26854 Lactoferrin, Feces (LCTF)

LCTF, FLACT, Fecal, Feces, Stool​

Evaluating patients suspected of having a gastrointestinal inflammatory process.​

Distinguishing inflammatory bowel disease from irritable bowel syndrome, when used in conjunction with other diagnostic modalities, including endoscopy, histology, and imaging.

Preferred shipping temperature is frozen. Refrigerated or thawed specimens received more than 72 hours after collection will be rejected

Collect a fresh random fecal specimen, no preservatives.

If specimen is sent refrigerated, send immediately after collection.

If specimen cannot be sent immediately, freeze specimen and send frozen.

Separate specimens must be submitted when multiple tests are ordered, with the exception of ELASF / Pancreatic Elastase, Feces and CALPR / Calprotectin, Feces. If only a single specimen is collected, it must be split prior to transport.

Testing cannot be added on to a previously collected specimen.

​Specimens collected from diapers

​Elevations in fecal lactoferrin are not diagnostic for inflammatory bowel disease (IBD), and normal fecal lactoferrin concentrations do not exclude the possibility of IBD. Diagnosis of IBD should be based on clinical evaluation, endoscopy, histology, and imaging studies. 

Elevations in fecal lactoferrin may be observed in other disease states associated with neutrophilic inflammation of the gastrointestinal system, including celiac disease, colorectal cancer, and gastrointestinal infections.

Falsely decreased concentrations of fecal lactoferrin may be observed in patients with neutropenia or granulocytopenia.

Due to the lack of homogenous distribution of lactoferrin in fecal material, variability in results may be seen when patients are monitored over time, particularly in samples with high lactoferrin concentrations.

Bovine lactoferrin (found in dairy products) has a different molecular structure from human lactoferrin and is not detected in this assay. However, nursing infants and those taking human lactoferrin supplements may risk false-positive results.(5)

Lactoferrin is an iron-binding glycoprotein belonging to the transferrin family. Lactoferrin is primarily stored in the secondary granules of neutrophils as well as monocytes, macrophages and epithelial cells.(1,2) Lactoferrin has multiple roles in host defense with antimicrobial, anti-inflammatory, and immunomodulatory properties and is released through active secretion from living cells rather than cell death.(3) Lactoferrin reversibly binds ferric (Fe[3+]) iron,(2) inhibiting the growth of iron-dependent bacterial species.

 Fecal lactoferrin is a stable biomarker, resistant to proteolysis and environmental degradation for several days, making it suitable for non-invasive assessment of intestinal inflammation. Fecal lactoferrin is the most specific (96.5%) biomarker to distinguish irritable bowel syndrome (IBS) from inflammatory bowel disease (IBD), and nearly as sensitive (81.5%) as fecal calprotectin (85%).(4) In cases where the calprotectin result is borderline, fecal lactoferrin results may provide additional context for clinicians in the diagnosis and monitoring of IBD. Measurement of fecal lactoferrin and fecal calprotectin may reduce the need for invasive procedures like colonoscopy for the monitoring of IBD patients. The American Gastroenterological Association includes both fecal calprotectin and lactoferrin in their recommendations for the application of biomarkers in the management of ulcerative colitis.(5)

Because lactoferrin is a non-specific inflammatory biomarker, elevated concentrations can also be found in patients with celiac disease, colorectal cancer, gastrointestinal surgery, and gastrointestinal infections such as Clostridioides difficile.(5) Increased concentrations of fecal lactoferrin are not diagnostic for IBD and must be interpreted along with clinical symptoms and endoscopic findings.(4)

​Lactoferrin concentrations at or below 4.4 mcg/g are not suggestive of an active inflammatory process within the gastrointestinal system. For patients experiencing gastrointestinal symptoms, consider further evaluation for functional gastrointestinal disorders.

 Fecal lactoferrin concentrations above 4.4 mcg/g are suggestive of an active inflammatory process within the gastrointestinal system. Additional diagnostic testing to determine the etiology of the inflammation is suggested.