Definition
Apolipoprotein CII (apoCII) is a protein found in large fat particles that the gastrointestinal tract absorbs. It is also found in very low density lipoprotein (VLDL), which is made up of mostly triglycerides (a type of fat in your blood).
This article discusses the test used to check for apoCII in a sample of your blood.
Alternative Names
ApoCII; Apoprotein CII; ApoC2; Lipoprotein lipase deficiency - apolipoprotein CII; Chylomicronemia syndrome - apolipoprotein CII
How the Test is Performed
How to Prepare for the Test
You may be told not to eat or drink anything for 4 to 6 hours before the test.
How the Test will Feel
When the needle is inserted to draw blood, you may feel some pain, or only a prick or stinging. Afterward, there may be some throbbing where the needle was inserted.
Why the Test is Performed
ApoCII measurements can help determine the type or cause of high blood fats. It is not clear whether the test results improve treatment. Because of this, most health insurance companies will not pay for the test. If you do not have high cholesterol or heart disease or a family history of these conditions, this test may not be recommended for you.
Normal Results
The normal range is 3 to 5 mg/dL. However, apoCII results are usually reported as present or absent.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.
What Abnormal Results Mean
High levels of apoCII may be due to a family history of lipoprotein lipase deficiency. This is a condition in which the body does not break down fats normally.
Low ApoCII levels are also seen in people with a rare condition called familial apoprotein CII deficiency. This causes chylomicronemia syndrome, another condition in which the body does not break down fats normally.
Risks
Risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Considerations
Apolipoprotein measurements may provide more detail about your risk for heart disease, but the added value of this test beyond a lipid panel is unknown.
References
Bredefeld CL, Lau R, Hussain MM. Lipids and dyslipoproteinemia. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. St Louis, MO: Elsevier; 2022:chap 18.
Genest J, Mora S, Libby P. Lipoprotein disorders and cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 27.
Libby P. The Vascular biology of atherosclerosis. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 24.
Meeusen JW, Ueda M, Nordestgaard BG, Remaley AT. Lipids and lipoproteins. In: Rifai N, Chiu RWK, Young I, Burnham C-A D, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 36.
Mora S, Martin SS. Measurement of low-density lipoprotein cholesterol, non–high-density lipoprotein cholesterol, apolipoprotein B, and low-density lipoprotein particle concentration. In: Ballantyne CM, ed. Clinical Lipidology: A Companion to Braunwald's Heart Disease. 3rd ed. Philadelphia, PA: Elsevier; 2024:chap 3.
Robinson JG. Disorders of lipid metabolism. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 190.
