ALK PHOS ISOENZYME
- ALK PHOS ISOENZYME
- Start Date
- Expiration Date
- Fractionated Alkaline Phosphatase
- CPT Codes
- Reference Test
- ATLAS Test Code
- Transport Info
- Fasting Required?
- Patient Instructions
- Reference Range
Evaluate contribution of liver, bone, and intestinal isoenzymes in relationship to total alkaline phosphatase.
Liver Isoenzymes: There are two liver isoenzymes, L1 and L2. L1 can be increased in some non-malignant diseases (such as cholestasis, cirrhosis, viral hepatitis and in various biliary and hepatic pathologies). It can also be increased in malignancies with hepatic metastasis, in cancer of the
lungs and digestive tract and in lymphoma. The L2, also called macrohepatic or fast liver, also exists in healthy
subjects but at lower concentration than L1. It can be increased in cholestasis and biliary diseases (such as cirhhosis, viral hepatitis) and in malignancies (such as breast, liver, lung, prostate, digestive tract) with liver metastasis.
Bone Isoenzyme: The bone isoenzyme has to be interpreted with respect to age since its elevation is physiologically normal during the growth age. Increase of the fraction may be associated with the following conditions:
- Malignancies with bone metastasis
- Osteosarcoma and lymphoma with or without metastasis
- Rheumatismal diseases, hyperparathyroidism, Paget disease and rachitism
- Transient hyperphosphatasemia in infancy that is associated with a particular liver fraction, total alkaline phosphatase is highly elevated in this case.
- When associated with an increase of other fractions, it may indicate malignancy of rectum, lung and prostate (with bone and liver metastasis)
Intestinal Isoenzymes: Intestinal isoenzymes are often found in individual with blood types O and B. Its increase may be associated with liver cirrhosis, diabetes, and chronic renal failure.
Placental Isoenzymes: Placental isoenzymes are found in pregnancy and begin rising late in first trimester. They continue to rise up to one month after the termination of pregnancy. These enzymes are also associated with some malignant diseases such as ovarian cancer, sarcomas,
pancreatic, and stomach cancers. An increase can also be seen in heavy smokers.