The rate of red blood cell (RBC) alloimmunization in the pediatric population in China and its implications for transfusion medicine and the risk of future hemolytic disease of the fetus and newborn (HDFN) has been recently reported in a study published in Transfusion Medicine and Hemotherapy.
Researchers gathered data from over 30,000 children treated in three major health centers in China. Results showed that 162 of them tested positive for antibodies targeting RBC antigens. The risk of having alloantibodies was higher between the ages of one and four and decreased after the fifth year of life. The authors also observed that girls were more likely to have alloantibodies than boys.
Learn more about HDFN testing and diagnosis
When the immune system enters into contact with a foreign molecule (antigen), it develops an immune response against it, often producing antibodies exclusively targeting the antigen in question. When this immune reaction occurs against the blood products (RBC, white blood cells (WBC), or platelets) of another human, it is called alloimmunization. The immune system has memory; this means that after each contact with the same antigen, the response against it will be stronger.
Alloimmunization is an issue in pregnancies where the mother has a different blood type than the fetus, which is the same as saying the fetus has different antigens in its RBC surface than the mother. In subsequent pregnancies, antibodies produced after alloimmunization can cause HDFN.
Transfusion medicine is another area where alloimmunization can represent a significant problem; a blood transfusion to an alloimmunized individual can lead to a transfusion reaction with severe health consequences for the patient.
Although the incidence of alloimmunization in adults has been investigated in several research papers, there is scarce information regarding alloimmunization in children. The authors stated that the presence of antibodies with high evanescence rates in the pediatric population suggests the “pressing need for nationwide shared transfusion records to avoid hemolytic transfusion reactions in children.”
“A better understanding of erythrocyte alloimmunization and autoimmunization in the pediatric population will help control the formation of alloantibodies and autoantibodies,” the authors wrote. “This control will mitigate the harm of hemolytic transfusion reactions, transfusion delay or HDFN in the children’s future.”
