Coombs antiglobulin reaction
Coombs test

The direct Coombs test is done on a sample of red blood cells from the body.

Agglutination of red blood cells is used in the Coombs test.

The direct Coombs test finds antibodies attached to your red blood cells.

At greater dilutions the indirect Coombs test is negative.

If agglutination occurs, the indirect Coombs test is positive.

Additional clinical findings may include positive Coombs test results, hypoglycemia, and dehydration.

A direct Coombs test is also done on the patient's blood sample in case there are any confounding antibodies.

Coombs test, an aid to medical diagnosis.

Diagnosis is made by a positive direct Coombs test, other lab tests, and clinical examination and history.

A direct antiglobulin test (Coombs test) is also performed as part of the antibody investigation.

Direct Coombs test, used to test for autoimmune hemolytic anemia.

The venous blood is taken to a laboratory (or blood bank), where trained scientific technical staff do the Coombs tests.

(A visual representation of a positive direct Coombs test is shown in the upper half of the schematic).

The indirect Coombs test is used to screen for antibodies in the preparation of blood for blood transfusion.

(A cross match is shown visually in the lower half of the schematic as an example of an indirect Coombs test).

Immune mediated hemolytic anemia (direct Coombs test is positive)

Coombs tests are done on serum from venous blood samples which are taken from patients by venepuncture.

The clinical significance of the result is assessed by the physician who requested the Coombs test, perhaps with assistance from a laboratory-based hematologist.

For example, the indirect Coombs test detects the presence of anti-Rh antibodies in a pregnant woman's blood serum.

The direct Coombs test is used to confirm that the fetus or neonate has an immune mediated hemolytic anemia.

A positive Coombs test indicates that an immune mechanism is attacking the patient's own RBC's.

Antibodies directed against red blood cell surface antigens in immune mediated hemolytic anemia are detected with the Coombs test.

To determine the autoantibody or autoantibodies present in a patient, the Coombs test, also known as the antiglobulin test, is performed .

The indirect Coombs test is used in prenatal testing of pregnant women, and in testing blood prior to a blood transfusion.

Infections (Note: Direct Coombs test is sometimes positive in hemolytic anemia due to infection)