Gut
PMN elastase
An enzyme from white blood cells in the stool; an inflammation marker that has been studied less well than calprotectin.
Everything about this testWhat it measures
PMN elastase is an enzyme from neutrophilic granulocytes, white blood cells that come to the bowel wall during inflammation. It is a different enzyme from pancreatic elastase, which comes from the pancreas. The test measures how much PMN elastase is in a stool sample, as a measure of inflammatory cells in the gut.
- Inflammation of the bowel wall, for example with a gut infection or chronic inflammatory bowel disease (IBD)
High
A raised value points to inflammatory cells in the gut. This may fit a bacterial gut infection, use of anti-inflammatory painkillers (NSAIDs) or 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. Blood in the stool, including menstrual blood, can raise the value. Calprotectin in the stool has been studied better for this question.
Low
For most of these markers, a low value is the usual result. A low value then has no further meaning. It does not rule out a bowel condition; to rule out a chronic inflammation of the bowel, calprotectin in the stool has been studied better.
If your result is abnormal
With an abnormal result without symptoms, no follow-up is usually needed. With bowel symptoms, the GP can request calprotectin in the stool and blood tests, and refer you to a gastroenterologist if there are signs of a chronic inflammation of the bowel.
Reliability
For most markers in this group, it has not been shown what an abnormal value means, in people without symptoms and also not with bowel symptoms. To detect or rule out bowel inflammation, calprotectin in the stool (a separate test) has been studied much better. Some are sometimes used in hospital for a specific question; others are mainly used in scientific research. A "leaky gut" is not a recognized diagnosis, and none of these markers can make such a diagnosis.
Limitations
- Anti-inflammatory painkillers (NSAIDs), a recent intestinal infection, blood in the stool and menstrual blood can raise the value.
- Loose or, on the contrary, hard stool changes the concentration in a stool sample.
- Measurement methods are not standardized; cutoff and reference values differ per laboratory.
- The substances can break down if the stool is in transit for a long time or is stored warm.
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