Evaluation of paraoxonase and arylesterase activities in Egyptian patients with ankylosing spondylitis.

The role of paraoxonase (PON) and arylesterase (ARE) in the pathogenesis of inflammatory arthritis has been investigated, and their serum levels have been evaluated, but clinical study concerning PON1 and ARE and ankylosing spondylitis (AS) is little reported in literature. The aim of this study was to investigate PON1 and ARE activities in AS in comparison with healthy persons and their relation with the disease activity parameters. 35 AS patients and 35 healthy controls (matched for age and sex) participated. Disease activity of AS patients was assessed clinically according to the Bath AS disease activity index, and AS functional impairment was assessed using the Bath AS Functional Index. Serum samples were collected from all subjects to evaluate serum PON1, ARE activities, and lipid profile. The mean serum triglycerides, total cholesterol, and low density lipoprotein (LDL) were significantly higher in the AS patients than in controls, while the high-density lipoprotein (HDL) is significantly lower in the AS patients than controls. Serum PON1 and ARE activities were significantly lower in AS patients than in controls, while malondialdehyde (MDA) was significantly higher. AS patients with active disease had significantly higher serum triglycerides, total cholesterol, LDL and MDA while lower HDL, PON1 and ARE than those with no active AS. Decrease in the PON1/ARE activity leading to generation of oxidative stress may play an important role in the pathogenesis of AS. Moreover, it seems that activity of PON1/ARE in patients with AS is strictly correlated with the activity of the inflammatory process.