Apolipoprotein B

CPT Code: 82172

Order Code: C123

Synonyms: ApoB, Apo B100, Beta Apolipoprotein

Specimen: Serum

Minimum Volume: 0.5ml

Tube Type: Tiger top tube

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 at 6 days at 4°C.

Patient Preparation: Patient must be fasting 12 to 14 hours

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

Goal Value: <100 mg/dL

Use: ApoB levels are used, along with other lipid tests, to help determine an individual's risk of developing cardiovascular disease (CVD). The test is not used as a general population screen but may be ordered if a person has a family history of heart disease and/or hyperlipidemia. It may be performed, along with other tests, to help diagnose the cause of hyperlipidemia, especially when someone has elevated triglyceride levels, which can prevent accurate LDL cholesterol calculations. ApoB levels may be ordered 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). In rare cases, an ApoB test may be ordered to help diagnose a genetic problem that causes over- or under-production of ApoB.

Methodology: Immunoturbidimetric

Additional Information: Elevated levels of ApoB correspond to elevated levels of LDL-C and to non-HDL-C and are associated with an increased risk of CVD. Elevations may be due to a high fat diet and/or decreased clearing of LDL from the blood. Some genetic disorders are the direct (primary) cause of abnormal levels of ApoB. For example, familial combined hyperlipidemia is an inherited disorder causing high blood levels of cholesterol and triglycerides. Abetalipoproteinemia, also called ApoB deficiency or Bassen-Kornzweig Syndrome, is a very rare genetic condition that can cause abnormally low levels of ApoB.

ApoB levels may be increased with: Diabetes, use of certain drugs (androgens, beta blockers, diuretics, progestins (synthetic progesterones)), hypothyroidism, nephrotic syndrome (a kidney disease), pregnancy (levels increase temporarily and decrease again after delivery).