Anti-trophoblast antibody responses during normal human pregnancy

During the course of a normal uncomplicated human pregnancy the mother generates an antibody response directed against determinants present on the plasma membrane of the outer fetal layer of the term placenta, the syncytiotrophoblast. The response, measured by an ELISA that utilises syncytiotrophoblast plasma membrane as the antigenic target, is predominantly IgG in nature, but with a minor contribution from IgM molecules. Maximum responses were observed during the first trimester and the levels gradually declined as the pregnancy progressed. On a population basis, this antibody response profile was mainly restricted to first and second pregnancies, although anti-trophoblast antibody responses could be detected in multiparous women but with a greatly reduced incidence compared with primipara. Mechanisms to account for these observations are discussed. Throughout, the anti-trophoblast antibody levels detected in pregnancy sera were compared with the background levels which were observed in sera obtained from males and nulliparous non-pregnant females.     

Anti-M antibody in pregnancy

Our three cases represent the spectrum of findings when maternal anti-M is present. In the first case, the father's genetic makeup (NN) indicated no disease would occur. In the second case, despite antibody capable of crossing the placenta, the infant did not become sick. In the third case, hemolytic anemia required transfusion of the newborn, despite a negative direct Coombs' (DAT). In summary, anti-M antibody is an uncommon cause of hemolytic disease of the newborn. When anti-M, IgG optimally reactive at 37 degrees C, is identified in the maternal blood, the paternal blood must be checked for the presence of M antigen. If the father has M antigen the fetus may be at risk. Since there is no documented body of experience that titers of anti-M predict severity of disease, our recommendation is that amniotic fluid bilirubin studies be done, in spite of the fact that only one prior case of hemolytic disease due to anti-M was found reported from the United States. Anti-M is an unpredictable antibody and serial antibody titers are not reliable. After delivery the infant's MN antigen status should be determined, because a negative direct Coombs' test may be found even when M antigen is present in the infant and hemolysis is occurring. Further studies are needed to determine the clinical impact of anti-M antibody on unrecognized hemolytic disease of the newborn.     

Syncytin-2 mRNA及其受体MFSD2 mRNA在正常妊娠及子痫前期胎盘组织中的表达研究

目的检测syncytin-2 mRNA及其受体MFSD2 mRNA在正常妊娠及子痫前期胎盘组织中的表达及其与子痫前期发病的关系。 方法分析2010年3月至2011年12月就诊于广州医学院第三附属医院住院分娩46例孕妇资料,正常妊娠组(21例),子痫前期组(25例)。在剖宫产术中采集产妇胎盘组织,采用实时荧光定量PCR法检测胎盘组织中syncytin-2 mRNA及其受体MFSD2 mRNA的表达,两组表达水平的比较采用t检验。 结果Syncytin-2 mRNA及其受体MFSD2 mRNA在正常妊娠组及子痫前期组患者胎盘组织中均有表达。在子痫前期组,两种指标分别为5.59±0.29和0.79±0.08;在正常妊娠组,两种指标分别为6.99±0.62和0.83±0.10。两组中,syncytin-2 mRNA表达水平差异有统计学意义(t＝2.331,P＝0.029),MFSD2 mRNA表达水平差异无统计学意义(t＝0.258,P＝0.778)。 结论胎盘组织syncytin2 mRNA表达下调可能与子痫前期发病密切相关,其受体MFSD2 mRNA与子痫前期发生无相关性。     

T cells in normal pregnancy and recurrent pregnancy loss

This review focuses on the possible role of T cells in successful pregnancy and in unexplained recurrent abortion. The functions exhibited by Th1 and Th2 cells have suggested, perhaps in a simplistic way, that Th1-type cytokines, which promote allograft rejection, may compromise pregnancy, whereas the Th2-type cytokines, by inhibiting Th1 responses, promote allograft tolerance and therefore may improve fetal survival. However, Th1 cytokines are not always detrimental for pregnancy development. Th1 cytokines, depending on their time of expression, stage of gestation and relative concentrations, could have a positive role in successful pregnancy. Other cytokines (LIF, M-CSF) produced by T cells seem to be important for the maintenance of pregnancy. Hormones present in the microenvironment of the decidual T cells could be responsible, at least in part, for the cytokine profile of the T cells. Indeed, progesterone is a potent inducer of Th2-type cytokines (e.g. IL-4 and IL-5), LIF and M-CSF production by T cells, whereas relaxin induces T cells to produce IFNgamma. Of course, the success of pregnancy depends on many mechanisms induced by different type of cells. Th2 cells could be one of these.     

Ketonuria in normal pregnancy

Nine low-risk, clinically normal pregnant women tested their urine for ketone bodies at three- to four-day intervals throughout gestation. Eight of the women had acetoacetonuria present on two to 15 days each. This finding was not related to length of gestation or time of day. Ketonuria probably occurs sporadically in most normal pregnancies.     

Placental tissue cyclo-oxygenase 1 and 2 in pre-eclamptic and normal pregnancy.

OBJECTIVE: To investigate the activities of the 2 isoforms of prostaglandin synthetic enzyme cyclo-oxygenase (COX), COX-1 and COX-2, in the placental tissue of women with pre-eclampsia and healthy pregnant women. The relationship between placental lipid peroxidation and the activities of COX-1 and COX-2 was also investigated. METHODS: Tissue specimens were obtained from pre-eclamptic women (20 had severe pre-eclampsia and 38 had mild pre-eclampsia) and 27 healthy pregnant women who underwent cesarean section before the onset of labor. Malondialdehyde (MDA) levels and COX-1 and COX-2 activities were measured in placental tissue homogenates. RESULTS: Mean activities for COX-1 and COX-2 were significantly lower in women with severe pre-eclampsia than in healthy controls (P<0.05 and P<0.01, respectively). COX-1 and COX-2 activities were also lower in women with mild pre-eclampsia than in healthy controls, but the difference was of borderline significance (P=0.049 and P=0.059, respectively). The mean placental MDA level was significantly higher in pregnant women with severe and mild pre-eclampsia than in healthy pregnant women (P<0.01 for both). The correlation analysis showed significant negative correlations between MDA and COX-1 (r=-0.44, P<0.001) and MDA and COX-2 (r=-0.45, P<0.001) in the placental tissue of women with pre-eclampsia. CONCLUSION: These results suggest that COX-1 and COX-2 activities are decreased in the placental tissue of women with pre-eclampsia, probably by oxidative stress.     

Haemostasis in normal and abnormal pregnancy

Haemostasis is a complex and dynamic equilibrium involving pro-coagulants, the natural anticoagulation system and fibrinolysis. Normal human pregnancy is associated with profound alterations to the process of haemostasis such that the pro-coagulant effect becomes dominant. There are very few studies which have attempted to elucidate the adaptations that take place in the uteroplacental circulation where the haemostatic system faces the conflicting tasks of maintaining blood fluidity during pregnancy while preparing for the haemostatic challenge of delivery. It is hypothesised that excessive thrombosis within the uteroplacental circulation provides the mechanistic basis for the reported associations between the inherited thrombophilias and major pregnancy complications. The evidence underpinning this widely quoted hypothesis is weak.     

Glycohemoglobins in normal and diabetic pregnancy

Glycosylated hemoglobin (HbA1) concentration was measured in 155 pre- and 30 postpartum patients to study its correlation with glucose metabolism and perinatal outcome in patients suspected of carbohydrate intolerance during pregnancy. Though the mean HbA1 values were significantly higher in gestational diabetics compared to normal pregnant controls, the large overlap between HbA1 levels of diabetic patients and levels in the of normal range, make HbA1 an unreliable screening device for diabetes. However, if the HbA1 level was elevated in patients suspected of carbohydrate intolerance, but who had a normal glucose tolerance test, the perinatal outcome in terms of macrosomia and neonatal metabolic abnormalities was similar to that of the group with gestational diabetes. HbA1 measurements should be obtained in these women, and, if elevated, maternal and fetal surveillance is recommended. HbA1 level is not a useful predictor of birthweight, though may be of value as a postpartum screen for unrecognized diabetes and may help discriminate between a constitutionally large but otherwise normal newborn and a large infant of a diabetic mother.     

Syncytin及其受体ASCT2 mRNA在正常妊娠和子痫前期胎盘中的表达

目的研究人内源性逆转录病毒的膜糖蛋白syncytin及其受体ASCT2 mRNA在正常妊娠和子痫前期胎盘中的表达差异。方法应用实时定量RT-PCR测定正常妊娠晚期胎盘组织（11例）和子痫前期胎盘组织（11例）中syncytin及其受体ASCT2 mRNA的相对表达量。结果syncytin mRNA在两组中均有表达，其在子痫前期胎盘的表达明显低于正常妊娠晚期胎盘的表达（P=0．0024）。ASCT2 mRNA在两组中表达差异无显著性（P=0．1877）。结论syncytin mRNA表达下降，可能与子痫前期的病因及病理生理有关。