Aim Paraoxonase-1 (PON-1) is a calcium dependent glycoprotein enzyme that is found on the high density lipoprotein (HDL) in serum. PON-1 has been shown to protect low-density lipoprotein (LDL) and high-density lipoprotein (HDL) against oxidation and can reduce oxidative stres. In sepsis increases oxidative stres and decreases HDL concentrations. The aim of this study was to evaluate oxidant/anti-oxidant status in neonatal sepsis before and after therapy and to determine whether PON-1 could be used to monitor the treatment of neonatal sepsis.

Method Thirty-five patients with neonatal sepsis and 35 healthy controls were included in the study. PON-1 activities, total oxidant status (TOS), total anti-oxidant status (TAS) groups were measured and an oxidative stres index (OSI) was calculated.

Results Plasma levels of TOS, TAS and OSI were significantly higher in patients with neonatal sepsis before therapy as compared to after treatment (p<0.000, p<0.000 and p<0.000, respectively), plasma PON-1 level was significantly lower (p<0.000). Plasma levels of TOS, TAS and OSI were significantly higher in patients with neonatal sepsis before therapy as compared to the control group (p<0.000, p<0.000 and p<0.000, respectively) and plasma PON-1 level was significantly lower (p<0.000). TAS levels in after treatment were significantly higher than in the control group (p = 0.009), while TOS, OSI and PON-1 levels were similar in after treatment compared to control group (p = 0.0.078, p=0.597, p=0.086, respectively).