Blood draw
Cholinesterase
Cholinesterase activity; liver function or organophosphate exposure.
€ 35,00
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Liver and pancreas · Blood
Cholinesterase
An enzyme from the liver; shows how sensitive someone is to certain muscle relaxants and says something about the liver.
At a glance
- Measured in blood
- In 2 test panels
- No special preparation
Explanation
Cholinesterase: what is measured?
The test measures the activity of pseudocholinesterase (butyrylcholinesterase), an enzyme that the liver makes and releases into the blood. The enzyme breaks down certain substances, including the muscle relaxant succinylcholine that is used during general anesthesia. Because the liver makes the enzyme, its activity is also a measure of how much protein the liver can produce. In addition, some insecticides (organophosphates) inhibit the enzyme.
What can it detect?
- An inherited reduced activity of the enzyme, which makes certain muscle relaxants work longer during general anesthesia
- A reduced production function of the liver
- Poisoning with organophosphate insecticides
Result
What does the result mean?
Cholinesterase too high
A raised activity occurs with overweight, fatty liver, a raised fat level in the blood, diabetes and with protein loss through the kidneys. A raised value causes no symptoms itself and usually has little meaning.
Cholinesterase too low
According to the Dutch Society for Clinical Chemistry (NVKC), a low activity usually has an inherited cause: an abnormality in the structure of the enzyme. People who have this notice nothing in daily life, but can remain paralyzed much longer than expected after general anesthesia with succinylcholine. A low value can also fit severely reduced liver function, malnutrition, a serious illness or poisoning with organophosphate insecticides. Pregnancy, the contraceptive pill and some medicines slightly lower the value without there being a disease.
After an abnormal result
With a clearly low value, it is especially important that the anesthesiologist knows this before any surgery; sometimes further testing for the inherited variant follows, and family members may then also have increased sensitivity. With a low value together with other abnormal liver results, the GP looks at the cause of the liver function disorder.
Reliability
How reliable is the test?
A clearly low activity reliably points to increased sensitivity to succinylcholine; which inherited variant is behind it only becomes clear from further testing with inhibitors or DNA. As a measure of liver function, cholinesterase is less specific than albumin and the clotting time (PT or INR), because diet, pregnancy and medicines also lower the value. In people without symptoms, a slightly abnormal value says little.
What can affect the result?
- Pregnancy, the contraceptive pill and other estrogens lower the activity without disease.
- Some medicines, such as certain cancer drugs, cyclophosphamide and neostigmine, lower the activity.
- Overweight, fatty liver and a high fat level in the blood raise the value.
- Reference values and the measurement method differ between laboratories; results from different laboratories are not easy to compare.
Who it is for
Who is the test useful for?
Useful for
The result is mainly meaningful before general anesthesia in someone who themselves, or a family member, previously remained paralyzed for an unusually long time after surgery, when poisoning with insecticides is suspected and as an addition with known liver disease. In people without symptoms, a slightly abnormal value says little.
How common is it?
An inherited reduced activity of the enzyme is not rare: about 1 in 25 to 30 people of European descent carry one abnormal variant, which at most slightly lowers the activity. A severe form, in which both genes are affected, occurs in about 1 in 3,000 to 5,000 people.
Estimate from the medical literature; no Dutch registration figure available
Drawbacks and risks
- A slightly low value due to pregnancy, the pill or medicines can wrongly be read as a liver problem or inherited abnormality.
Evidence
Sources
This explanation is based on Dutch guidelines and independent information. It is general information, not a diagnosis. Discuss an abnormal result with your GP.
More about risks and resultsMore explanations
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