Complement Deposition in the Decidual Vasculature of Placentas
Sanjita Ravishankar, Jaya Sunkara, Lucia Wolgast. Montefiore Medical Center, Bronx, NY
Background: Pregnancy complications have an enormous impact on the health of the mother and the neonate. Histologic examination of the placenta of these patients often reveals characteristic findings that indicate chronic placental malperfusion, particularly decidual vasculopathy. However, the etiology of the vasculopathy as of yet cannot be readily determined. Pregnancy can be thought of as a model of immune regulation. Complement is an important element of the immune system that currently has a role in evaluation of antibody mediated rejection in transplant. This study aims to characterize the deposition of complement in the decidual vasculature (where activation and resulting thrombosis are the most likely to result in fetal harm) in a variety of pathologic pregnancies. We hypothesize that patients with pregnancy complications will have a greater degree of complement deposition in the decidual vasculature than normal controls.
Design: Paraffin embedded membranes from placentas delivered from 2009-2012 were collected to form a cohort of 26 women with normal and complicated pregnancies. The tissue was immunohistochemically stained with antibodies to C3d and C4d; clinical information was collected from the patients' charts. Degree of vascular staining was evaluated using the H-score method for percentage and intensity by a single blinded observer.
Results: Placentas from pregnancies complicated by intrauterine fetal demise or pre-eclampsia had a significantly higher H-score than normal controls, however the difference did not reach statistical significance in early spontaneous abortion and intrauterine growth restriction due to small sample size. Table 1 includes mean H-scores for each category examined, while Figure 1A demonstrates positive vascular C4d staining and 1B negative staining.