Aldolase Test

Aldolase is mainly a muscle enzyme present in three different isomeric forms: aldolase A, B and C. While aldolase A is found in muscle cells, B and C are found in brain, liver and other organs. Aldolase is responsible for maintaining the muscles cell shape, mobility of muscles, actin filament organisation and adenosine triphosphate (ATP) biosynthesis. 

Serum aldolase A can be used as a biomarker in malignancies of the lungs and kidneys to predict the presence of these conditions. It can also be used for the early detection of colorectal cancer. Infectious diseases causing gangrene and autoimmune conditions, such as polymyositis, are also characterised by elevated levels of aldolase. Rhabdomyolysis, a skeletal muscle injury syndrome, is a life-threatening condition in which increased levels of aldolase are seen in the blood. It is advisable to monitor serum aldolase concentration in such individuals to ensure appropriate treatment. An aldolase test is advised in the following conditions either as the main or an ancillary test:

• Muscle weakness
• Muscle pain and cramps
• Pancreatitis
• Hepatomegaly in infants
• Neonatal liver disease
• Cancer of the colon, rectum or liver
• Rashes and papules on skin with muscular weakness
• Burns
• Myocardial infarction 
• Dermatomyositis, which is an inflammatory condition with papule and rash 
• Haemolytic anaemia in malaria due to Plasmodium falciparum, which is rare but life-threatening 

It is a simple procedure that does not require special preparations. The patient may be sometimes asked to do short fasting (up to 6 hours) for accurate results. It is advisable to inform your doctor and pathologist about the current medication to ensure that those drugs that interfere with test results may be stopped before the test. 

A skilled laboratory technician will withdraw around 5 millilitres of blood from a vein of your forearm with the help of a needle and store the sample in a sterile tube. The sample is then sent for analysis. Some patients may feel a stinging sensation when the blood is collected. After sample collection, the technician will apply an antiseptic at the site to prevent infection.

Normal results: Normal values of aldolase concentration in serum are 0-7 international units (IU)/litre (L) for adults. In children, the concentration is twice that of adults, while in newborns, it is four times the concentration in adults.

Abnormal results: Increased or decreased concentrations of serum aldolase indicate abnormal values. Increased serum concentrations of aldolase in patients suffering from myopathy suggest a possibility of developing systemic sclerosis. Such patients need regular monitoring of aldolase along with other laboratory investigations. In patients with heart conditions, chronic hypoxia leads to apoptosis of the cardiac myocyte (heart muscle cells); however, anaerobic glycolysis protects the myocardium (heart muscles), and aldolase plays a key role in this process. Increased serum concentrations of aldolase may suggest the presence of the following conditions:

• Muscle trauma and skeletal muscle injury 
• Muscle inflammation or necrosis
• Myocardial infarction
• Acute hepatitis
• Colorectal cancer
• Dermatomyositis
• Gangrene
• Burns
• Pancreatitis

Decreased levels of aldolase in the serum indicate the presence of the following conditions:

• Late muscular dystrophy
• Haemolytic anaemia, which is a rare condition
• Hereditary fructose intolerance, which is evident in infants only during the introduction of new food products containing fructose

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational perspective and is in no way a substitute for medical advice from a qualified doctor.