| Laboratory: | Clinical Biochemistry (SENDOUTS) |
| Test Name: |
ALKALINE PHOSPHATASE (ALP) ISOENZYMES - (S)
Test Code:
APIE
|
| Clinical Information: |
Description:
- Significant isolated elevation of total ALP (>2x ULN) is usually due to bone pathology rather than hepatic/biliary pathology - Minor isolated elevation of total ALP (<1.5x ULN) is very common and may be repeated in 3 months to look for increase. - Mild and stably elevated ALP up to 1.5x ULN is often seen in the elderly. This may be of bony or hepatic origin but does not require further investigation in the absence of relevant clinical findings - An elevated bone alkaline phosphatase can occur in vitamin D deficiency, Paget’s disease (increasing in incidence from age 55 onward and significant in those over 75 years of age), osteogenic sarcoma, bone metastasis, healing fractures, hyperparathyroidism, hyperthyroidism, and osteomalacia - Elevated intestinal fraction tends to occur after a fatty meal and runs in families. - Marked isolated elevation (>4x ULN) of liver ALP may occur due to drug and toxin cholestasis, PBC, PSC or metastatic carcinoma to the liver - Elevated levels of ALP during pregnancy (2-4x ULN) are due to increased placental enzyme. Test Indications: ALP isoenzymes analysis is rarely useful and is not recommended for routine investigation. If deemed necessary as a part of investigation of isolated raised ALP (>2x ULN) in vitamin D replete patient, assay allows differentiation between liver, bone, and intestinal isoenzymes. Test Approval Requirements: Clinical Biochemist Approval Required |
| Collection Devices: |
Preferred Device:
|
| Specimen Required: |
Serum: 3.0 mL
3.0 mL preferred Specimen Stability: Refrigerated: 7 days Frozen: 1 month at -20 C |
| Referral: |
Serum: 1.0 mL
Shipping & Storage: Aliquot, store and send frozen to HSC clinical Chemistry – MS5.
Testing Laboratory(MB): Referred Out Referred Out Location: Specimen referred from HSC-MS5 to: In-Common Laboratories 57 Gervais Drive North York, Ontario M3C 1Z2 Telephone: (416) 422-3000 Test ID: ALPISO Testing location: LRC, Hamilton, ON |
| Requisition: | |
| Reference Values: |
Reference Intervals:
20 years and over: Total liver: 32-87 U/L Bone: 14-53 U/L Intestinal 1,2,3: 1-13 U/L Method of Analysis: Sebia gel electrophoresis |
| Availability: |
Within 3 Weeks
Clinical Biochemist Approval Required
|
| See Also: | |
| More Information: |
Interpretation & Assay Interferences: Do not use hemolyzed samples as red cell enzymes may interfere with reaction. Anticoagulants, such as EDTA, citrate and oxalate inhibit ALP activity.
References: Bader, Andrew DO; Westfall, Erin DO What is the workup of an isolated elevation of alkaline phosphatase?, Evidence-Based Practice: April 2018 - Volume 21 - Issue 4 - p 6 Shipman K E, Holt A D, Gama R. Interpreting an isolated raised serum alkaline phosphatase level in an asymptomatic patient BMJ 2013; 346 :f976 Kwo PY, Cohen SM, Lim JK. ACG Clinical Guideline: evaluation of abnormal liver chemistries. American Journal of Gastroenterology 2017;112:18-35. Abnormal Liver Chemistry – Evaluation and Interpretation. Guidelines and Protocols Advisory Committee, British Columbia, Canada, 2011. www.BCGuidelines.ca The abnormal liver chemistry profile – National Laboratory Handbook by National Clinical Program for Pathology, 2018. Newsome PN, Cramb R, Davison SM, et al Guidelines on the management of abnormal liver blood tests. Gut 2018;67:6-19 |