Anti‐D in a mother, hemizygous for the variant RHD*DNB RHD*DNB gene, associated with hemolytic disease of the fetus and newborn

摘要

BACKGROUND Individuals with the partial D phenotype when exposed to D+ red blood cells (RBCs) carrying the epitopes they lack may develop anti‐D specific for the missing epitopes. DNB is the most common partial D in Caucasians and the clinical significance for anti‐D in these individuals is unknown. STUDY DESIGN AND METHODS This article describes the serologic genotyping results and clinical manifestations in two group D+ babies of a mother presenting as group O, D+ with alloanti‐D. RESULTS The mother was hemizygous for RHD*DNB gene and sequencing confirmed a single‐nucleotide change at c.1063GA. One baby (group A, D+) displayed bilirubinemia at birth with a normal hemoglobin level. Anti‐A and anti‐D were eluted from the RBCs. For the next ongoing pregnancy, the anti‐D titer increased from 32 to 256. On delivery the baby typed group O and anti‐D was eluted from the RBCs. This baby at birth exhibited anemia, reticulocytosis, and hyperbilirubinemia requiring intensive phototherapy treatment from Day 0 to Day?9 after birth and was discharged on Day 13. Intravenous immunoglobulin was also administered. Both babies were heterozygous for RHD and RHD*DNB . CONCLUSION The anti‐D produced by this woman with partial D DNB resulted in a case of hemolytic disease of the fetus and newborn (HDFN) requiring intensive treatment in the perinatal period. Anti‐D formed by women with the partial D DNB phenotype has the potential to cause HDFN where the fetus is D+. Women carrying RHD*DNB should be offered appropriate prophylactic anti‐D and be transfused with D– RBCs if not already alloimmunized.