Antibody-mediated glycophorin C coligation on K562 cells induces phosphatidylserine exposure and cell death in an atypical apoptotic process.

Background: Glycophorin C (GPC) is necessary in the maintenance of red blood cell structure. Severe autoimmune hemolytic anemia and hemolytic disease of the fetus and newborn (HDFN) have been associated with Gerbich (Ge) blood group system antigens expressed on GPC. Previous in vitro studies with cord blood progenitor cells have shown that anti-Ge suppresses erythropoiesis.

Predictive blood group genetics in hemolytic disease of the fetus and newborn: a 10-year review of a laboratory evaluation of amniotic fluid-derived DNA.

Objective: To identify the types of requests, the patterns of testing, and the error rates associated with the genetic identification of fetuses at risk for immune-mediated hemolytic disease.

Method: Retrospective review of the laboratory information system for all fetal blood group genotyping tests performed at Mount Sinai Hospital, Toronto, Canada from January 1997 to December 2006.

Results: Amniotic fluid-derived DNA, from 220 women (243 pregnancies), was tested for one or more antigens (279 tests) when the father was heterozygous for the inferred blood group antigen or was unavailable.

Fetal blood group genotyping.

Blood group genotyping using DNA extracted from fetal tissue is useful to identify fetuses at risk for hemolytic disease of the fetus and newborn (HDFN) due to maternal red cell alloantibodies. Four considerations are important for fetal blood group genotyping. First, paternal heterozygosity must be established, including tests that evaluate RHD hemizygosity.

Flow cytometric assessment of feto-maternal hemorrhage; a comparison with Betke-Kleihauer.

Objectives: Assessing the number of fetal cells in the maternal circulation quantifies the volume of feto-maternal hemorrhage, enhancing the ability to provide effective prevention of Rhesus (Rh) allommunization and appropriate fetal surveillance in cases of significant feto-maternal hemorrhage.

Methods: Having developed a standard curve with maternal samples spiked with known volumes of fetal red blood cells, we used a flow cytometric method using fluorescent labeled antihemoglobin F to quantitate fetal cells in the maternal circulatory system in two groups of women undergoing chorionic villus sampling (CVS), by either biopsy forceps or cannula aspiration (n = 170 women). We compared these results with the gold standard, the Betke-Kleihauer test.

Partial D, weak D types, and novel RHD alleles among 33,864 multiethnic patients: implications for anti-D alloimmunization and prevention.

Background: The D antigen includes category D, partial D, and weak D types, which are important because anti-D alloimmunization can occur in some but not all persons that express a variant RHD allele. At present, there is little prospective information on the prevalence of D variants among obstetric patients and potential transfusion recipients.

Study Design And Methods: The RHD alleles were prospectively examined in a large patient population identified on the basis of a difference in anti-D reactivity between two reagents.

Synonymous nucleotide substitutions in the neonatal Fc receptor.

The neonatal Fc receptor (FcRn) is a key receptor involved in the transcytosis of IgG across the maternal-fetal barrier. The level of IgG varies considerably among newborn infants. Since other Fc gamma receptors show single nucleotide functional variants, we determined whether common variant alleles exist for the FcRn.