Hemolytic Disease of the Newborn Caused by Anti-Cellano (Anti-k) Alloimmunization: A Case Report

This report describes a rare case of hemolytic disease of the newborn caused by anti-Cellano (anti-k) antibodies, part of the clinically significant Kell blood group system, the third most important blood group system after ABO and Rh. We present the case of a 43-year-old woman with a history of multiple miscarriages and one previous live birth conceived through in vitro fertilization with a donor oocyte. At 38 weeks of gestation, she delivered a B-positive neonate who subsequently developed anemia and jaundice. Laboratory evaluation demonstrated a positive direct Coombs test and the presence of anti-k antibodies in the mother, confirming the diagnosis. Initial management included intensive phototherapy, intravenous immunoglobulin, erythropoietin, and iron supplementation. Despite supportive therapy, hemoglobin levels progressively declined, and red blood cell transfusions became necessary. Because compatible k-negative donor units were not readily available, the mother, confirmed to be k-negative, donated blood for transfusion, resulting in clinical and hematologic improvement. This case highlights the importance of recognizing rare blood group incompatibilities and performing comprehensive immunohematologic evaluation in neonates with unexplained hemolysis.