Order Code: C122

Synonyms: A1 Apolipoprotein; ApoA1

Special Instructions: State patient’s gender on the requisition form form.

Sample Type: Serum

Minimum Volume: 0.5 mL

Tube type: Tiger top tube

Patient Preparation:

Collection:
1. Draw sample and gently invert 5 times (DO NOT SHAKE!)
2. Let the blood clot for 30 minutes
3. Centrifuge sample at 1300 rcf for 30 minutes

Storage Instructions: Cleveland HeartLab recommends that the sample be stored at 4°C and shipped same day as draw.  The sample is stable for 7 days at 4°C.

Causes for Rejection: Samples will be rejected if there is gross hemolysis or if the sample is improperly labeled

Goal Value:
Male: >120 mg/dL
Note: If a gender is not provided, the result will default to the male goal value.

Use: ApoA1 levels are measured to determine an individual’s risk of developing cardiovascular disease (CVD). ApoA1 may be measured when an individual has a personal or family history of abnormal lipid levels (hyperlipidemia) and/or premature CVD. It may be ordered when a doctor is trying to determine the cause of an individual’s hyperlipidemia and/or suspects it may be due to a disorder that is causing a deficiency in ApoA1. ApoA1 may be ordered along with ApoB when a doctor wants to check an ApoB/ApoA1 ratio as a CVD risk indicator, to evaluate the "bad" to "good" cholesterol. ApoA1 may be ordered, along with other tests, when an individual has undergone lipid-lowering treatment or lifestyle changes, such as decreased dietary fat and increased regular exercise, to monitor the effectiveness of the changes.

Methodology: Immunoturbidometric

Additional Information: Low levels of ApoA1 are associated with low levels of HDL and impaired clearance of excess cholesterol from the body. Low levels of ApoA1, along with high concentrations of ApoB, are associated with an increased risk of cardiovascular disease. There are some genetic disorders that lead to deficiencies in ApoA1 (and therefore to low levels of HDL). Individuals with these disorders tend to have hyperlipidemia and high levels of low-density lipoprotein (LDL – the "bad" cholesterol). Frequently, they have accelerated rates of atherosclerosis. These genetic disorders are primary causes of low ApoA1.

Some of the conditions that contribute to changes in ApoA1 levels are listed below:

ApoA1 levels may decrease with: Chronic renal failure, certain drugs (androgens, beta blockers, diuretics, and progestins (synthetic progesterone)), smoking, and uncontrolled diabetes.

ApoA1 levels may increase with: Certain drugs (carbamazepine, estrogens, ethanol, lovastatin, niacin, oral contraceptives, phenobarbital, pravastatin, and simvastatin), physical exercise, pregnancy and weight reduction.