A newborn with hemolytic disease of the fetus and newborn (HDFN) due to Rh17 alloimmunizationAlloimmunization When a person’s immune system develops antibodies against foreign antigens from the same species—such as when an Rh-negative mother’s body forms antibodies against her baby’s Rh-positive red blood cells. was successfully treated with incompatible blood, according to a case report recently published in Pediatric Blood and Cancer.
Two genes encode the RhRh factor A protein or antigen found on red blood cells. When an Rh-negative mother carries an Rh-positive fetus, her immune system may make antibodies that attack the fetus' red blood cells. blood groupBlood group A classification of blood based on inherited markers found on red blood cells. The ABO and Rh blood groups are most common in HDFN., and the different possible rearrangements between these genes produce several Rh antigensAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens., of which the D, C, c and E antigens are the most significant.
The D- phenotype is a rare Rh presentation in which the person does not express any of the Rh antigens. Women with a D- phenotype can develop Rh17 alloimmunization during a first pregnancy, resulting in severe HDFN in subsequent pregnancies.
Learn more about HDFN treatment and care
The case involved a mother with a known AB D- blood group and an obstetric history of fetal death and early delivery. After 18 weeks of gestations, her obstetrician noticed fetal anomalies suggestive of HDFN; further testing confirmed the presence of anti-Rh17 antibodiesAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens..
Due to severe fetal anemiaAnemia A condition that occurs when the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues. In HDFN, anemia occurs when maternal antibodies destroy fetal red blood cells., the patients received several intrauterine transfusions and intravenous immunoglobulinIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus. (IVIGIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus.). However, due to persistent severe anemia as well as fluid accumulation in the pericardium and abdomen, the infant was delivered through an emergency C-section after 32 weeks of gestation.
The patient was immediately intubated, and lab workup revealed elevated bilirubinBilirubin A yellow substance produced when red blood cells break down. High bilirubin levels in newborns with HDFN can cause jaundice or, in severe cases, brain damage. levels, low hematocrit and low platelets. Despite intensive phototherapyPhototherapy A treatment that uses special blue light to help newborns break down bilirubin and prevent kernicterus., IVIG administration, and cryoprecipitate transfusion, the patient continued to deteriorate rapidly.
The center could not obtain Rh17 negative blood and therefore performed transfusions with O-negative blood; the patient received two exchange transfusions with incompatible blood before the Rh17 negative units arrived.
The patient showed improvement after the exchange transfusions and was discharged home with Epogen. The patient had severe hearing loss as a sequel of the HDFN complications but is currently otherwise healthy.
“The main aim in the initial postnatal period was to avoid sequelae of hemolysis while awaiting compatible blood units and resolution of antibodyAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens.- mediated RBC destruction,” the authors wrote.” Fortunately, despite the severity of her disease, she was able to survive with the help of a multidisciplinary team.”
