Enzymes are a type of highly specialized complex proteins produced naturally within each cell and a vital part of the healthy functioning of the overall body. While some enzymes help by creating chemical reactions within the body, others actually speed up the rate of a chemical reaction to help support life. Some important functions of enzymes include building muscle, breaking down food particles during digestion, helping in blood coagulation and destroying toxins. Quite often inactivity of an enzyme diminishes the bodily functions or leads to some other health issue. Since, enzymes are crucial for good health, hence it is extremely important to know whether they are present and functioning properly. And doctors often suggest for a test to determine this, which is known as Enzyme Marker Test.

Also Read: Blood Typing Test: What Is It And What To Expect?
Cardiac Marker Test

What Is Enzyme Marker Test?

Enzyme Marker Test, also known as Enzyme analysis, is a blood test to measure the activity of specific enzymes in a sample of blood serum, usually for the purpose of identifying an inherited disease or abnormal condition that can cause these enzymes to stop working or be less efficient.

What Are The Common Types Of Enzymes?

Although the human blood serum contains more than 50 types of enzymes, the most common ones include:

Amylase: A starch-digesting enzyme that chiefly originates from the pancreas and salivary glands.

Lipase: A fat-digesting enzyme that also gets secreted in the pancreas.

Alkaline phosphatase: An enzyme found in most body tissues, but especially in the bones and liver.

Acid Phosphatase: An enzyme also found in most body tissues but in unusually greater concentration in the adult prostate gland.

Peptidases: A group of enzyme-digesting proteins that are found in greater concentrations in the blood serum.

Transaminases: This includes glutamic-aspartic transaminase and glutamic-alanine transaminase, enzymes that are found in most body tissues, but in particularly elevated levels in the liver and heart tissue.

What Are The Common Types Of Enzyme Markers And Its Significance?

CPK Isoenzymes

CPK enzymes are generally present in the heart, brain, and skeletal muscles and the test mainly measures the creatine phosphokinase (CPK) in the blood serum.

Normal range of CPK levels in the blood should be 200 units per liter (U/L) or less.

There are usually 3 types of CPK enzymes, and variations from normal levels include:

CPK-1 resides mostly in the brain and lungs and an increase in its concentration can be due to:

  • Brain cancer
  • Seizure
  • Brain injury, stroke, or bleeding in the brain
  • Pulmonary infarction
  • Electroconvulsive therapy

CPK-2 levels chiefly rise following a heart attack and elevated levels of CPK-2 may be due to:

  • Inflammation of the heart muscle
  • Heart injury
  • Open heart surgery
  • Chest compressions after cardiac arrest
  • Defibrillation
  • Electrical injuries

Higher concentration of CPK-3 levels can be due to:

  • Muscle damage, dystrophy, or inflammation
  • Seizures
  • Strenuous exercise
  • Intramuscular injections
  • Electromyography
  • Recent surgery

Heart Enzymes

Some heart enzymes slowly enter the blood just after  a heart attack causing damage of the heart. Doctors usually conduct a general test for emergency room patients with heart attack symptoms to look for the presence of certain proteins in the blood. This test is known as CPK-2, or CK-MB marker test. This marker rises rapidly after a heart attack and is highly specific for heart muscle injury.

The normal CK-MB levels in the blood should be between 5-25 international units per liter (UI/L).

Liver enzymes

There are many markers that can be used to test the liver function which chiefly help to identify whether or not there is any injury to the liver parenchyma (i.e., liver cells) or to the biliary system. The main tests for determining liver functions are the liver aminotransferases which include Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST). Elevated liver enzymes may be due to inflammation or damaged liver cells.

But elevated liver enzymes can be due to:

  • Prescription and/or over-the-counter (OTC) medications
  • Alcohol consumption
  • Heart failure or heart attack
  • Liver disease, such as hepatitis, fatty liver disease, cancer, and cirrhosis
  • Hemochromatosis
  • Underactive thyroid
  • Obesity
  • Celiac disease
  • Inflammatory diseases, such as pancreatitis, and gallbladder inflammation and dermatomyositis,
  • Muscular diseases, such as muscular dystrophy or polymyositis
  • Viruses, such as cytomegalovirus infection such as hepatitis A, B, C, E viruses; mononucleosis; and Epstein-Barr virus
  • Ischemia
  • Wilson disease
  • Physical trauma to the organ

A normal ALT level mainly ranges from 29-33 IU/L for men, and 19-25 IU/L for women, whereas a normal AST level may range from 10-40 IU/L for men and 9-32 IU/L for women.

Also Read: Can an Enzyme Treat Celiac Disease?

How Is The Test Conducted?

Enzyme marker test is a routine blood test and require no fasting or special preparations. But do tell the doctor before the test about all prescription and OTC medications and supplements you take.

Are There Any Side Effects Of The Test?

There are usually no reported side effects from taking an enzyme marker test apart from slight pain and bruising at the puncture site that too only for some time after which it usually subsides on application of an ice pack or on its own. In very rare case scenarios, there were reports of infection at the puncture site, excessive bleeding, or dizziness.


A test result outside the given normal range mainly indicates a variety of problems from disease to a simple muscle strain because enzymes are produced in every cell of the body. Based on the results, the doctor will suggest for a proper course of treatment for the underlying condition.