Alkaline Phosphatase Isoenzymes (Sendout)

Useful For:

• Aid in the diagnosis and treatment of liver, bone, intestinal, and parathyroid diseases
• Determining the tissue source of increased alkaline phosphatase (ALP) activity in serum
• Differentiating between liver and bone sources of elevated ALP

Patient Preparation: Fasting (8 hours) required.

Total Alkaline Phosphatase: Colorimetric

Alkaline phosphatase Isoenzymes: Electrophoresis

Reference Values:

Alkaline Phosphatase:

Males:

Females:

Alkaline Phosphatase Isoenzymes:

Age: < or =17 years: Reference values have not been established for patients less than 18 years of age.

Age > or =18 years:

Interpretation:

Liver alkaline phosphatase (ALP) isoenzyme is most frequently elevated when total ALP is elevated. Increased liver ALP is associated with a wide group of conditions including acute hepatitis, cirrhosis, fatty liver, drug induced liver disease, obstruction of biliary flow, bile duct stricture, primary biliary cirrhosis, and metastatic carcinoma of the liver.

Bone ALP is elevated due to increased osteoblastic activity. Abnormally elevated bone ALP may be indicative of bone tumors, Paget’s disease, or renal rickets.

Intestinal ALP is detectable in approximately 20% of samples tested. Intestinal ALP is most frequently noted postprandially in patients with blood group O or B.

Alkaline phosphatase (ALP) Isoenzyme:

• High concentrations of phosphate, oxalate, citrate, and cyanide will inhibit ALP activity.
• Excess glycine may inhibit ALP activity by complexing magnesium.
• Patients should be fasting. Patients may have an elevated intestinal ALP about two hours after a fatty meal.

6 mL blood in GOLD SST or RED TOP tube

Patient Preparation: Patient should be fasting for 8 hours.

Outside Laboratories:

• Centrifuge sample within two hours of collection and aliquot serum into a separate plastic vial.
• Serum from red tops should be immediately aliquoted; serum from gold top tubes may remain on the gel, refrigerated, for up to 7 days prior to being transferred.
• Once transferred, freeze serum at -20°C while awaiting shipment. Transport on dry ice.

Stability: Frozen (Preferred): 14 days; Refrigerated: 7 days; Ambient: 7 days.

Reject Due To: Gross hemolysis or icterus. Gross lipemia is acceptable.

• Centrifuge sample within two hours of collection.
  • Serum from red tops should be immediately aliquoted; serum from gold top tubes may remain on the gel, refrigerated, for up to 7 days prior to being transferred.
• Aliquot serum into a separate plastic vial, leaving room for expansion at the top, and freeze at -20°C.

Sendouts:

• Order Mayo Test: ALKP
• Interfaced: Yes [Interface: 601; Worksheet: MAFZ]

Stability: Frozen (Preferred): 14 days; Refrigerated: 7 days; Ambient: 7 days.

Reject Due To: Gross hemolysis or icterus. Gross lipemia is acceptable.