title: Paraoxonase 1 Activity and Survival in Sepsis Patients.
abstract: BACKGROUND
  Sepsis is a state of augmented oxidative stress and diminished antioxidant capacity. High density lipoprotein (HDL) particles were shown to possess antioxidant and anti-inflammatory properties, as well as Paraoxonase 1 (PON1), which is an enzyme that is also protective against HDL oxidation. Previous studies suggested a possible role of decreased PON1 activity or HDL levels in sepsis patients.
  
  
  OBJECTIVE
  The present study was designed to test a hypothesis that higher PON1 activity and HDL-cholesterol levels could predict a better survival in sepsis patients.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Venous blood samples were collected from sepsis patients for HDL-cholesterol levels, PON1 activity and cytokine assays (TNF-α and IL-6) and Acute Physiologic and Chronic Health Evaluation II (APACHE II) scores were calculated in order to weight patients' disease severity on the day of sepsis diagnosis. Patients were followed-up until the 28(th) day for any cause intra-hospital mortality. Data were statistically analyzed for effects of study parameters on patients' survival.
  
  
  RESULTS
  In total, 85 patients with sepsis were included in the study. The mean age was 65.2±17.9 years and 48 were male; at the end of the 28-day follow-up period, 46 survived. TNF-α (86.9±10.5 vs 118.6±16.4) and IL-6 levels (906.7±82.7 vs 1323.1±54.3) were significantly higher in non-survivors, while PON1 activity (140.7±42.3 vs 66.7±46.6) and HDL-cholesterol levels (43.6±8.1 vs 34.5±8.9) were significantly higher in survivors (p<0.001 for all). TNF-α (r=-0.763) and IL-6 levels (r=-0.947) showed strong negative correlations, PON1 activity (r=0.644) and HDL-cholesterol levels (r=0.477) showed positive correlations with patient survival (p<0.001 for all). Survival estimates significantly favored TNF-α (Log Rank 59.5, p<0.001) and IL-6 levels (Log Rank 53.2, p<0.001) according to PON1 activity (Log Rank 5.4, p<0.03) and HDL-cholesterol levels (Log Rank 8.3, p<0.005). Regression analyses for relative contributions of parameters to survival showed that higher IL-6 levels (t: -16.489, p<0.001) were the most significant negative factor for survival, and TNF-α levels (t: -4.417, p<0.001), whereas PON1 activity had a positive effect (t:3.210, p<0.003).
  
  
  CONCLUSIONS
  The present study showed that although low PON1 activity and HDL-cholesterol levels were related to mortality, higher levels were not found to be as predictive as cytokine levels for survival.
authors.affiliation: Department of Critical Care, Trakya University Faculty of Medicine, Edirne, Turkey.
authors.forename: Volkan
authors.initials: V
authors.lastname: İnal
authors.affiliation: Department of Critical Care, Gülhane Military Academy of Medicine, Ankara, Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Yamanel
authors.affiliation: Department of Critical Care, Gülhane Military Academy of Medicine, Ankara, Turkey.
authors.forename: Gürhan
authors.initials: G
authors.lastname: Taşkın
authors.affiliation: Department of Biochemistry, Gülhane Military Academy of Medicine, Ankara, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Tapan
authors.affiliation: Department of Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey.
authors.forename: Bilgin
authors.initials: B
authors.lastname: Cömert
keywords: Mortality; paraoxonase 1; sepsis