Inflammatory markers are elevated in early pregnancy, but not late pregnancy, in womenwith overweight and obesity that later develop preeclampsia

Problem: Obesity and preeclampsia both involve a pathological inflammatory response, which may be how obesity increases preeclampsia risk. Previous studies have failed to assess robust measurements of inflammatory markers across gestation, specifically in overweight/ obese women in the context of preeclampsia. Method of study: We measured 20 inflammatory markers in plasma via multiplex assay (ThermoFisher Inflammation 20 plex Human ProcartaPlex Panel) across the three trimesters of pregnancy in an existing cohort of overweight and obese women who developed preeclampsia (n = 37) and without preeclampsia (n = 74). Mann-Whitney U tests examined differences in inflammatory marker concentrations between cases and controls. Repeated measures ANOVA tests were used to explore differences in inflammatory marker concentrations over time within cases and controls. Results: Pro-inflammatory markers (IL-1 alpha, IL-1 beta, IL-6, IFN-alpha, IFN-gamma, GM-CSF, IL-12p70, IL-17 alpha, TNF-alpha, IL-8) and anti-inflammatory markers (IL-4, IL-10, IL-13) were higher in the first and second trimester in participants who later developed preeclampsia compared to thosewho did not (p<.05). OnlyTNF-alpha and IL-8 remained elevated in the third trimester. Inflammatory markers did not change across pregnancy in preeclampsia cases but did increase across pregnancy in controls. Conclusion: Our findings diverge from prior studies, predominantly of non-obese women, that report lower circulating concentrations of anti-inflammatory cytokines in preeclampsia versus normotensive pregnancy, particularly by late pregnancy. We posit that women with overweight and obesity who develop preeclampsia entered pregnancy with a heightened pro-inflammatory state likely related to obesity, which increased risk for preeclampsia. Further studies are needed to investigate if inflammatory maker profiles differ between obese and non-obese women.