Evaluating risk for atherosclerotic cardiovascular disease
Aiding in the detection of Tangier disease
Automated Turbidimetric Immunoassay
Apo A
Apo A-1
Apo A1
Apo B
ApoA
ApoA-1
ApoA1
ApoB
Apolipoprotein A
Apolipoprotein A-I
Apolipoprotein A1
Apolipoprotein A1+B ORDER APABR
Apolipoprotein AI
Serum
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Collection Instructions:
1. Centrifuge and aliquot within 2 hours of collection.
2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.
If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.
0.5 mL
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 8 days | |
Frozen | 60 days | ||
Ambient | 24 hours |
Evaluating risk for atherosclerotic cardiovascular disease
Aiding in the detection of Tangier disease
Apolipoprotein A1 (ApoA1) is the primary protein associated with high-density lipoprotein (HDL) particles, and plays a central role in reverse cholesterol transport.(1) HDL cholesterol (HDL-C) and ApoA1 concentrations are inversely related to the risk for coronary artery disease (CAD).(2) There are a variable number of ApoA1 proteins per HDL particle. Therefore, ApoA1 is not a 1:1 surrogate marker for HDL particles. Similarly, the number of ApoA1 proteins and the amount of cholesterol contained in HDL particles is highly variable. This heterogeneity has led to unique clinical findings related to ApoA1 compared with HDL-C.
Increased ApoA1 concentrations are more strongly associated with a reduction in risk of a first myocardial infarction than HDL-C concentrations.(3) Low concentrations of ApoA1, but not HDL-C, are predictive of preclinical atherosclerosis as assed by computed tomography estimated coronary artery calcium (CAC) scoring.(4) Increased ApoA1, but not HDL-C concentrations, are associated with reduced cardiovascular events among statin-treated patients, even when LDL-C <50 mg/dL.(5) In statin-treated patients, patients whose ApoA1 increased while on treatment were at lower risk than those whose ApoA1 did not increase.
Males
Age | Apolipoprotein A (mg/dL) |
<24 months | Not established |
2-17 years | Low: <115 Borderline low: 115-120 Acceptable: >120 |
>18 years | > or =120 |
Females
Age | Apolipoprotein A (mg/dL) |
<24 months | Not established |
2-17 years | Low: <115 Borderline low: 115-120 Acceptable: >120 |
>18 years | > or =140 |
Low levels of apolipoprotein A1 (ApoA1) confer increased risk of atherosclerotic cardiovascular disease.
ApoA1 below 25 mg/dL may aid in the detection of a genetic disorder such as Tangier disease.
ApoA1 is often interpreted as a ratio with apolipoprotein B (ApoB).
1. Sorci-Thomas MG, Thomas MJ: Why Targeting HDL Should Work as a Therapeutic Tool, but Has Not. J Cardiovasc. Pharmacol 2013;62:239-246
2. Di Angelantonio E, Sarwar N, Perry P, et al: Emerging Risk Factors Collaboration. Major lipids, apolipoproteins, and risk of vascular disease. JAMA 2009;302:1993-2000
3. McQueen MJ, Hawken S, Wang X, et al: Lipids, lipoproteins, and apolipoproteins as risk markers of myocardial infarction in 52 countries (the INTERHEART study): a case control study. Lancet 2008;372:224-233
4. Sung KC, Wild SH, Byrne CD: Controlling for apolipoprotein A-I concentrations changes the inverse direction of the relationship between high HDL-C concentration and a measure of pre-clinical atherosclerosis. Atherosclerosis 2013;231:181-186
5. Boekholdt SM, Arsenault BJ, Hovingh GK, et.al: Levels and Changes of HDL Cholesterol and Apolipoprotein A-I in Relation to Risk of Cardiovascular Events Among Statin-Treated Patients: A Meta-Analysis. Circulation 2013;128:1504-1512
Antiapolipoprotein A-1 antibodies react with the antigen in the sample to form antigen/antibody complexes which, following agglutination, can be measured turbidimetrically.(Package Insert: Tina-quant Apolipoprotein A-1, Roche Diagnostics. Indianapolis, IN. 05/2017)
Monday through Sunday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
82172
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
APOA1 | Apolipoprotein A1, S | 1869-7 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
APOA1 | Apolipoprotein A1, S | 1869-7 |