Synonyms
- A-1 Apolipoprotein
- Alpha-Apolipoprotein
Special Instructions
State patient's sex on the test request form.
Expected Turnaround Time
1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
For more information, please view the literature below.
Specimen Requirements
Specimen
Serum (preferred) or plasma
Volume
2 mL
Container
Red-top tube, gel-barrier tube, green-top (heparin) tube, or lavender-top (EDTA) tube
Collection
Separate serum or plasma from cells. Transfer specimen to a plastic transport tube.
Storage Instructions
Maintain specimen at room temperature.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Patient Preparation
Patient must be fasting 12 to 14 hours.
Causes for Rejection
Specimen from nonfasting patient
Test Details
Use
Apo A-1 comprises 60% to 70% of the protein content of HDL. Apo A-1 serves as an activator of LCAT which is involved in the transport of cholesterol from peripheral tissues to the liver where it is degraded. Decreased serum HDL cholesterol levels have been reported to correlate with increased risk of coronary artery disease (CAD); however, Apo A-1 has been suggested as a better discrimination of CAD than HDL.1 Apo A-1 levels also correlate with survival rates or risk factors for patients with myocardial infarction and peripheral vascular disease. Measurement of Apo A-1 may also aid in the diagnosis of Tangier disease (absence of alpha-lipoprotein).
Methodology
Immunologic
Reference Interval
See table.
Male (mg/dL) | |
|---|---|
0 to 14 d | 62−91 |
15 d to 11 m | 53−175 |
1 to 5 y | 80−164 |
6 to 12 y | 107−175 |
>12 y | 101−178 |
Female (mg/dL) | |
0 to 14 d | 71−97 |
15 d to 11 m | 53−175 |
1 to 5 y | 80−164 |
6 to 80 y | 116−209 |
>80 y | 114−214 |
Footnotes
1. Maciejko JJ, Holmes DR, Kottke BA, et al. Apolipoprotein A-1 as a marker of angiographically assessed coronary-artery disease. N Engl J Med. 1983; 309(7):385-389. 6410239
References
Colantonio DA, Kyriakopoulou L, Chan MK, et al. Closing the gaps in pediatric laboratory reference intervals: A CALIPER database of 40 biochemical markers in a healthy and multiethnic population of children. Clin Chem. 2012 May; 58(5):854-868. 22371482
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 016873 | Apolipoprotein A-1 | 1869-7 | 016873 | Apolipoprotein A-1 | mg/dL | 1869-7 |
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