The Coombs’ test is a blood test of the immune system. There are 2 types of Coombs’ tests:
The Coombs’ test checks for antibodies that may attack red blood cells. Antibodies are the proteins the immune system makes to fight infections, such as the flu and measles. The direct Coombs' test looks for antibodies that are already attached to the red blood cells. The indirect Coombs' test looks for antibodies that are free floating in the bloodstream. Many diseases and drugs can cause the antibodies to develop. They may also develop if your child is exposed to foreign red blood cells, like during a blood transfusion.
This test may be done to help diagnose a medical problem, such as jaundice, anemia, lupus, or mononucleosis. A newborn may have this test if there is a concern that the mother’s antibodies may attack the baby’s red blood cells. If your child is going to have a blood transfusion, the test may be done to help check for blood that will be a good match.
Usually no preparation is needed for this test.
Talk to your healthcare provider if you have any questions about the test.
A small amount of blood is taken from a finger with a fingerstick or from a vein in your child’s arm with a needle. Your child's healthcare provider may make a tiny cut in the baby's heel to get a small amount of blood to test. The blood is collected in tubes and sent to a lab.
Ask your healthcare provider when and how you will get the result of your child’s test.
Some of the conditions that have a positive Coombs’ test result are:
Test results are only one part of a larger picture that takes into account your child’s medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the result and ask questions, such as: