Circulating cytokines and alarmins associated with placental inflammation in high-risk pregnancies

Problem: Inflammation during pregnancy has devastating consequences for the placenta and fetus. These events are incompletely understood, thereby hampering screening and treatment. Method of study: The inflammatory profile of villous tissue was studied in pregnancies at high-risk of placental dysfunction and compared to uncomplicated pregnancies. The systemic inflammatory profile was assessed in matched maternal serum samples in cases of reduced fetal movements (RFM). Results: Placentas from RFM pregnancies had a unique inflammatory profile characterized by increased interleukin (IL)-1 receptor antagonist and decreased IL-10 expression, concomitant with increased numbers of placental macrophages. This aberrant cytokine profile was evident in maternal serum in RFM, as were increased levels of alarmins (uric acid, HMGB1, cell-free fetal DNA). Conclusion: This distinct inflammatory profile at the maternal-fetal interface, mirrored in maternal serum, could represent biomarkers of placental inflammation and could offer novel therapeutic options to protect the placenta and fetus from an adverse maternal environment.