Fecal calprotectin is a marker of inflammation in inflammatory bowel disease (IBD).
Mucosal healing has become a goal of treatment in IBD.
Dr Geert D'Haens and colleagues from the Netherlands examined how reliably calprotectin levels reflect mucosal disease activity.
In all, 126 IBD patients and 32 irritable bowel syndrome (IBS) patients needing colonoscopy delivered a sample of feces prior to the start of bowel cleansing.
Besides collection of symptom scores and blood tests, experienced endoscopists recorded the Simple Endoscopic Score for Crohn's Disease (SES-CD) and the Crohn's Disease Endoscopic Index of Severity (CDEIS) in Crohn's disease patients and the Mayo endoscopic score in ulcerative colitis patients.
Stool samples were shipped for central calprotectin PhiCal Assay.
Correlation analysis was done with Pearson statistics.
The researchers found that the median fecal calprotectin levels were 175 μg/g in Crohn's disease, 465 μg/g in ulcerative colitis, and 54 μg/g in IBS.
Correlations were significant with endoscopic disease scores in both Crohn's disease and in ulcerative colitis.
Using ROC statistics, a cutoff value of 250 μg/g indicated the presence of large ulcers with a sensitivity of 60%, and a specificity of 80% in Crohn's disease.
The team found that levels 250 μg/g or less predicted endoscopic remission with a 94% sensitivity, and a 62% specificity.
In ulcerative colitis, a fecal calprotectin of more than 250 μg/g gave a sensitivity of 71%, and a specificity of 100% for active mucosal disease activity.
The research team observed that calprotectin levels significantly correlated with symptom scores in ulcerative colitis, but not in Crohn's disease.
Dr D'Haens' team concludes, "Fecal calprotectin levels correlate significantly with endoscopic disease activity in IBD."
"The test appears useful in clinical practice for assessment of endoscopic activity and remission."