Anti-P antibody; Paroxysmal cold hemoglobinuria - Donath-Landsteiner
The Donath-Landsteiner test is a blood test to detect harmful antibodies related to a rare disorder called paroxysmal cold hemoglobinuria. These antibodies form and destroy red blood cells when the body is exposed to cold temperatures.
How to Prepare for the Test
No special preparation is needed.
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 confirm a diagnosis of paroxysmal cold hemoglobinuria.
The test is considered normal if no Donath-Landsteiner antibodies are present. This is called a negative result.
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
Abnormal results mean Donath-Landsteiner antibodies are present. This is a sign of paroxysmal cold hemoglobinuria.
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
- Fainting or feeling lightheaded
- Multiple punctures to locate veins
- Hematoma (blood buildup under the skin)
- Infection (a slight risk any time the skin is broken)
Elghetany MT, Schexneider KI, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 32.
Michel M. Autoimmune and intravascular hemolytic anemias. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 160.