Coombs Test, Direct

The Coombs Test is a blood test used to detect antibodies that act against red blood cells. It's primarily used to diagnose immune-related causes of anaemia, such as autoimmune haemolytic anaemia, or to check for blood compatibility issues (e.g., in new-borns or before transfusions).

Why Consider Coombs test?

Detects antibodies or complement proteins attached directly to the surface of red blood cells.

Used To Diagnose Coombs Test:

• Autoimmune hemolytic anemia
• Hemolytic disease of the newborn (due to Rh incompatibility)
• Reactions to blood transfusions
• Drug-induced hemolysis

Who Should Consider Coombs Test?

• Unexplained hemolytic anemia
• Jaundice in newborns
• After a blood transfusion reaction
• Suspected drug-induced hemolysis

More About Direct Coombs test ?

The Direct Coombs Test is a blood test used to detect antibodies or complement proteins that are bound directly to the surface of red blood cells (RBCs). These immune proteins can cause destruction (hemolysis) of the RBCs, leading to hemolytic anemia.

What Does a Positive Result Mean?

A positive Direct Coombs Test means there are antibodies or complement proteins attached to your red blood cells.

This suggests an immune cause of hemolysis, such as:

🧬 Autoimmune Hemolytic Anemia (AIHA)

• The body produces antibodies against its own red blood cells.
• Can be warm AIHA (IgG active at body temp) or cold AIHA (IgM active at cold temps).

Hemolytic Transfusion Reaction

• Happens when your immune system attacks transfused red cells that aren't a good match.
• Hemolytic Disease of the Newborn (HDN)
• Occurs when a mother's antibodies cross the placenta and attack the baby's red cells (especially in Rh incompatibility).

Drug-Induced Hemolysis

• Certain drugs (like penicillin, methyldopa, or cephalosporins) can cause the immune system to destroy red cells.