Lipoprotein(a), Serum
Use
Lipoprotein (a) [Lp(a)] is used to refine cardiovascular disease risk in patients with moderate or high risk based on conventional risk factors or those with clinical suspicion of residual risk not identified by other lipid parameters. Lp(a) is an independent risk factor for coronary heart disease, ischemic stroke, and aortic valve stenosis, with proatherogenic and prothrombotic properties due to its structure, including apolipoprotein B100 and similarity to plasminogen. The heterogeneity of Lp(a) size can complicate accurate immunochemical measurement.
Special Instructions
The test requires specific collection and submission protocols: use a serum gel or red top collection container, and transfer serum into a plastic vial after centrifugation. Complete appropriate forms if not ordering electronically.
Limitations
The immunoassay for Lp(a) faces challenges due to Lp(a) molecular size heterogeneity, complicated by polymorphisms in the Apo(a) protein with size ranging from 240 to 800 kDa. Such variability affects the assay accuracy, although calibrating to molar units helps minimize inaccuracies. Factors like diet and lifestyle mainly do not affect Lp(a) levels; however, the degree of atherogenicity may depend on the specific molecular size of Lp(a). Additionally, certain population groups exhibit different baseline Lp(a) concentrations, and conditions like gammopathy may interfere with results.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Immunoturbidimetric Assay)
Biomarkers
LOINC Codes
- 43583-4
- 43583-4
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into plastic vial.
Causes for Rejection
Gross hemolysis, Gross lipemia, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 7 days |
| Frozen | 30 days |