Coombs Test - Direct Test

The Coombs Direct Test is performed to measure the level of antibodies attached to the Red Blood Cells in the blood. The test helps detect haemolytic anaemia, Rh negative pregnancy, and transfusion reactions. Your doctor might ask you to get the test done if you have haemolytic anaemia and he or she wants to find out the cause. You might also be asked to get the test done if you have symptoms such as bloody urine, back pain, chills, etc.

You do not need to prepare specifically for the test. You have to make sure that you have gathered all the information from your doctor and are well aware of the process and the medications. Apart from this, your doctor would also like to know the medicines or supplements you take as certain medications can affect the test.

After analysing your blood sample, the results come out. A positive test result means that there are antibodies attached to the RBCs. The more positive the test result, the greater is the number of antibodies attached to the RBCs. A negative test result means that there are no antibodies attached to the RBCs and the signs and symptoms experienced are caused by other reasons.

For the test, your doctor or lab technician will place a plastic band on your upper arm; this is done to fill up the vein with blood and swell up. Then, he or she will clean the area with an antiseptic and put a needle. He will then draw a blood and keep it in a vial or tube. The plastic band and needle are removed and a bandage is applied to the area to stop the bleeding. The whole process usually takes a few minutes. The collected blood is then sent to the lab for analysis.