CRP, calprotectin excludes IBD in patients with IBS symptoms
Adding C-reactive protein and fecal calprotectin to symptom-based diagnostic criteria may help to rule out inflammatory bowel disease in patients with symptoms of irritable bowel syndrome, according to new research data.
“Though IBD is uncommon in patients with typical IBS symptoms and no alarming features, patients and providers remain concerned about this possibility,” William D. Chey, MD, AGAF, FACG, FACP, from the University of Michigan Health System, told Healio Gastroenterology.
William D. Chey
Chey and colleagues performed a systematic review and meta-analysis to assess the utility of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fecal calprotectin and fecal lactoferrin to aid in differentiating between IBS, IBD and healthy patients. After reviewing 1,252 relevant studies, 12 involving 1,059 IBD patients (52.7% male; mean age, 40.7 ± 13.3 years), 595 IBS patients (29.9% male; mean age, 40 ± 18.2 years) and 491 healthy controls (53.5% male; mean age, 38.7 ± 13.8 years) were included in the meta-analysis.
The researchers found that none of the biomarkers could distinguish patients with IBS from healthy controls, but CRP and calprotectin had some value in distinguishing IBD from IBS or healthy controls. High CRP was predictive of IBD, while low CRP indicated the absence of IBD; CRP ≥ 1.7 mg/dl and > 2.7 mg/dl indicated > 52% and > 90% likelihood of IBD, respectively, while CRP ≤ 0.5 indicated that the probability of having IBD was 1% or less.
Likelihood of IBD also increased with calprotectin level, which had a maximal predictive value of 78.7% at 1,000 µg/g. Patients with < 40 µg/g calprotectin had ≤ 1% chance of having IBD. However, calprotectin level could not rule out IBS entirely; on both sides of the fecal calprotectin range (20 µg/g - 1,000 µg/g) there was an 11.6% and 7.6% predictive probability of IBS, respectively, with a peak predictive probability of 280 µg/g (18.8%).
“Serum CRP and fecal calprotectin provide a noninvasive means by which to exclude IBD in patients with IBS symptoms and no alarming features,” Chey said.
“Based upon these results, it may be reasonable for clinicians to consider ordering CRP or fecal calprotectin to improve their confidence in making a diagnosis of IBS,” the researchers concluded, adding that “prospective studies to evaluate the clinical utility and cost effectiveness of adding CRP or fecal calprotectin to the evaluation of patients with suspected IBS in different populations would be of considerable interest.” – by Adam Leitenberger
Disclosures: Chey reports he is a consultant for Salix Pharmaceuticals. The other researchers report no relevant financial disclosures.