What could explain reactive results at the IAT phase with a negative autocontrol?

What could explain reactive results at the IAT phase with a negative autocontrol?

• A. A cold alloantibody
• B. High-frequency alloantibody or a mixture of alloantibodies
• C. A warm autoantibody
• D. A cold and warm alloantibody

Answer: (B)

Reactive results at the Indirect Antiglobulin Test (IAT) phase with a negative autocontrol can often be attributed to the presence of a high-frequency alloantibody or a mixture of alloantibodies. In the context of blood banking and immunohematology, a high-frequency alloantibody targets specific antigen types that are found on the majority of red blood cells, meaning that the likelihood of encountering such an antigen in typical blood donors is quite high. Consequently, if an individual has formed an alloantibody against these common antigens, it will react in the presence of corresponding antigens in the test red blood cells, resulting in a positive IAT phase. However, because the autologous (self) red blood cells do not display the antigens targeted by this antibody, the autocontrol will remain negative. Additionally, the presence of a mixture of several alloantibodies can lead to similar outcomes. If the individual's immune system has produced multiple antibodies against several different red blood cell antigens, at least one of these may react positively in the IAT, while the self-red blood cells do not contain the antigen that the reacting antibody is targeting. This explanation clarifies why the other answers do not fit as well.

Reactive results at the Indirect Antiglobulin Test (IAT) phase with a negative autocontrol can often be attributed to the presence of a high-frequency alloantibody or a mixture of alloantibodies.

In the context of blood banking and immunohematology, a high-frequency alloantibody targets specific antigen types that are found on the majority of red blood cells, meaning that the likelihood of encountering such an antigen in typical blood donors is quite high. Consequently, if an individual has formed an alloantibody against these common antigens, it will react in the presence of corresponding antigens in the test red blood cells, resulting in a positive IAT phase. However, because the autologous (self) red blood cells do not display the antigens targeted by this antibody, the autocontrol will remain negative.

Additionally, the presence of a mixture of several alloantibodies can lead to similar outcomes. If the individual's immune system has produced multiple antibodies against several different red blood cell antigens, at least one of these may react positively in the IAT, while the self-red blood cells do not contain the antigen that the reacting antibody is targeting.

This explanation clarifies why the other answers do not fit as well.