Gut
Lactoferrine
An inflammation protein from white blood cells in the stool; similar to calprotectin, but without a fixed cut-off value.
Everything about this testWhat it measures
Lactoferrin is a protein found in, among other places, white blood cells (neutrophilic granulocytes). When the bowel wall is inflamed, many of these cells end up in the gut, and with them lactoferrin in the stool. The test measures how much lactoferrin is in a stool sample. It works in the same way as calprotectin, another inflammation marker in stool.
- Inflammation of the bowel wall, for example with a gut infection or chronic inflammatory bowel disease (IBD) such as Crohn's disease or ulcerative colitis
High
A raised lactoferrin points to inflammatory cells in the gut. This may fit chronic inflammatory bowel disease such as Crohn's disease or ulcerative colitis, especially with long-lasting diarrhea, blood or mucus in the stool and weight loss. A raised value also occurs with a bacterial gut infection and with use of anti-inflammatory painkillers (NSAIDs). In breastfed babies the value is higher, because breast milk contains a lot of lactoferrin. Rarely: a bowel polyp or bowel cancer.
Low
A low value makes active inflammation of the bowel wall less likely. With recurring abdominal pain and changing bowel habits, this more likely fits irritable bowel syndrome. For ruling out chronic inflammatory bowel disease, the cut-off values of calprotectin are better established than those of lactoferrin.
If your result is abnormal
With a raised value and bowel symptoms, the GP usually requests calprotectin in the stool, because the referral thresholds in the guideline are based on it. A raised calprotectin is followed by referral to a gastroenterologist.
Reliability
Lactoferrin in stool measures roughly the same as calprotectin and in research is also useful for distinguishing bowel inflammation from an irritable bowel. For calprotectin, cut-off values have been set for this question; for lactoferrin there is no agreed cut-off value, which makes a slightly raised value harder to interpret. The test does not say what is causing an inflammation.
Limitations
- A gut infection and anti-inflammatory painkillers (NSAIDs) can raise the value without chronic inflammatory bowel disease.
- Blood in the stool, including menstrual blood, can raise the value, because blood contains white blood cells.
- With watery stool the value can be falsely low due to dilution.
- Measurement methods and cut-off values differ between laboratories.
How common is this
Bowel symptoms are common: according to the guideline, irritable bowel syndrome affects about 4 in 100 adults in the Netherlands. Chronic inflammatory bowel diseases such as Crohn's disease and ulcerative colitis are much rarer; the guideline gives no Dutch figure for them. How often an abnormal result for these markers occurs in people without symptoms is not known.
Who is this useful for
In people without symptoms, an abnormal result says little, because the meaning has not been established and a passing infection or a painkiller can raise the value. With long-lasting diarrhea or abdominal symptoms, the GP uses calprotectin in the stool to rule out a chronic inflammation of the bowel, and a blood test if celiac disease is suspected. With blood in the stool, unintended weight loss, diarrhea at night or new bowel symptoms after age 50, this test is no substitute for a visit to the GP.
Sources
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results