Pyruvate kinase blood test
The pyruvate kinase test measures the level of pyruvate kinase enzyme in the blood.
Pyruvate kinase is an enzyme found in red blood cells. It helps change sugar in the blood (glucose) to energy when oxygen levels are low.
Enzyme
Enzymes are complex proteins that cause a specific chemical change. For example, they can help break down the foods we eat so the body can use them....
How the Test is Performed
A blood sample is needed. In the laboratory, white blood cells are removed from the blood sample because they can alter test results. The level of pyruvate kinase is then measured.
Blood sample
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
How to Prepare for the Test
No special preparation is necessary.
If your child is having this test, it may help to explain how the test will feel and even demonstrate on a doll. Explain the reason for the test. Knowing the how and why may reduce your child's anxiety.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
This test is done to detect an abnormally low level of pyruvate kinase. Without enough of this enzyme, red blood cells break down faster than normal. This is called hemolytic anemia.
Hemolytic anemia
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Normally, red ...
This test helps diagnose pyruvate kinase deficiency (PKD).
Pyruvate kinase deficiency (PKD)
Pyruvate kinase deficiency is an inherited lack of the enzyme pyruvate kinase, which is used by red blood cells. Without this enzyme, red blood cell...
Normal Results
Results vary depending on the testing method used. In general, a normal value is 5.5 to 12.4 U/g Hb.
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
A low level of pyruvate kinase confirms PKD.
Risks
There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
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Fainting or feeling lightheaded
Fainting
Fainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...
Read Article Now Book Mark Article - Multiple punctures to locate veins
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Hematoma (blood buildup under the skin)
Hematoma
A bruise is an area of skin discoloration. A bruise occurs when small blood vessels break and leak their contents into the soft tissue beneath the s...
Read Article Now Book Mark Article - Infection (a slight risk any time the skin is broken)
References
Elghetany MT, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 33.
Gallagher PG. Hemolytic anemias: red cell membrane and metabolic defects. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 147.
Papachristodoulou D. Energy metabolism. In: Naish J, Syndercombe Court D, eds. Medical Sciences. 3rd ed. Philadelphia, PA: Elsevier; 2019:chap 3.
Rab MAE, van Wijk R. Enzymes of the red blood cell. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2023:chap 78.
Review Date: 3/31/2024
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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