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

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.1063G>A. 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.

Hemolytic transfusion reaction attributable to anti-Dia.

CONCLUSIONS: In situations when a patient's antibody detection test is negative, many institutions have moved from an indirect antiglobulin test (IAT) crossmatch to an electronic crossmatch system. Here we report a case of an acute hemolytic transfusion reaction attributable to anti-Dia in a patient with a negative antibody detection test. A 22-year-old female patient with a diagnosis of ß thalassemia and sickle cell anemia commenced a routine exchange transfusion of 5 units of red blood cells (RBCs) in the apheresis unit as part of her regular treatment. When the patient started receiving the implicated unit, she reported back pain, chest pain, and a feeling of anxiety, suggestive of an acute transfusion reaction. The transfusion was ceased and an investigation of an adverse event was commenced. This case illustrates that the presence of antibodies to low-prevalence antigens remains a significant issue for transfusion-dependent individuals. To prevent other transfusion reactions by anti-Dia, the addition of Di(a+) cells to the reagent RBCs used for the antibody detection test along with IAT-crossmatching of donor units for all patients with sickle cell disease is recommended.