been just confirmed by another independent Australian group (Wright EK: http://1.usa.gov/1I63S7q). We both defined the same optimal threshold of fecal calprotectin as 100 mcg/g of stool capable to accurately discriminate patients with or without endoscopic recurrence," Dr. Nancey added.

"Our study has to be extended by investigating other noninvasive tools associated with fecal calprotectin," he continued. "The future might be to change the monitoring of CD patients in the postoperative setting. Fecal calprotectin could be measured by point of care (by the patient himself at home) at a regular basis. We also have to assess the cost-effectiveness of this strategy to avoid endoscopic, clinical, and surgical recurrence."

The authors reported no external funding or disclosures.

SOURCE: http://bit.ly/1LA8hF6

Am J Gastroenterol 2015.