A case of mild HDFN caused by anti-C, anti-D, and anti-G: Diagnostic strategy and clinical significance of distinguishing anti-G from anti-D and anti-C.

Anti-G is commonly present with anti-D and anti-C and can confuse serological investigations. The differentiation of anti-G from anti-D and anti-C is particularly essential for the accurate diagnosis of hemolytic disease of the fetus and newborn (HDFN) and appropriate administration of anti-D immunoglobulin prophylaxis in Rhesus (Rh) negative women. We reported a rare case of anti-G together with anti-D and anti-C in a pregnant woman and her female neonate. The titers of IgG anti-D, anti-C, and anti-G in the woman were 256, 128, and 32, respectively. While the titers of IgG anti-D, anti-C, and anti-G in the neonate were 16, 8, and 4, respectively. The neonate experienced mild HDFN and only received phototherapy during hospitalization. This report discusses the diagnostic strategy and clinical significance of differentiating anti-G from anti-D and anti-C.

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.

Lutheran.

The Lutheran blood group system consists of 19 antigens: four pairs of antithetical antigens--Lu(a)/Lu(b), Lu6/Lu9, Lu8/Lu14, and Au(a)/Au(b)--and 11 antigens of very high frequency. These antigens are located on four of the five immunoglobulin-like domains of both isoforms of the Lutheran glycoprotein. The LU gene is on chromosome 19 and comprises 15 exons. The two glycoprotein isoforms differ in the length of their cytoplasmic tails as a result of alternative splicing of intron 13. Lu(null) phenotype arises from homozygosity for inactivating mutations in the LU gene.The dominantly inherited Lu(mod) phenotype, In(Lu), results from heterozygosity for inactivating mutations in KLF1, the gene for the erythroid transcription binding factor EKLF. Clinically, antibodies of the Lutheran system are relatively benign. When hemolytic, they generally cause only mild, delayed hemolytic transfusion reactions or hemolytic disease of the fetus and newborn that can be treated by phototherapy. The Lutheran glycoproteins, which are members of the immunoglobulin superfamily of adhesion molecules and receptors, bind isoforms of laminin with alpha5 chains,components of the extracellular matrix abundant in vascular endothelia. The primary function of the Lutheran glycoproteins on RBCs could involve the transfer of maturing RBCs from the bone marrow to the peripheral circulation. They could also be involved in vascular occlusion and thrombotic events as complications of sickle cell disease and polycythemia vera, respectively.

[Immune cytopenias in newborns]. / Cytopénies immunes néonatales.

Rhesus D haemolytic disease of the newborn (RH HDN) and neonatal PlA1 alloimmune thrombocytopenia (NAT) are the main immune cytopenias affecting fetal red blood cells or platelets through maternal antibodies. During RH HDN, fetal anaemia and neonatal hyperbilirubinaemia may progress, if untreated, towards fetal death and neonatal kernicterus. Likewise, during NAT, intracranial haemorrhage may occur antenally, at delivery or postnatally. Fetal and neonatal transfusion therapy, pre-term delivery, and intensive phototherapy avoid or greatly reduce the incidence of these complications. However, the best treatment of RH HDN is to prevent primary anti-D immunisation in Rh negative pregnant women through passive immunotherapy with Rh immune globulin.