PB0455 - Enhanced expression of protease-activated receptor-1 and platelet and fibrin depositions in placenta accreta spectrum

Sunday, June 23, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

Murasaki Aman, MD, PhD

Assistant professor
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan

Co-Author(s)

Nobuyuki Oguri

medical stuff,　graduate student
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan
Toshihiro Gi

assistant professor
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan
Eriko Nakamura, MD, PhD

Clinical fellow
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan
SM

Sayaka Moriguchi Goto

assistant professor
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan
YS

Yuichiro Sato

Professor
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan
YA

Yujiro Asada

Doctor
Department of Pathology,Miyazaki medical association hospital
Miyazaki, Miyazaki, Japan
Atsushi Yamashita

professor
Department of Pathology, Faculty of Medicine, University of Miyazaki
Miyazaki, Miyazaki, Japan

Background: Placenta accreta spectrum (PAS) is characterized by invasion of placental villi in myometrium without intervening decidua, and is a cause of critical hemorrhage and maternal death. Protease-activated receptors (PARs) are activated by serine proteases such as thrombin, and PAR-1 induces cell proliferation or cell invasion in both tumor and non-neoplastic lesions. PAR-1 has been reported to be involved in placental development and pathogenesis of preeclampsia, however relationship between PAS and PAR-1 expression remains unknown.

Aims: We aimed to investigate the expression of PAR-1 and placental platelet and fibrin thrombus formation in human placentas with histologically diagnosed PAS.

Methods: We assessed clinicopathological factors and immunohistochemical expression of PAR-1 using an extent and intensity score in a series of 49 cases of PAS [superficial from, placenta accreta vera (PAV): 31, deep form, placenta increta (PI): 8, perforating form, placenta percreta (PP): 10] and 33 cases of control placenta. The immunopositive areas for platelet glycoprotein IIb/IIIa and fibrin was also measured.

Results: In the analysis of clinicopathological factors, in vitro fertilization was more frequent in the PAV group than other groups, while previous cesarean section was more frequent in the PI or PP group than other groups. PAR-1 expression was observed in cytotrophoblasts and syncytiotrophoblasts of placental villi in both control group and PAS. The PAR-1 expression score increased depending on the degree of invasion of placental villi, and the PAR-1 expression score was significantly higher in PP than that in PAV. The immunopositive areas for glycoprotein IIb/IIIa and fibrin in PAS were significantly larger than those in control group. Furthermore, the immunopositive areas for platelet and fibrin was significantly correlated with the PAR-1 expression score.

Conclusion(s): These results suggest that PAR-1 affect invasion of placental villi, and placental thrombogenic condition may affect PAR-1 activation.