Blood group antigens other than the Rhesus (Rh) system, including Jk-b antibodies, have been shown to be a possible cause of hemolytic disease of the fetus and newborn (HDFN), according to findings from a case presentation recently published in the journal Cureus.
The study authors stated this case shows the significance of blood group antigens beyond the Rh system as a potential cause of HDFN.
In 1951, an antibody was detected in the sera of Mrs. Kidd—a woman whose child was experiencing symptoms of HDFN. The new antibody was ultimately named anti–Jk-a. In 1953, a new blood group antibody, termed anti–Jk-b, was identified.
The Kidd blood group is regarded as being of clinical importance, because Kidd antibodies have the potential to initiate both acute and delayed transfusion reactions, along with HDFN. The development of alloantibodies to Kidd antigens is fairly uncommon, with the triggering events including transfusion of blood/blood components, pregnancy, and transplantation.
Despite the rarity of alloantibodies to the Kidd antigens, however, the natural occurrence of anti–Jk-b antibodies in a voluntary blood donor has been reported.
In individuals with HDFN, maternal antibodies attack the fetal red blood cells (RBCs). Usually, these antibodies are linked to the development of alloimmunization due to incompatible blood groups between the mother and the fetus. In the mother, alloimmunization can be associated with transfusion or transplacental hemorrhage.
Learn more about HDFN causes and risk factors
The authors described a case of anti–Jk-b antibodies leading to the development of HDFN. At a gestational age of 37 weeks, four days, the patient described presented to the emergency department complaining of experiencing decreased fetal movements for six hours. Because she had gestational diabetes, the patient was receiving medical nutrition therapy. Her prior obstetric history included a normal vaginal delivery.
Based on the findings from a nonstress test, fetal distress was detected, and an emergency lower segment cesarean delivery was scheduled. Prior to the procedure, Ethylenediaminetetraacetic acid (EDTA) and clotted blood samples were obtained from the patient, and were sent to the blood center for blood grouping, typing, and cross-matching packed RBCs. The woman’s blood group was B RhD-positive; cross-matching was shown to be incompatible. Additionally, the results of an indirect Coombs test were positive, which was indicative of the presence of irregular antibodies in the mother’s serum.
At birth, the baby exhibited no physical signs of hydrops fetalis. Elevated bilirubin concentrations necessitated the use of high-intensity phototherapy for eight days in total. No bilirubin-related neurologic deficits were reported. The newborn was gaining weight well and was discharged home on day 10 of life.
“We regard routine antenatal screening as a crucial strategy to be implemented for every pregnant woman, regardless of her [RhD] phenotype,” they emphasized. “This proactive approach aims to identify [RBC] alloimmunization to other clinically significant blood group antigens[,] ensuring comprehensive prenatal care.”
