Placental transfer of antibodies in man

Leptin increases maternal investment

The primary goal of virtually all organisms is to produce genetic offspring, thereby passing on their genes to future generations. Offspring production, however, is limited by available resources within an environment. Moreover, distributing sufficient energy among competing physiological systems is challenging and can result in trade-offs between self-maintenance and offspring investment when resources are limited. In the current study, we tested the hypothesis that the adipose hormone leptin is involved in mediating energetic trade-offs between competing physiological systems. Specifically, we tested the effects of elevated maternal leptin on investment into offspring production versus self maintenance (immune function), in the Siberian hamster (Phodopus sungorus). The current study provides the first evidence that leptin serves as a signal to mothers of available energy resulting in epigenetic effects. Therefore, elevated leptin allows females to retain more embryos to parturition, and rear more offspring to weaning via reduced maternal infanticide. Innate immune response was suppressed seemingly as a result of these enlarged litters, suggesting that the observed fitness increase is not without costs to the mother. Collectively, these findings suggest that leptin plays a critical role in allowing mothers to determine how much energy to invest in the production and care of young versus self-maintenance.

Human placental Fc gamma-binding proteins in the maternofetal transfer of IgG

Annexin II, a member of the annexin family of Ca2+ and phospholipid binding proteins, is present in human placenta. Placental annexin II has low affinity FcR activity, and is present as a heterotetramere on syncytiotrophoblast apical cell membrane extracellular surface. In addition to annexin II, transmembraneous leukocyte FcRIII is present on syncytiotrophoblast apical membrane. Either one, or both molecules may mediate the binding of IgG and thereby facilitate its transport through the syncytiotrophoblast layer. However, the presence of other maternal plasma proteins in syncytiotrophoblasts that are not transported to the human fetus is suggestive of nonspecific fluid phase endocytosis. The MHC class I like FcR, similar to the receptor found in neonatal rodent intestine, FcRn, is present intracellularly in human syncytiotrophoblasts, as is its light chain beta 2-microglobulin. The hFcRn is not detected on the apical plasma membrane. The placental hFcRn co-localizes with IgG in syncytiotrophoblast granules. It is likely that hFcRn binds and transcytoses IgG through the syncytiotrophoblast. Protected transfer of IgG may occur within syncytiotrophoblast endocytotic vesicles prior to release in the villous stroma and subsequent translocation into the lumen of fetal stem vessels by uptake and transport in endothelial caveolae.

High-dose intravenous IgG for the treatment of severe rhesus alloimmunization

The value of intravenous immunoglobulin (IVIG) in the treatment of 24 severely Rh-sensitized pregnant women was studied. IVIG was infused at a daily dose of 0.4 g/kg maternal body weight for 4-5 consecutive days, and was administered again 15-21 days later until delivery, depending on the evolution of the hemolytic disease. Our population was divided into 3 groups according to the time of onset of therapy: group 1 (n = 8), before 20 weeks' gestation; group 2 (n = 7), 20-28 weeks, and group 3 (n = 9), after 28 weeks. Initial mean anti-D level was significantly higher in group 1 (25.9 +/- 12.9 IU/ml) than in the other 2 groups, whose mean values were, however, higher than 10 IU/ml. Amniotic-fluid total bilirubin levels before the onset of therapy were pathologic, and in 55% of the cases they coincided with zone 3 of Liley's chart. Hydrops fetalis at the onset of treatment accounted for the only 3 fetal deaths in groups 1 and 2. None of the fetuses developed hydrops during treatment. Six of the 9 neonates in group 3 were depressed at birth (1-min Apgar below 7). However, at 5 min only 1 newborn showed an Apgar below 7. Mean birth weight was over 2,500 g in all the cases. Neonatal hematological condition in group 2 (50% of the babies required only phototherapy) was better than in the other 2 groups (transfusional therapy). There was a significant fall in maternal anti-D titers and intrauterine hemolysis after IVIG treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial occurrence of hemolytic disease of the newborn due to AO blood group incompatibility

The extent of the familial occurrence of hemolytic disease of the newborn due to AO blood group incompatibility between mother and fetus was examined. The records of all families in which the mother had blood group O and two or more babies had blood group A, with one of them having been born at Women & Infants Hospital of Rhode Island in the index year of 1979, were examined. Eighty-nine of these families fulfilled criteria intended to exclude causes of hyperbilirubinemia other than AO blood group incompatibility. The peak bilirubin level in each infant was graded as normal, elevated, or severely elevated. The relations between birth order and peak bilirubin level, between peak bilirubin levels in the first and second babies in each family, and between gestational age and peak bilirubin level were assessed. The first two of these relations showed effects at the 0.10 and 0.05 significance levels, respectively. It is concluded that the risk of hyperbilirubinemia attributable to AO blood group incompatibility is greater for the second than for the first baby at risk in a sibship, that the risk is yet greater for the second if the first was also affected, and that, in the latter case, there is also increased risk of marked hyperbilirubinemia.

Small dose anti-Rh therapy after first trimester abortion

The standard prophylactic dose of anti-Rh immunoglobulin used in the United States is 300 microgram. For use after spontaneous or induced abortion and diagnostic amniocentesis, this dose represents immunological "overkill". A 50 microgram dose has been effectively used for these patients in other countries but the specific products used were not equivalent to the products available in the USA. No evaluation of this 50 microgram dose has been conducted in the USA. This is a pilot study of 315 patients given a 50 microgram dose or a 300 microgram dose of anti-Rh immunoglobulin after first trimester abortion. No patient in either treatment group developed atypical blood group antibodies within 6 months. This finding confirms that 50 microgram of the American product is protective after first trimester abortion.

Binding to specific receptors on oocyte plasma membranes by serum phosvitin-lipovitellin

Specific binding sites for the serum complex of phosvitin and lipovitellin have been shown to exist on the outer surface of rapidly growing chicken oocytes. The existence and specificity of these sites were demonstrated by competition for binding to unfixed oocyte membrane fragments and by displacement of already bound and labeled phosvitin-lipovitellin from formaldehyde-fixed membranes. Only unlabeled phosvitin-lipovitellin competed with the 125I-labeled complex for binding to the fragments of displacement of bound label; IgG isolated from egg yolks and bovine serum albumin were ineffective.