The antigen Tj^a is a part of which blood group system?

The antigen Tj^a is a part of which blood group system?

• A. P
• B. MNSs
• C. Lewis
• D. Kell

Answer: (A)

Tj^a is a P-system antigen. In immunohematology, antigens are organized into discrete blood group systems, and Tj^a belongs to the P system, which includes related P family antigens such as P and P1. The other listed systems—MNSs, Lewis, and Kell—are separate groups with their own distinct antigen sets, so an antibody directed against Tj^a would be classified as a P-system antibody rather than belonging to MNSs, Lewis, or Kell. This is why the correct system is the P blood group system.

Tj^a is a P-system antigen. In immunohematology, antigens are organized into discrete blood group systems, and Tj^a belongs to the P system, which includes related P family antigens such as P and P1. The other listed systems—MNSs, Lewis, and Kell—are separate groups with their own distinct antigen sets, so an antibody directed against Tj^a would be classified as a P-system antibody rather than belonging to MNSs, Lewis, or Kell. This is why the correct system is the P blood group system.