Apolipoprotein A-1
| Apolipoprotein A-1 | | | |
| Number | | 016873 |
| CPT | | 82172 |
| Synonyms | | A-1 Apolipoprotein ; Alpha Apolipoprotein ; Apo A-1 |
| Special Instructions | | State patient's sex on the request form. |
| Specimen | | Serum |
| Volume | | 2 mL |
| Container | | Red-top tube or gel-barrier tube |
| Collection | | Separate serum from cells. Transfer specimen to a plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. |
| Storage Instructions | | Refrigerate at 2°C to 8°C. Stable for up to 3 days. Freeze if storage longer than 72 hours is needed. |
| Patient Preparation | | Patient must be fasting 12-14 hours. |
| Causes for Rejection | | Specimen from nonfasting patient |
| Reference Interval | | Male: 110-180 mg/dL; female: 110-205 mg/dL |
| 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 |
| Footnotes | | - 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):385-9
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