A case report recently published in the Medical Journal Armed Forces India described a rare and clinically significant case of severe hemolytic disease of the fetus and newborn (HDFN) caused by a naturally occurring anti-Jkb antibody.
Researchers say it highlights the importance of detailed blood group testing in infants with early jaundice.
The case involved a full-term newborn with hyperbilirubinemia presenting within the first 24 hours of life. Doctors administered blood tests which showed the baby’s red blood cells were being destroyed. Further testing confirmed the presence of a rare antibody called anti-Jkb, part of the Kidd blood group system.
These antibodies are well known for their role in hemolytic transfusion reactions, but are rarely linked to HDFN. Even more unusual, the baby’s mother had never received a blood transfusion and had no previous pregnancies affected by this condition, suggesting the antibody formed naturally. Scientists believe such antibodies may sometimes develop after exposure to everyday environmental substances, such as bacteria, that resemble human blood antigens.
Learn more about HDFN causes and risk factors
A review of the literature identified only 15 reported cases of newborn illness caused by anti-Jkb antibodies worldwide in the last 60 years. Most were mild, but some were severe, and at least one was fatal. In this case, the antibody level was exceptionally high, and the baby showed clear signs of ongoing red blood cell breakdown.
Rather than proceeding directly to an exchange transfusion, doctors treated the infant with intensive light therapy and a single dose of intravenous immunoglobulin (IVIg). The infant responded well, with bilirubin levels stabilizing and then gradually declining, eliminating the need for exchange transfusion. The newborn was discharged in good condition by day five of life.
The study authors say this case serves as a reminder that careful blood testing is essential in babies with unexplained early jaundice and suggests that IVIg may be a valuable treatment option in severe cases.
“Prompt identification and aggressive medical management with IVIg can lead to excellent outcomes without resorting to invasive procedures like exchange transfusion,” they concluded.
Sign up here to get the latest news, perspectives, and information about HDFN sent directly to your inbox. Registration is free and only takes a minute.
