The diagnostic usefulness of fecal lactoferrin in the assessment of Crohn's disease activity

Background: Diagnosis and monitoring of Crohn's disease (CD) is difficult and time-consuming. In recent years, diagnostic usefulness of fecal calprotectin has been proven. However, data on the utility of other fecal markers are scarce.

Aims: To evaluate the usefulness of fecal lactoferrin (FL) in the assessment of CD activity.

Methods: The group consisted of 101 CD patients (median age: 30 years, IQR: 24-37). FL was measured in a single stool sample by using the immunoenzymatic methods. The clinical activity of the disease was evaluated by using the Crohn's Disease Activity Index (CDAI). Depending on the location of the disease, either a colonoscopy or magnetic resonance enterography was performed or both in order to evaluate the disease activity by using appropriate endoscopic and enterographic scores.

Results: Median FL concentration was 84.14 (IQR: 36.4-302.9) μg/ml and it correlated with C-reactive protein concentration (p=0.0000001, r=0.5), CDAI (p=0.002, r=0.3) and colonic Simple Endoscopic Score for Crohn's Disease (SES-CD) (p=0.000004, r=0.5). Assuming endoscopic remission in the large intestine with colonic SES-CD≤3 points, a ROC curve showed that FL concentration of 145.82 μg/ml had 84.6% sensitivity and 60.5% specificity in discriminating CD patients with endoscopically active and inactive disease [AUC: 0.676 (95% CI: 0.531-0.8), (p=0.0347)]. The positive predictive value for this concentration was 42% and negative predictive value -92%.

Conclusions: FL is a sensitive marker of CD activity and it reliably reflects the mucosal inflammatory lesions in large intestine. Thus, it can be helpful in diagnostics and monitoring of CD.