Common Crohn's Disease Index Lumps in Irritable Bowel Syndrome Patients

Though the Crohn's disease activity index (CDAI) is commonly applied in large Crohn's disease clinical trials to distinguish symptoms resulting from inflammation, a study published online Feb. 21 in Alimentary Pharmacology and Therapeutics demonstrated the index does not differentiate between active Crohn's disease patients and patients with the non-inflammatory irritable bowel syndrome (IBS).

Though the Crohn’s disease activity index (CDAI) is commonly applied in large Crohn’s disease clinical trials to distinguish symptoms resulting from inflammation, a study published online Feb. 21 in Alimentary Pharmacology and Therapeutics demonstrated the index does not differentiate between active Crohn’s disease patients and patients with the non-inflammatory irritable bowel syndrome (IBS).

In their “The Crohn’s Disease Activity Index Is Similarly Elevated in Patients with Crohn’s Disease and in Patients with Irritable Bowel Syndrome” analysis, Conor Lahiff, MB, MD, and researchers at the Center for Inflammatory Bowel Disease at the Beth Israel Deaconess Medical Center, in Boston, compared CDAI total scores and CDAI component scores in 44 Crohn’s disease patients and 47 IBS patients over a six-month period from September 2010 to March 2011. Based on the patients’ CDAI scores, the investigators found 62 percent of the IBS group qualified as active Crohn’s disease and 32 percent met the parameters of moderate to severe Crohn’s disease, while 50 percent and 15 percent of the Crohn’s disease group, respectively, matched those score levels.

The researchers noted the CDAI’s measures of subjective and non-inflammatory symptoms — specifically abdominal pain, wellbeing and stool frequency — significantly elevated scores in the IBS patients, while objective measures — such as C-reactive protein and CDAI haematocrit — better identified gut inflammation, which is a distinguishing feature of inflammatory bowel disease (IBD) such as Crohn’s disease.

“These findings show that functional gastrointestinal symptoms, which are common in IBD, can affect CDAI scores, producing levels that could impact clinical trials and how we treat our patients,” the authors wrote. “Objective markers should enable clearer differentiation between inflammatory and non-inflammatory symptoms and facilitate reproducible assessment of disease activity in Crohn’s (disease) for use in future clinical trials.”

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