Lactoferrin
Lactoferrin is an iron binding protein, which is present in high concentration in neutrophils, but may also be secreted by most mucosal epithelial cells. During intestinal inflammation, leukocytes migrate to the mucosa and infiltrate the intestinal lumen, increasing the level of fecal lactoferrin.
Lactoferrin levels are higher in patients with Inflammatory bowel disease (IBD) than in patients with active irritable bowel syndrome, which does not involve intestinal inflammation. Several studies have demonstrated that lactoferrin has a sensitivity of 56-100%, specificity of 61-100%, positive predictive value of 59-100% and negative predictive value of 78-99% in distinguishing inflammatory bowel disease from irritable bowel syndrome.
Lactoferrin levels correlate well with clinical, endoscopic and histologic grading of inflammatory bowel disease activity. Patients with active disease have higher levels than those with inactive disease. Insufficient studies are available to determine the usefulness of lactoferrin in monitoring therapy or predicting relapse of disease
Increased lactoferrin is not specific for inflammatory bowel disease. Fecal levels may be increased in bacterial or viral gastroenteritis, food intolerance, nonsteroidal enteropathy, colorectal cancer and after pelvic irradiation
Lactoferrin is measured by a qualitative enzyme linked immunoassay. Specimen requirement is 1 gram of fresh, unpreserved stool or stool preserved in Cary-Blair transport media. Lactoferrin is stable in stool for at least 48 hours.
Reference range is negative.
Other stool tests for gastrointestinal inflammation include fecal leukocytes and calprotectin.
Lehmann FS, et al, The role and utility of faecal markers in inflammatory bowel disease. Ther Adv Gastroenterol. 2015;8(1)23-36.
