Levels of paraoxonase, an index of antioxidant defense, in patients with active sarcoidosis

Oxidative mechanisms are currently discussed as playing a crucial role in the genesis of inflammatory lung diseases. We aimed to evaluate the oxidant-antioxidant balance in the pathogenesis and activity of sarcoidosis and to search if the change in the level of PON can be taken as an activity marker.

26 active sarcoidosis subjects aged 41.3+/-12.9 years, 37 inactive subjects aged 39.6+/-11.7 years and 48 control subjects aged 48.9+/-2.5 years were recruited in our study. Malondialdehyde (MDA), paraoxonase1 (PON1) and oxidized low density lipoprotein (oxLDL) levels in serum were analyzed by spectrophotometric, kinetic, and ELISA methods, respectively.

PON1 levels were significantly lower in the active disease state than both the inactive form and control groups. MDA levels were significantly higher in active sarcoidosis than both the inactive disease and control groups, and oxLDL levels were significantly higher in the active disease group than the inactive group and control group. The level of PON1 in the inactive disease group is not significantly different from the control group while the oxLDL and MDA levels of inactive group is significantly higher than the control group (p<0.001). There was a negative correlation between the PON1 activities and MDA values in both active and inactive groups (p=0.008).

Oxidative stress increases in sarcoidosis might be due to both increase in lipid peroxidation and decrease in antioxidant status (PON1) and the relationship between oxidative status and the activation of the disease should be discussed by comparing the previously known activation criteria.