Apolipoprotein CII (apoCII) is a protein found in large particles absorbed from the gastrointestinal tract. It is also found in very low density lipoprotein (VLDL), which is made up of mostly cholesterol.

This article discusses the test used to check for apoCII in a sample of your blood.

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

You may be told not to eat or drink anything for 4 - 6 hours before the test.

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

ApoCII measurements can help to determine the specific type or cause of high blood lipids (hyperlipidemia).

Usually, apoCII is reported as present or absent. If the specific level is measured, the normal value may vary according to the institution performing the test.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

High levels of apoCII may be due to:

• Angina pectoris
• Familial lipoprotein lipase deficiency
• Heart attack

Low apoCII levels are seen in persons with a rare condition called familial apoprotein CII deficiency.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)