Which ABO blood type has antigen A and anti-B antibodies?

Which ABO blood type has antigen A and anti-B antibodies?

• A. Type A
• B. Type B
• C. Type AB
• D. Type O

Answer: (A)

Antigens on red blood cells and antibodies in plasma determine ABO compatibility. Type A blood has A antigens on the red blood cells and anti-B antibodies in the plasma. This specific pattern—A antigen present with anti-B antibodies present—fits Type A. In contrast, Type B would have B antigens with anti-A antibodies; Type AB has both A and B antigens but no anti-A or anti-B antibodies; Type O has neither antigen and carries both anti-A and anti-B antibodies. So the combination described is characteristic of Type A.

Antigens on red blood cells and antibodies in plasma determine ABO compatibility. Type A blood has A antigens on the red blood cells and anti-B antibodies in the plasma. This specific pattern—A antigen present with anti-B antibodies present—fits Type A. In contrast, Type B would have B antigens with anti-A antibodies; Type AB has both A and B antigens but no anti-A or anti-B antibodies; Type O has neither antigen and carries both anti-A and anti-B antibodies. So the combination described is characteristic of Type A.