In immunology, AHG stands for Anti-human globulin.
AHG reagents are a critical component in certain laboratory tests, particularly within transfusion medicine. They are used to detect antibodies that are attached to red blood cells but may not cause visible clumping (agglutination) on their own.
Understanding AHG Reagents
Based on the provided reference, Anti-human globulin (AHG) reagents are widely applied in pretransfusion compatibility tests. These tests are essential to ensure that a patient receives blood that is safe and compatible with their own, minimizing the risk of adverse reactions.
AHG reagents work by bridging the gaps between antibody-coated red blood cells, causing them to agglutinate, which is a visible sign that antibodies are present.
Key Applications
- Pretransfusion Compatibility Testing: This is the primary application mentioned in the reference. It includes tests like the Direct Antiglobulin Test (DAT) and the Indirect Antiglobulin Test (IAT).
- DAT: Detects antibodies already attached to a patient's red blood cells in vivo.
- IAT: Detects antibodies in a patient's serum that could react with donor red blood cells in vitro.
Factors Affecting AHG Test Accuracy
According to the reference, the accuracy of detection with AHG reagents is mainly affected by irregular antibodies or cold agglutinins in blood samples, which are related to the human complement system.
- Irregular Antibodies: These are antibodies, other than ABO antibodies, that can react with red blood cells. They can be acquired through transfusion or pregnancy.
- Cold Agglutinins: These are antibodies that react optimally at temperatures below body temperature.
- Complement System: The human complement system is a part of the immune system. Antibodies can activate complement, and AHG reagents often contain antibodies against complement components as well as human antibodies (immunoglobulins). The presence of certain antibodies or activated complement can interfere with AHG testing accuracy.
Understanding these factors is crucial for laboratory professionals to perform accurate pretransfusion testing and ensure patient safety.
