Association of serum amyloid A and oxidative stress with paraoxonase 1 in sarcoidosis patients

Background It has been reported that high‐density lipoprotein ( HDL ) particles have anti‐inflammatory and antioxidant roles thanks to different enzymes such as paraoxonase 1 ( PON 1). Under inflammatory and oxidative stress conditions, HDL particles may lose their protective properties. Sarcoidosis is an inflammatory disease characterized by excessive oxidative stress. Serum amyloid A ( SAA ) is produced in liver and in granulomas, and its concentration increases in inflammatory conditions contributing to increased catabolism of HDL particles. The aim of our study was to determine PON 1 activity, SAA concentration and their associations in patients with sarcoidosis. Materials and methods Inflammatory [high‐sensitive C‐reactive protein (hs CRP ), angiotensin‐converting enzyme ( ACE ), SAA ], lipid [total cholesterol ( TC ), HDL ‐cholesterol ( HDL ‐c), low‐density lipoprotein cholesterol ( LDL ‐c), triglycerides ( TG )] oxidative stress status parameters [total oxidant status ( TOS ), malondialdehyde ( MDA ), pro‐oxidant–antioxidant balance ( PAB ), sulfhydryl ( SH ) groups] and PON 1 activities were determined in serum of 72 patients with sarcoidosis and 62 healthy subjects. Results Hs CRP ( P < 0·05), TC , LDL ‐c, TG , SAA , TOS , MDA and PAB ( P < 0·001) were significantly higher, whereas HDL ‐c, SH groups and PON 1 activity ( P < 0·001) were significantly lower in patients with sarcoidosis when compared with controls. PON 1 showed significant association with SAA , MDA and PAB . It was shown that 71% of decrease in PON 1 activity may be explained by increase in TOS , PAB and SAA concentration. Conclusions We found decreased PON 1 activity and increased SAA concentration in patients with sarcoidosis. Inflammatory condition presented by high SAA was implicated in impaired HDL functionality evident through dysregulated PON 1 activity. Excessive oxidative stress was also involved in dysregulation of PON 1 activity.