Coombs Test - Indirect
Understanding Coombs Test - Indirect
What is Coombs Test - Indirect?
The Indirect Coombs Test (ICT) is also called as Indirect Antiglobulin Test. It is performed to identify the presence or absence of antibodies in blood directed against antigens found on red blood cells.
ICT test is done at the time of donating blood, tissue, or organ, before receiving blood during the transfusion to determine the compatibility with donated blood, and during pregnancy to determine the risk of incompatibility between mother and fetus.
The Indirect Coombs Test is performed on the principle of the antigen-antibody reaction. It is used to detect very low concentrations of antibodies present in a patient’s plasma. The ICT can also be used for compatibility testing, antibody identification, RBC phenotyping, and titration studies.
What is Coombs Test - Indirect used for?
· At the time of donating blood, tissue, organ, or bone marrow or while getting registered as a potential donor
· Before receiving a blood transfusion or blood components transfusion to determine compatibility with donated blood
· Before pregnancy and during pregnancy to determine the risk of incompatibility between the mother and fetus
· To determine if hemolytic anemia is caused due to an autoimmune disorder
Interpreting Coombs Test - Indirect results
Interpretations
Agglutination: Positive result, antibodies present
No agglutination: Negative result, antibodies absent
Result | Interpretation |
Negative | No antibodies detected |
Equivocal | Positive in undiluted serum up to 1:16 titre |
Positive | Positive in titre of 1:32 or above Positive in increasing titre in subsequent tests |
Antibodies are produced in the blood upon exposure to incompatible antigens as during a blood transfusion. Antibodies produced in the first incompatible transfusion produce severe reactions upon subsequent transfusions of the same blood type.
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Coombs Test - Indirect
Frequently Asked Questions about Coombs Test - Indirect
Q. Is there any risk associated with this test?
Q. What other tests can be prescribed by your doctor in case of abnormal Indirect Coombs test result?
Q. What else can the Indirect Coombs Test be used for?
Q. What is the difference between Indirect and Direct Coombs Tests?
Q. What is HDFN?
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