What is this test?
- This laboratory test is performed on a blood sample to detect antibodies or anti-globulins that are reactive against red blood cells. This is an abnormal function of antibodies. Normally, antibodies are proteins that react against harmful objects in the body. Direct coombs test detects the antibodies attached to the surface of red blood cells.
Why is this test performed?
This test is performed to:
- Diagnose the cause of red blood cell destruction
- To investigate the blood transfusion reaction
- To detect the presence of mother antibodies against the fetus that cause hemolytic disease of the new born.
- What is the difference between direct and indirect coombs test?
There are two types of coombs test:
- Direct coombs test
- Indirect coombs test
Direct coombs test detects the presence of antibodies reactive against RBCs stuck to the surface of RBCs while indirect coombs test detects the presence of antibodies roaming freely in the serum.
- What are the causes of a positive coombs test?
A positive direct coombs test may be due to:
- Incompatible blood transfusion
- Hemolytic anemia
- Hemolytic disease of the newborn
- Lymphoma
- Autoimmune disorder
- Medicines such as penicillin.
- What are the symptoms of blood transfusion reaction?
Following are the symptoms after an incompatible blood transfusion:
- Bloody urine
- Fever
- Chills
- Back pain.
- What are the symptoms of HDN (hemolytic disease of newborn)?
Following are the symptoms of HDN:
- Jaundice
- Pale skin
- Enlarged liver or spleen
- Difficulty breathing
- Swelling in the whole body.
- How to prepare for this test?
No special preparations are required for this test. However, inform your doctor about your complete medical history.