title: OS098. Increased adiposity decreases the intensity myeloperoxidase in neutrophils from pregnant women at delivery.
abstract: BACKGROUND
  The cardiovascular risk factor myeloperoxidase (MPO) is a lysozomal enzyme found within azurophillic granules of inflammatory cells. Upon activation, inflammatory cells degranulate and release MPO. In the pregnancy disorder preeclampsia, MPO is elevated in the circulation and placenta and greater numbers of neutrophils are positive for hydrogen peroxide.
  
  
  OBJECTIVE
  To determine if during preeclampsia, increases in circulating MPO result in losses of intracellular MPO within neutrophils. We also sought to determine if the degree by which neutrophil functionand intracellular MPO levels varies by BMI differsin women with preeclampsia compared to normal control pregnancies.
  
  
  METHODS
  Reactive oxygen species (nitric oxide, superoxide and hydrogen preoxide) weredetermined in fresh whole blood samples from non-smoking women with normal pregnancies (n=8) and preeclampsia (n=9) by flow cytometry using intracellular fluorescent probes. Granulocytes were permeabilized (Dako, Glostrup, Denmark) and stained for MPO (anti-MPO, BD, San Jose, CA), and the number and percentage of CD15 and MPO positive cells and the intensity of MPO staining (MFI) was determined by flow cytometry. Student t-test or one-way ANOVA was used to test for significance. Dataare reported as mean±sem.
  
  
  RESULTS
  There wasno significant difference in the number (percentage) orintensity of neutrophils staining for MPO between normal pregnancies and preeclampsia (MPO positive cells: 2816±981(39% positive) vs 2714±901(28% positive), Intensity: 3337±434 vs 3178±367 MFI units). However, there was a dramatic reduction in intensity of MPO staining in neutrophils from overweight women (BMI>27) compared to normal weight women regardless of pregnancy outcome (2508±160 vs 4091±376 MFI units, p=0.001). Among normal pregnancies, lean women had significantly more MFI of MPO than overweight women (4500±750 vs 2639±178 MFI units, p=0.04). The same trend was seen among women with preeclampsia (lean; 3845±428 vs overweight; 2344±292MFI units, p=0.07).
  
  
  CONCLUSIONS
  The increased circulating levels of MPO in preeclampsia did not result in decreased intensity of MPO staining in circulating neutrophils. Neutrophils from normal weight women have greater amounts of intracellular MPO available upon activation than overweight and obese women.
  This project was supported byNational Institutes of Health grant PO1-HD30367.
authors.affiliation: Environmental and Occupational Health and Obstet. Gyn and Repro Sciences, Magee Womens Research Institute & University of Pittsburgh, Pittsburgh, United States.
authors.forename: R E
authors.initials: RE
authors.lastname: Gandley
authors.affiliation: Magee Womens Research Institute, Pittsburgh, United States.
authors.forename: S
authors.initials: S
authors.lastname: McGonigal
authors.affiliation: Magee Womens Research Institute, Pittsburgh, United States.
authors.forename: V
authors.initials: V
authors.lastname: Carroll
authors.affiliation: Obstetrics, Gynecology and Reproductive Sciences, Magee Womens Research Institute, Pittsburgh, United States.
authors.forename: A
authors.initials: A
authors.lastname: Jeyabalan