How likely is an A2 or A2B person likely to form an anti-A1 if transfused with group A donor blood? I've just been wondering this for awhile. Are there any studies out there on this issue? As far as I know, 20% of all group A or AB individuals have a subgroup of A. And, 99% of these subgroup of A individuals are A2. Also, does an anti-A2 exist? For example, can an A1 person who was transfused with A2 donor blood form an anti-A2? Thanks!!!  