(518) Lipoxins are correlated with inflammatory milieu in low-risk pregnancies

Endogenous lipoxins play a role in eliminating reactive oxygen species, inhibiting neutrophil chemotaxis, and decreasing both NF-kB and TNF- α. This mediator of systemic inflammation, inducible with aspirin, is not well described in literature regarding pro-inflammatory adverse pregnancy conditions. Our goal was to study lipoxins related to inflammatory milieu in healthy pregnancies.

Study Design:

This longitudinal cohort study recruited participants defined as low risk for pre-eclampsia per the United States Preventative Services Task Force (USPSTF) major criteria. Participants attended study visits each trimester.  Serum samples were obtained at two time points: 11-16 and 28-32 weeks’ gestation. Lipoxin (LXA₄) and C-reactive protein (CRP) in maternal plasma were quantified using Cayman Lipoxin A₄ ELISA kits (Ann Arbor, MI) and hsCRP protein enzyme immunoassay test kit (Foster City, CA), respectively. We utilized t-tests, paired t-test, and simple linear regression where appropriate.

Results:

56 participants were included. LXA₄ was highest in the first trimester and decreased mid-trimester. There was no correlation between LXA₄ concentration and maternal age, BMI, or parity at either pregnancy time point. A statistically significant inverse linear relationship between LXA₄ and CRP was present in the first trimester (P=0.04) and third trimester (P=0.0004) (Figures 1 & 2). Plasma LXA₄ concentration decreased between enrollment and the third trimester (termed Delta LXA4).  Delta LXA₄ and Delta CRP were compared, but this association was not statistically significant (P=0.91).

Conclusion: Lipoxins were not related to BMI or age in this low-risk cohort. The marked inverse relationship between CRP and LXA₄ suggests either reduced production or increased utilization in pro-inflammatory environments which may be a therapeutic target for aspirin prophylaxis.