Increased RBC autoantibody production in pregnancy.

BACKGROUND: Autoimmunization against RBCs is generally believed to occur very rarely during pregnancy and to represent a high risk for those affected. The occurrence of benign RBC autoantibodies in pregnancy is reported. STUDY DESIGN AND METHODS: The incidence of autoantibodies to RBCs in unselected pregnant and nonpregnant women were compared by the new standard gel hemagglutination method. RESULTS: Data from a total of 22,782 pregnant and 12,903 nonpregnant women were analyzed. The antibody screen test was positive in 547 (2.40%) of the pregnant women. The positive test results were related to passive anti-D in 341 cases (1.50%), to clinically relevant alloantibodies in 43 cases (0.19%), to clinically irrelevant antibodies in 138 cases (0.61%), to autoantibodies in 23 cases (0.1%), and to autoantibodies plus alloantibodies in 2 cases (0.01%). In the cases of alloantibodies and/or autoantibodies, the DAT was invariably positive with anti-C3d and less commonly so with anti-IgG. The autoantibodies were first detected during pregnancy, they predominantly reacted with enzyme-treated RBCs, and none of the affected women or their infants appear to have developed clinically significant hemolysis. In the control group consisting of nonpregnant female blood donors, there were 3 cases (0.02%) of clinically insignificant IgG autoantibodies. CONCLUSION: There is an increase in autoimmunization against RBCs during pregnancy. The resultant autoantibodies do not appear to cause significant RBC destruction. Further studies are required for precise characterization of this phenomenon.

Expression of the oxytocin receptor in relation to steroid receptors in the uterus of a primate model, the marmoset monkey.

The dynamics of the receptors for oestrogen (ER), progesterone (PR) and oxytocin (OTR) in the marmoset uterus have been analysed throughout the entire cycle and early pregnancy. Uteri obtained during the early, mid/late and late proliferative phase, and the early, mid and late secretory phase and early pregnancy were examined by immunohistochemistry (OTR, ER, PR) and autoradiography (OTR). A massive upregulation of the ER in the cell nuclei of glandular epithelium and stromal cells during the mid proliferative phase was succeeded by a declining staining intensity and positively stained cell number in the secretory phase. PR immunoreactivity increased in the late proliferative phase and early secretory phase, mainly within the cell nuclei, and then declined in both intensity and cell number towards the mid to late secretory phase. Myometrium showed a similar staining pattern for the steroid receptors. OTR were expressed weakly in stroma throughout the entire cycle, increasing slightly in the secretory phase. Glandular epithelium showed positive staining only during the periovulatory period. Myometrial OTR expression was weak during the proliferative phase, increased towards the secretory phase, and was maximal in the late secretory phase. Myometrial tissue adjacent to endometrium was most strongly stained. A cyclic shift evidently occurred in the pattern of steroid receptors, perhaps reflecting the steroid environment or the luteinizing hormone increase associated with ovulation.