Prevention of hemolytic disease of the fetus and newborn: what have we learned from animal models?

PURPOSE OF REVIEW: This review aims to highlight recent advances in our understanding of how anti-red blood cell (RBC) antibodies prevent erythrocyte immunization with an emphasis on new murine models.

RECENT FINDINGS: New murine models with clinically relevant human erythrocyte antigens have been used to understand the alloimmunization process and its inhibition. The search to elucidate the mechanism of action of IgG-mediated inhibition of erythrocyte alloimmunization has provided new evidence in support of a potential role for epitope masking, immune deviation and/or antigen modulation in this process. In addition, recent evidence suggests that blends of monoclonal antibodies targeting nonoverlapping epitopes on the RBC surface can improve the efficacy of monoclonal antibodies approaching that of polyclonal IgG.

SUMMARY: Animal models with defined alloantigens have helped to identify important mechanistic components that lead to alloimmunization and its inhibition by IgG. A better understanding of the underlying mechanisms leading to hemolytic disease of the fetus and newborn is required to develop the most effective prevention strategies for future patients.