direct Coombs test

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

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

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

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

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

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

Immune mediated hemolytic anemia (direct Coombs test is positive)

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

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

If the direct Coombs test is positive, hemolysis is caused by an immune process (e.g. autoimmune hemolytic anemia).

Two blood tests can check for antibodies that attack red blood cells: the direct Coombs test and the indirect Coombs test.

Hematologic: Hemolytic anemia (direct Coombs test is positive) and various cytopenias, and bleeding (caused by thrombocytopenia) can occur.

The direct Coombs test is used clinically when immune-mediated hemolytic anemia (antibody-mediated destruction of RBCs) is suspected.

They are most commonly found in immunologically-mediated hemolytic anemias and in hereditary spherocytosis, but the former would have a positive direct Coombs test and the latter would not.

Alloimmunity (The neonatal or cord blood gives a positive direct Coombs test and the maternal blood gives a positive indirect Coombs test)

Coombs reagent (also known as Coombs antiglobulin or antihuman globulin) is used in both the direct Coombs test and the indirect Coombs test.

If this produces agglutination of RBCs, the direct Coombs test is positive, a visual indication that antibodies (and/or complement proteins) are bound to the surface of red blood cells.

If immunoglobulin or complement factors have been fixed on to the RBC surface in-vivo, the antihuman globulin will agglutinate the RBCs and the direct Coombs test will be positive.

The direct Coombs test (also known as the direct antiglobulin test or DAT) is used to detect if antibodies or complement system factors have bound to RBC surface antigens in vivo.

In about a third of all ABO incompatible pregnancies maternal IgG anti-A or IgG anti-B antibodies pass through the placenta to the fetal circulation leading to a weakly positive direct Coombs test for the neonate's blood.

The two Coombs tests are the direct Coombs test (DCT, also known as direct antiglobulin test or DAT), and the indirect Coombs test (also known as indirect antiglobulin test or IAT).

The Direct Coombs test is used to test for autoimmune hemolytic anemia; ie, a condition of a low count of red blood cells (aka RBCs) caused by immune system lysis or breaking of RBC membranes causing RBC destruction.

The direct Coombs test is used to detect these antibodies or complement proteins that are bound to the surface of red blood cells; a blood sample is taken and the RBCs are washed (removing the patient's own plasma) and then incubated with antihuman globulin (also known as "Coombs reagent").