Cholinesterase (CHE) is an enzyme belonging to group III of the EC classification (hydrolases), which catalyzes the hydrolytic cleavage of the ester bond between the OH group of choline and the carboxy group of an organic acid. It is synthesized in the liver. In liver disease, the decrease in cholinesterase indicates that the synthesis power (power to make new) of the liver is limited. The following two forms of cholinesterase can be distinguished:
- Acetylcholinesterase (true cholinesterase).
- Pseudocholinesterase (nonspecific cholinesterase; butyrylcholinesterase, BCHE); enzyme that catalyzes hydrolytic cleavage of the ester bond in choline esters); is also capable of cleaving various esters that contain an alcohol component other than choline, for example, aspirin, cocaine, and heroin
The process
Material needed
- Blood serum or plasma (EDTA, heparin); to avoid hemolysis (dissolution of red blood cells), the serum or plasma should be centrifuged if the sample is transported for a long time
Preparation of the patient
Interfering factors
- Not known
Normal values – blood serum
| Age reference range (25 °C) in U/l | New reference range (37 °C) in U/l | New reference range (37 °C) in kU/l | |
| Children (2.-15. LJ) | 3.500 – 8.400 | 4.620 – 11.350 | 4,6 – 11,4 |
| Women (16.-39.LJ) | 2.800 – 7.400 | 3.930 – 10.300 | 3,9 – 10,3 |
| Women (> 39 y.) | 3.500 – 8.500 | 4.620 – 11.500 | 4,6 -11,5 |
| Men | 3.500 – 8.500 | 4.620 – 11.500 | 4,6 -11,5 |
Indications
- Diagnosis/evaluation of hepatocellular function (synthesis performance of the liver):
- Severe hepatocellular damage (e.g., liver cirrhosis).
- Chronic hepatitis
- Before administration of muscle relaxants (suxamethonium; drugs used to relax skeletal muscles) if CHE variant is suspected.
- Prolonged apnea (respiratory arrest) and immobility after anesthesia.
- Intoxication (poisoning) with pesticides.
Interpretation
Interpretation of increased values
- Diabetes mellitus (diabetes).
- Exudative enteropathy (protein loss enteropathy) – gastrointestinal disease in which there are large protein losses.
- Familial cholinesterase variants.
- Hyperlipoproteinemia type IV (lipid metabolism disorder).
- Coronary artery disease (CAD) – disease in which there is a lack of oxygen supply to the heart muscle due to stenosis (narrowing) of the coronary arteries (arteries that surround the heart in a wreath shape and supply the heart muscle with blood).
- Nephrotic syndrome – collective term for symptoms that occur in various diseases of the glomerulus (renal corpuscles); proteinuria (excretion of protein with urine) with a protein loss of more than 1 g/m² KOF/d; hypoproteinemia, peripheral edema (water retention) due to hypalbuminemia of < 2.5 g/dl in serum; hyperlipoproteinemia (lipid metabolism disorder).
- Steatosis hepatis (fatty liver).
Interpretation of lowered values
- Genetic variants
- Neoplasms of the liver, unspecified
- Malnutrition/malnutrition and hypalbuminemia (decreased concentration of the plasma protein albumin in blood plasma.).
- Poisoning with organophosphates E605, E600.
- Decreased synthesis capacity of the liver:
- Chronic hepatitis (inflammation of the liver).
- Chronic liver congestion
- Cirrhosis of the liver – irreversible (non-reversible) damage to the liver and a marked remodeling of liver tissue.
Further notes
- For atypical cholinesterase variants, dibucaine number is measured (activity before and after dibucaine addition); normal value: > 65%.
- Due to its long half-life of 12-14 days, cholinesterase activity is often within the normal range in acute liver disease!
- Cholinesterase is considered a prognostic factor in fulminant liver failure, liver cirrhosis and after liver transplantation.
- Other parameters used to monitor liver synthesis performance include serum albumin, cholesterol, and Quick value/IRN.
- If a genetic defect is suspected, genetic analysis can be performed.
