An aldolase blood test is a special type of test to look for damage to muscles, liver or the heart. Find out how this test is performed, and what the results mean.
The Aldolase Blood Test
An aldolase blood test is a test used to check for disease involving the muscle, heart or liver. Aldolase is an enzyme involved in the breakdown of sugar into energy, and it comes in three different forms.
Aldolase A is found in greatest amounts in muscle tissue. When muscle tissue is damaged or disease, levels of aldolase A rise in the blood and can be detected by an aldolase blood test. Aldolase B is found in higher quantities in the heart and liver, so it’s most useful for looking for disease in these organs.
How the Test is Used
Doctors check for aldolase A in the bloodstream to monitor the course of certain diseases involving muscle tissue such as muscular dystrophy. When muscle tissue is injured or damaged, aldolase is released into the bloodstream, and levels will be elevated upon blood testing. Measuring aldolase A levels is also helpful in differentiating muscular disease from neurological disease. Neurological diseases such as multiple sclerosis cause muscle weakness that can be hard to distinguish from disease of the muscle, but in neurological disease aldolase A levels will be normal, which helps to differentiate the two types of conditions.
Aldolase B levels will be elevated if the liver or heart is diseased or damaged. For example, a doctor might order an aldolase B level if he suspects a patient has had a heart attack or has liver disease of any type. An elevated aldolase B level can give valuable clues that something is amiss with one of these two organs. This test isn’t as widely used these days since there are other blood markers that are more specific for liver and heart-related damage.
How the Test is Done
Before an aldolase blood test is drawn, it’s important to fast for at least eight hours, and avoid strenuous activity since this can falsely elevate aldolase levels and make the results inaccurate. Certain medications can do the same - so certain ones need to be stopped before the test. To do the test, a small amount of blood is drawn from the arm and sent to the lab for testing.
Understanding the Results
Aldolase levels vary with age. Newborn babies have higher levels than adults, and normal values can vary depending upon the lab that conducts the testing.
Some conditions that elevate aldolase A levels are muscular dystrophy, polymyositis, dermatomyositis, trauma and motor-neuron diseases such as ALS. In many cases, another enzyme called CK will also be elevated. Diseases that cause aldolase B levels to be high are hepatitis, liver tumors, mononucleosis, alcoholic liver disease, heart attack, pancreatitis and trauma – among others.
The Bottom Line
An aldolase blood test provides invaluable information about diseases of the muscle, liver and heart. It's most useful for diagnosing and following muscle diseases since there are better tests to look for liver and heart problems.
Medline Plus. “Aldolase Test"
Am Family Physician. 2005 Apr 1;71(7):1327-1336
Merck Manual. Eighteenth edition. 2006