Alkaline Phosphatase (ALP)
CPT Code(s):
84075
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.
Rejection Criteria:
Citrate, Fluoride,Sodium Heparin, or EDTA plasma specimen; gross hemolysis; lipemia; improper labeling
Stability Criteria
Room Temperature:
8 hours
Refrigerated:
7 days
Frozen:
30 days
Clinical Significance
Alkaline Phosphatase holds specific clinical significance and diagnostic use in the field of clinical chemistry and medical evaluation. This test measures the level of alkaline phosphatase, an enzyme found in various tissues throughout the body, in a patient's blood.
The clinical significance and diagnostic use of Alkaline Phosphatase include:
1. Assessment of Liver Function: Alkaline phosphatase is predominantly produced in the liver, and elevated levels of this enzyme in the blood can indicate liver dysfunction or damage. ALP helps in assessing liver function, aiding in the diagnosis and monitoring of liver diseases, such as hepatitis, cirrhosis, or biliary obstruction.
2. Detection of Biliary Tract Disorders: Elevated levels of alkaline phosphatase can be specifically indicative of disorders affecting the biliary tract, such as gallstones, cholangitis, or biliary obstruction. ALP helps identify these conditions and can provide information on the severity and progression of the disease.
3. Evaluation of Bone Disorders: Alkaline phosphatase is also produced by bone cells, particularly during periods of active bone growth or remodeling. Abnormal levels of alkaline phosphatase can indicate bone disorders such as Paget's disease, bone metastasis, or certain bone tumors. ALP assists in diagnosing and monitoring these bone-related conditions.
4. Monitoring of Treatment: ALP can be useful in monitoring the response to treatment in liver and bone disorders. A decrease in alkaline phosphatase levels may indicate a positive response to therapy, while persistent or increasing levels may suggest treatment resistance or disease progression.
5. Differential Diagnosis: Abnormal levels of alkaline phosphatase can also help in the differential diagnosis of certain conditions. For example, in the context of liver disease, the pattern of ALP elevation, along with other liver function tests, can aid in distinguishing between hepatocellular and cholestatic liver diseases.
6. Screening for Metastatic Bone Disease: Elevated alkaline phosphatase levels can be an early sign of metastatic bone disease in patients with certain types of cancer. Regular monitoring of alkaline phosphatase levels can aid in the early detection of bone metastasis, guiding further investigations and treatment decisions.
In summary, Alkaline Phosphatase has specific clinical significance and diagnostic uses in assessing liver function, detecting biliary tract disorders, evaluating bone disorders, monitoring treatment response, facilitating differential diagnosis, and screening for metastatic bone disease. By measuring alkaline phosphatase levels, healthcare providers gain valuable insights into liver and bone health, aiding in the diagnosis, monitoring, and management of various medical conditions.