Which reaction would be identical for both A1 and A2 individuals?

Which reaction would be identical for both A1 and A2 individuals?

• A. Positive reaction with anti-A1 lectin
• B. Positive reaction with A1 cells
• C. Equal reaction with anti-H
• D. Positive reaction with anti-A,B

Answer: (D)

A1 and A2 individuals both belong to the A blood group but have different subgroups based on their expression of the A antigen. Specifically, A1 individuals have a higher expression of A antigens than A2 individuals, but both subgroups contain the A antigen. Therefore, when tested with anti-A,B serum, both A1 and A2 individuals will show a positive reaction. This serum detects the presence of the A antigen, which is present in both subgroups. In contrast, anti-A1 lectin would only react with A1 cells, and A1 individuals would show a positive reaction while A2 individuals would not. A1 cells would similarly yield a positive reaction only for A1 individuals and not for A2. The reaction with anti-H can vary based on the individual’s red blood cell composition and is not specific to A subgroup differences, but rather the H antigens present in all ABO groups. Thus, the equal reaction with anti-A,B is the only reaction where both A1 and A2 individuals would exhibit the same response, emphasizing the commonality of the A antigen in both subgroups.

A1 and A2 individuals both belong to the A blood group but have different subgroups based on their expression of the A antigen. Specifically, A1 individuals have a higher expression of A antigens than A2 individuals, but both subgroups contain the A antigen. Therefore, when tested with anti-A,B serum, both A1 and A2 individuals will show a positive reaction. This serum detects the presence of the A antigen, which is present in both subgroups.

In contrast, anti-A1 lectin would only react with A1 cells, and A1 individuals would show a positive reaction while A2 individuals would not. A1 cells would similarly yield a positive reaction only for A1 individuals and not for A2. The reaction with anti-H can vary based on the individual’s red blood cell composition and is not specific to A subgroup differences, but rather the H antigens present in all ABO groups.

Thus, the equal reaction with anti-A,B is the only reaction where both A1 and A2 individuals would exhibit the same response, emphasizing the commonality of the A antigen in both subgroups.