(P30-010-23) Does FPR2 Expression in Placental Extravillous Trophoblasts Vary by Pre-Eclampsia Diagnosis? A Preliminary Study

Objectives: The purpose of this study was to quantify FPR2 expression in placental tissue samples and correlate expression with inflammatory disease-states and maternal-fetal health outcomes.

Methods: Placental tissue samples were collected from both healthy and disease-state pregnancies (n=79) and stained for FPR2. FPR2 expression was quantified using QuPath digital analysis software to determine the percentages of low, medium, and high expression, and percent-positive detections. Mann-Whitney U tests were performed to compare FPR2 expression among placentas with and without pre-eclampsia and funisitis, as well as dichotomous birth outcomes such as mode of delivery. P-value < 0.05 was considered significant.

Results: The sample population of this study was composed of 11.4% pre-eclamptic vs 87.3% non-pre-eclamptic placental samples. There was no significant difference in total percent-positive detections of FPR2 observed in pre-eclamptic vs non-pre-eclamptic mothers (p=0.894). There was also no significant difference in percent-low, medium, and high expression between pre-eclampsia status (p=0.558, 0.760, 0.833). Similarly, no significant difference in low, medium, high, or total percent-positive detections was observed for placental funisitis diagnosis (p=0.317, 0.974, 0.232, 0.232). Percent-low FPR2 expression was significantly higher among C-section deliveries than vaginal deliveries (37.01% vs 31.97%, p=0.029).

Conclusions: The results of this study imply that placental FPR2 expression may not be crucial in the manifestation of diagnosed inflammatory diseases and comorbidities in maternal-infant pairs. Low incidence of pre-eclampsia in our sample, as well as the extremely low incidence of funisitis, may have impacted our results. The observed increase in percent-low FPR2 expression in cesarean deliveries may be explained by increased underlying inflammation prior to delivery, possibly stemming from the initial indication for cesarean delivery in those patients. Further investigation into FPR2 expression and indications for cesarean delivery including scheduled repeat and emergent c-sections, in addition to maternal-fetal indications based on infection status, is warranted to better understand the mechanism of FPR2 expression in placental trophoblast cells at parturition.

Funding Sources: CHRI and UNMC Dept. of Pathology