Lactoferrin is a 76kDa iron-binding glycoprotein of the transferrin family. It is synthesised and stored in the secondary granules of neutrophils and is also present in several secretory fluids, including milk, colostrum, saliva, tears, and nasal secretions.
Lactoferrin exists in different polymeric forms ranging from monomers to tetramers and tends to polymerise especially at high concentrations. Physiologically, lactoferrin is involved in the regulation of iron homeostasis, as well as innate immunological defence activities against a broad range of microbes, inflammatory activity, regulation of cellular growth and differentiation and protection against cancer development and metastasis. Lactoferrin is able to interact both with molecular and cellular components to exert its effects.
During intestinal inflammation, polymorphonuclear neutrophils infiltrate the mucosa and release lactoferrin by degranulation, which results in an increased excretion of lactoferrin into the lumen which subsequently becomes incorporated into faeces. Faecal lactoferrin is a well-established biomarker for neutrophilic intestinal inflammation.
Faecal lactoferrin measurement supports the following:
Detection of intestinal inflammation
Monitoring of disease activity in inflammatory bowel disease (IBD)