Alkaline Phosphatase Isoenzymes

Alkaline Phosphatase Isoenzyme blood test is a test used to measure the amount of different types of ALP in the blood. This test helps in diagnosing and monitoring of bone diseases (Paget’s disease, Osteoporosis, Osteopenia, Osteomalacia, Osteolytic lesions), liver gall bladder or bile duct disease, parathyroid gland disease, vitamin D deficiency.

Paget’s Disease: Paget’s Disease is a bone disorder in which old bone tissues are gradually replaced by new bone tissues. This may lead to fragile bones.

Osteoporosis: This is a type of bone disease where the bones become weak and brittle. This condition is due to an imbalance between the breakdown and rebuilding of bone tissues. This is mostly disturbed due to hormonal changes or dietary changes. During these changes, the bone may lose some of the minerals that contribute to its density and strength.

Osteopenia: This is a condition in which the bone density is decreased.

Osteomalacia: Osteomalacia is caused due to deficiency of vitamin D and calcium which results in softening of bones.

Osteolytic lesions: Osteolytic lesions are the symptoms of specific diseases like breast cancer, multiple myelomas, etc. Osteolytic lesions are the softened section of the bones.

What is Alkaline Phosphatase (ALP)?

Alkaline Phosphatase is an enzyme found in various tissues throughout the body like liver, gall bladder, bone, bile ducts, intestine, etc. It is found in many variations called isoenzymes. Each isoenzyme of ALP is different, depending on where it’s made in your body. The highest concentrations of alkaline phosphatase are found in bone and liver. ALP-2 isoenzyme is made by bones. The levels of this enzyme increase when your bones are growing or bone cells are active.

Why this test is performed?

This test may be recommended to you to check your bone health. This test is also recommended if you experience certain symptoms like pain in the abdomen, chronic bone pain, joint pain, deformed bones, bones that are brittle or break easily. If you had a fracture recently this test may be performed to assess the strength of your bones. This test is also recommended to evaluate the effectiveness of the treatment given for any of your bone diseases.

Precautions:

Ceratin drugs like aspirin, antibiotics, estrogen, and birth control pills may affect the levels of alkaline phosphatase. Hence inform your doctor or technician about all your current medications and medical conditions prior to the test

The alkaline phosphatase isoenzyme test results can detect whether the increase is in bone ALp or liver ALP. The normal test results may vary depending on age, health history, medical condition, etc.

If your alkaline phosphatase isoenzyme test results are higher than the normal reference range, it may indicate bone diseases such as osteomalacia, osteoporosis, osteoblastic bone tumors, Paget's disease, etc or biliary obstruction, hepatitis, leukemia, liver disease, lymphoma, rickets, sarcoidosis, etc.

If your alkaline phosphatase isoenzyme test results are lower than the normal reference range, it may indicate Wilson disease, hypophosphatasia, protein deficiency, malnutrition, etc.