Loss of Placental P-Glycoprotein May Be a Common Pathophysiologic Pathway for First Trimester Spontaneous Miscarriages.

A new interesting article has been published in Pediatr Dev Pathol. 2019 May 24:1093526619852874. doi: 10.1177/1093526619852874. and titled:

Loss of Placental P-Glycoprotein May Be a Common Pathophysiologic Pathway for First Trimester Spontaneous Miscarriages.

Authors of this article are:

Lanjewar S, Jayakumar R, Axiotis CA.

A summary of the article is shown below:

INTRODUCTION: P-glycoprotein the highly conserved mammalian adenosine triphosphate-binding cassette transmembrane multidrug protein transporter is involved in peri-implantation events and fetal placental development. Greater expression in early versus late pregnancy and localization in both syncytio- and cytotrophoblast indicate that P-glycoprotein transports substances across the uterine epithelium during early pregnancy and protects the conceptus from toxic substances during implantation and early embryogenesis. We hypothesized that P-glycoprotein is involved in the physiologic maintenance of early pregnancy and that P-glycoprotein dysregulation may be involved in early pregnancy pathologies.METHODS: First trimester dilation and curettage specimens were selected retrospectively from the archives of the Department of Pathology from spontaneous miscarriages (n = 36) and elective termination of pregnancy (n = 20). Two P-glycoprotein specific monoclonal antibodies JSB1and C219 were used on formalin-fixed, paraffin-embedded 5µ tissue sections. The location, intensity, and percentage of P-glycoprotein chorionic villous immunostaining were semiquantitated.RESULTS: Spontaneous miscarriages demonstrated absence or significant reduction in P-glycoprotein compared to elective terminations; 75% (27/36) showed total absence of P-glycoprotein, 19% (7/36) showed only rare villi with discontinuous immunostaining, and 6% (2/36) showed weak immunostaining. In contrast, 90% of elective terminations (18/20) showed positive immunostaining for P-glycoprotein and only 10% (2/20) showed loss of P-glycoprotein expression ( P < .0001).DISCUSSION: We report a dramatic loss/decrease of P-glycoprotein in first trimester spontaneous miscarriages. This finding in conjunction with the known high expression of P-glycoprotein in normal first trimester placental tissues suggests an important role of P-glycoprotein in the maintenance of early pregnancy.
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This article is a good source of information and a good way to become familiar with topics such as: P-glycoprotein; early pregnancy; first trimester spontaneous miscarriage; placental adenosine triphosphate-binding cassette transporters.