ABOcompatible

ABOcompatible refers to a match between donor and recipient within the ABO blood group system that minimizes immune reactions during medical procedures such as blood transfusion and organ transplantation. The ABO system classifies blood into four groups—A, B, AB, and O—based on the presence or absence of A and B antigens on red blood cells and the corresponding antibodies in plasma.

In red blood cell transfusion, compatibility means the recipient’s anti-A and anti-B antibodies do not attack the donor's red cells. The goal is to prevent acute hemolytic reactions. Universal policies often favor using O type red cells for emergencies and ABO-identical matching when possible. For plasma transfusions, the considerations differ because plasma contains antibodies; for example, AB plasma lacks anti-A and anti-B antibodies and is generally compatible with recipients of any ABO type, whereas plasma from other groups contains antibodies that can react with certain recipients.

In organ transplantation, ABO compatibility is a major determinant of graft survival and rejection risk. Most programs require ABO-identical or compatible donors and recipients and perform crossmatching to detect donor-specific antibodies. In some cases, ABO-incompatible transplants are performed at specialized centers using desensitization protocols and careful individualized management.

Testing to determine ABO compatibility involves serologic blood typing of the donor and recipient (forward and reverse typing) and crossmatching to detect antibodies against donor antigens. Advances in immunology and transplantation have enhanced the precision of compatibility assessment, including virtual crossmatching and genetic typing for rare variants. Overall, ABO compatibility remains a foundational principle in transfusion medicine and transplantation to minimize immune-mediated complications.