Hemolytic Disease in Newborn Due to Jka Antibody: A Unique Clinical Presentation

Hemolytic disease in newborn results from alloimmune-mediated destruction of fetal or neonatal red blood cells caused by maternal alloantibodies. While ABO and Rh (D) incompatibilities are common causes, other minor antigenic mismatches such as Kidd are relatively infrequent. Here, we report a case of a female infant displaying conjugated hyperbilirubinemia and hepato-splenomegaly. Lab tests revealed both mother’s and baby’s blood groups as A positive, along with elevated reticulocyte count and a positive direct antiglobulin test. An abdominal ultrasound unveiled inspissated bile syndrome, likely due to calcium bilirubin sludge, leading to the conjugated hyperbilirubinemia. Further assessment revealed the infant and the father had a JKa-positive RBC phenotype, while the mother had a JKa-negative phenotype. This case highlights the significance of blood group antigen beyond the Rh system as a potential cause of hemolytic disease in newborn.