Apolipoproteins (Apo-A1 and Apo B)
Chemical Pathology
Notes
- Apolipoproteins are the major protein component of lipoproteins (whose function is to transport lipids), and are important in maintaining the structural integrity and solubility of lipoproteins; in lipoprotein receptor recognition and in the regulation of certain enzymes in lipoprotein metabolism.
- Apolipoprotein A-1 (Apo A-1) and apolipoprotein B (Apo B) are used alongside other routine lipid tests to help determine an individual’s risk of developing CVD - not as a general population screen but rather where patients have a family history of heart disease &/or hyperlipidaemia to help determine the cause (especially in situations in which the LDL-cholesterol cannot be calculated).
- Apo B concentrations may also be used to monitor the effectiveness of lipid treatment as an alternative to non-HDL-C (non-HDL-C is the total cholesterol concentration minus the amount of HDL-cholesterol).
- In rare cases, an Apo B test may be requested to help diagnose a genetic problem that causes over- or under-production of Apo B.
- Apo A-I levels may be used to help diagnose rare conditions that cause Apo A-I deficiencies, such as Tangier and fish eye disease.
- Although occasionally requested by some specialist doctors, apolipoproteins are not routinely used tests and are currently not recommended for widespread testing.
Please note: Apolipoprotein requests are available to the GHNHSFT lipid clinic consultants only - any queries should be referred to them.
Sample requirements
For adults, 5 ml of blood taken into a narrow plain gold top gel tube.
Storage/transport
Do not store. Send to the laboratory at room temperature on the day of venepuncture. Samples must be centrifuged and serum separated from red cells in less than 12 hours.
Required information
Relevant clinical details including the reason for the request, fasting state, any family history, current lipid medication and date and time of sample.
Turnaround times
Samples are sent to a referral laboratory for analysis with results normally available within 4 weeks.
Reference ranges
| Age | Apolipoprotein A-1 (g/L). Female | Apolipoprotein A-1 (g/L). Male |
|---|---|---|
| <14 days | 0.71 - 0.97 | 0.62 - 0.91 |
| 15 days - 1 year | 0.53 - 1.75 | 0.53 - 1.75 |
| 1y - 14y | 0.80 - 1.64 | 0.80 - 1.64 |
| 14y - 19y | 0.72 - 1.54 | 0.72 - 1.54 |
| 19y - 60y | 1.01 - 2.23 | 0.95 - 1.86 |
| >60y | 0.91 - 2.24 | 0.73 - 1.86 |
| Age | Apolipoprotein B (g/L) |
|---|---|
| <14 days | <0.68 |
| 15 days - 1 year | <1.24 |
| 1y - 6y | <0.94 |
| 6y - 19y | <0.85 |
| >19y | 0.4 - 1.20 |
NB: different ApoB concentration targets may be used by specialists in treating people at high cardiovascular risk.
Further information
https://patient.info/doctor/apolipoproteins
Page last updated 31/07/2019