A role for red cell clearance in antibody ‐mediated inhibition of erythrocyte alloimmunization?

Antibodies targeting erythrocytes can induce antibody‐mediated inhibition of erythrocyte alloimmunization, and anti‐D has been extremely successful in preventing haemolytic disease of the foetus and newborn (HDFN). It is desirable to replace the current donor‐derived anti‐D with a monoclonal antibody; however, the exact mechanism of IgG‐mediated suppression of red blood cell immune responses remains unclear. It has been proposed that the ability of anti‐D to prevent HDFN is due to IgG interactions with Fc receptors on phagocytic cells leading to rapid clearance of RhD+ red cells. Several monoclonal anti‐D alternatives have been developed with an emphasis on their ability to rapidly clear red blood cells from the circulation. None of the monoclonal antibodies have been as effective as donor‐derived anti‐D with some antibodies inadvertently leading to immune enhancement instead of inhibition. A better understanding of the mechanisms of IgG‐mediated inhibition of red cell alloimmunization is necessary. In this brief review, we highlight selected evidence for and against the requirement for rapid red cell clearance in the ability of IgG to prevent red cell alloimmunization. We also discuss potential alternative mechanisms which could be important for informing the future development of monoclonal antibody alternatives.
Source: ISBT Science Series - Category: Hematology Authors: Tags: Congress Review Source Type: research