Donath-Landsteiner test
Key points
- This is a test that detects the Donath-Landsteiner antibody in serum (the portion of blood without cells), which may be related to paroxysmal cold hemoglobinuria.
- Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand.
- The preparation you can provide for this test depends on your child's age, previous experience, and level of trust.
- This test is sometimes performed when the diagnosis of paroxysmal cold hemoglobinuria is suspected.
Alternative names
Anti-P antibody
Definition
This is a test that detects the Donath-Landsteiner antibody in serum (the portion of blood without cells), which may be related to paroxysmal cold hemoglobinuria.
How the test is performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes vein to swell with blood.
A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. 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:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to prepare for the test
No special preparation is needed.
In infants and children:
The preparation you can provide for this test depends on your child's age, previous experience, and level of trust. For general information regarding how you can prepare your child, see the following:
- infant test or procedure preparation (birth to 1 year)
- toddler test or procedure preparation (1 to 3 years)
- preschooler test or procedure preparation (3 to 6 years)
- schoolage test or procedure preparation (6 to 12 years)
- adolescent test or procedure preparation (12 to 18 years)
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This test is sometimes performed when the diagnosis of paroxysmal cold hemoglobinuria is suspected.
Normal Values
No presence of antibodies is normal.
What abnormal results mean
Written and revised by
David Cohen, M.D.
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