Direct antihuman globulin test (DAT)

Definition

The Direct Antihuman Globulin Test (DAT), also known as the direct Coombs test, detects antibodies or complement proteins attached to the surface of red blood cells. It is used to diagnose conditions like autoimmune hemolytic anemia and hemolytic disease of the newborn.

5 Must Know Facts For Your Next Test

1. DAT involves adding antihuman globulin to a patient's washed red blood cells to check for agglutination.
2. A positive DAT indicates that antibodies or complement are bound to the red blood cell surface in vivo.
3. Common causes for a positive DAT include autoimmune hemolytic anemia, drug-induced hemolysis, and transfusion reactions.
4. In newborns, a positive DAT can indicate hemolytic disease due to Rh or ABO incompatibility.
5. The test does not specify which antibody or complement component is present; further testing is required for identification.

Related terms

Indirect Antihuman Globulin Test (IAT): Detects free antibodies in the serum by mixing them with red blood cells and antihuman globulin.

Autoimmune Hemolytic Anemia: A condition where the immune system produces antibodies that attack its own red blood cells.

Hemolytic Disease of the Newborn:

A condition where maternal antibodies attack fetal red blood cells, leading to hemolysis.