In a neonate ABO typing pattern with Anti-A 0, Anti-B 3+, A cells 0, B cells 0, which is most probable blood type?

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

Answer: (D)

Forward typing uses antisera to see which ABO antigens are on the patient’s red cells. Here, anti-B causes strong agglutination while anti-A does not, so the red cells carry the B antigen but not A antigen—consistent with blood type B.

In a neonate, the reverse typing (plasma against A and B cells) often shows little or no reactivity because the infant hasn’t developed significant ABO antibodies yet. The results showing no reaction with A cells or B cells fit this neonatal pattern and do not contradict B antigen on the cells.

Therefore, the most probable blood type is Group B.