Soluble antigens in plasma allow mismatched transfusion without hemolysis

Abstract

Our study shows that secretor status would provide protection from isoantibodies. The dissolved B antigens in the group B plasma absorb and/or bind to the group B isoantibodies in the group A plasma. This mechanism gives a protective effect against hemolytic reactions in massive transfusion situations in the trauma setting when group A plasma is used instead of group AB plasma. This protective effect is revealed with the paucity of intravascular hemolysis observed in these out-of-group massive transfusions.

Safety of the use of group A plasma in trauma: the STAT study

“…These transfused group O RBCs reduce the volume of the autologous RBCs that could be susceptible to hemolysis from group A plasma. Second, 80% of group B and AB recipients (i.e., those who are potentially susceptible to hemolysis from group A plasma) will be secretors of soluble B substance that would neutralize the anti‐B present in the group A thawed plasma . Third, the experience from the transfusion of minor mismatched platelets (PLTs) has demonstrated that hemolysis from group A PLTs is uncommon .…”

Immunologic risks of whole blood: ABO compatibility, D alloimmunization, and transfusion‐related acute lung injury

“…Although ABO‐incompatible platelet and plasma transfusions both result in the transfusion of anti‐A and/or anti‐B antibodies, concern for clinically significant hemolysis in the transfusion recipient is low. This is due to several protective factors, including the presence of A and B antigen on endothelial cells, dilution of transfused plasma into the patient blood volume, and soluble A and B antigen in the plasma of secretors . All of these factors serve to decrease risk for hemolysis of recipient red cells.…”

“…However, higher titers do not guarantee hemolysis in the incompatible recipient as reported from one center where 26% of group O apheresis platelets had anti‐A and/or anti‐B IgG titers > 256 and almost 10% had titers > 512 without evidence of hemolysis . Variables such as antibody subclass and soluble ABH antigens that exist in approximately 80% of the population may help explain why hemolysis is a rare complication of incompatible plasma transfusion . The absolute amount of incompatible anti‐A and anti‐B that can be safely transfused to recipients has yet to be defined.…”

“…This is due to several protective factors, including the presence of A and B antigen on endothelial cells, dilution of transfused plasma into the patient blood volume, and soluble A and B antigen in the plasma of secretors. 8 All of these factors serve to decrease risk for hemolysis of recipient red cells.…”

“…18 Variables such as antibody subclass and soluble ABH antigens that exist in approximately 80% of the population may help explain why hemolysis is a rare complication of incompatible plasma transfusion. 8 The absolute amount of incompatible anti-A and anti-B that can be safely transfused to recipients has yet to be defined.…”