P-420 Pre-selected for an award: Uncomplicated oocyte donation pregnancies display elevated CD163 positive type 2 macrophage load in the decidua, which is associated with fetal-maternal HLA class II mismatches

AbstractStudy questionDo quantity and composition of decidual macrophages differ between uncomplicated oocyte donation (OD) pregnancies and non-OD in vitro fertilization (IVF) pregnancies?Summary answerOD placentas show higher decidual CD163 positive fraction within the total macrophage population compared to non-OD IVF placentas.What is known alreadyThe embryo of an OD pregnancy is completely allogeneic to the mother, which may lead to a bigger challenge for the maternal immune system to tolerize the fetus compared to autologous pregnancies. Placental macrophages may be essential in maintaining a healthy pregnancy. Macrophages can be classified into different categories based on phenotype and characteristics, in which type 2 macrophages are thought to exhibit immune suppressive activity.Study design, size, durationThis retrospective case-control study included patients who delivered in the Leiden University Medical Center between January 1st 2006 and July 1st 2016. A total of 42 pregnancies were enrolled in this study, conceived by uncomplicated singleton OD pregnancies (n  = 25) or non-OD IVF pregnancies (n = 17). Medical records were reviewed and clinical data were collected. Placental tissue samples were collected for immunohistochemical staining and blood samples were collected for HLA typing.Participants/materials, setting, methodsPlacentas were collected and immunohistochemically stained for CD14 (pan-macrophage marker) and CD163 (type 2 macrophage marker). The...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research