Alkaline phosphatase (ALP) is an enzyme found in many body tissues such as liver, bile ducts, bone, and intestine. There are several different structural forms of ALP called isoenzymes. The structure of the enzyme depends on where in the body it is produced. This test is most often used to test ALP made in the tissues of the liver and bones.
The ALP isoenzyme test is a lab test that measures the amounts of different types of ALP in the blood.
The ALP test is a related test.
How the Test is Performed
A blood sample is needed. Most of the time blood is drawn from a vein located on the inside of the elbow or the back of the hand.
How to Prepare for the Test
Many medicines can interfere with blood test results.
- Your provider will tell you if you need to stop taking any medicines before you have this test.
- DO NOT stop or change your medicines without talking to your provider first.
How the Test will Feel
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
Why the Test is Performe
This test may be used to diagnose or monitor:
- Bone disease
- Liver, gallbladder, or bile duct disease
- Pain in the abdomen
- Parathyroid gland disease
- Vitamin D deficiency
It may also be done to check liver function and to see how medicines you take may affect your liver.
Normal Results
The normal value for total ALP is 44 to 147 international units per liter (IU/L) or 0.73 to 2.45 microkatal per liter (µkat/L).
this normal range is vary according to age and sex .
Adults have lower levels of ALP than children. Bones that are still growing produce higher levels of ALP.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
The example above shows the common measurement range for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
Higher-than-normal ALP levels:
- Biliary obstruction
- Bone disease
- Eating a fatty meal if you have blood type O or B
- Healing fracture
- Hepatitis
- Hyperparathyroidism
- Hyperthyroidism
- Leukemia
- Liver disease
- Lymphoma
- Osteoblastic bone tumors
- Osteomalacia
- Paget disease of bone
- Sarcoidosis
Lower-than-normal levels of ALP:
- Hypophosphatasia
- Hypothyroidism
- Malnutrition
- Pernicious anemia
- Protein deficiency
- Wilson disease
- Zinc deficiency