The sugar-water hemolysis test is a blood test to detect fragile red blood cells by testing their ability to withstand swelling in a low-salt solution.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
There is no special preparation needed for this test.
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
Your doctor may order this test if you have signs or symptoms of paroxysmal nocturnal hemoglobinuria (PNH) or hemolytic anemia of unknown cause. PNH red blood cells are very likely to be harmed by the body's complement system. The complement system is a group of proteins that move freely through the bloodstream. The proteins work with the immune system.
- Negative: less than 5% red blood cell breakdown (hemolysis)
- Positive: more than 10% hemolysis
A negative test does not rule out PNH. False-negative results may occur if the fluid part of blood (serum) lacks complement.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
- Paroxysmal nocturnal hemoglobinuria (PNH)
- Autoimmune hemolytic anemias and leukemia may give false positive result
There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient 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
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Sucrose hemolysis test
Brodsky RA. Paroxysmal nocturnal hemoglobinuria. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al., eds.Hematology: Basic Principles and Practice
Elghetany M, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods
Update Date 2/24/2014
Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.