Faecal lactoferrin--a novel test to differentiate between the irritable and inflamed bowel?

Distinguishing between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) can be challenging.

To investigate the utility of faecal lactoferrin as a marker of inflammation in patients with IBD, IBS and controls.

Disease activity in IBD patients was assessed using the modified Harvey-Bradshaw Activity Index. Stool samples were analysed using an ELISA assay.

We recruited 137 patients with IBS, 126 with ulcerative colitis (UC) and 104 with Crohn's disease (CD), and 98 healthy volunteers. The median +/- IQ lactoferrin concentration (microg/g faecal weight) was 0 +/- 1.4 for IBS patients, 6.6 +/- 42 for UC patients, 4 +/- 12.7 for CD patients and 0.5 +/- 2 for healthy controls. Lactoferrin levels were significantly higher in IBD patients compared with IBS/healthy controls (P < 0.001). The median lactoferrin concentrations were significantly higher in active UC & CD patients compared with inactive patients (P < 0.001 and P = 0.002 respectively). The sensitivity, specificity, positive and negative predictive values of lactoferrin in distinguishing active IBD from IBS/healthy controls were 67% and 96%, 87% and 86.8% respectively.

Lactoferrin is useful to differentiate between IBD and IBS, and can be used as an adjunct to blood parameters to determine IBD patients who have ongoing inflammation.