Relationship between lipid peroxidation and disease activity in patients with Behçet's disease

Abstract

Behçet's disease is a chronic multi-systemic disorder which is characterized by a relapsing systemic inflammatory process. The alteration of lipid profile and lipid peroxidation resulting from the inflammatory process may be associated with an increased risk for atherosclerosis in patients with Behçet's disease. We investigated lipids, lipoprotein and lipid peroxidation and their inter-relationships considering the disease activity. Eighteen patients (11 male and 7 female) and 20 age-matched healthy subjects (10 male and 10 female) were studied. Lipid profile including total cholesterol, triacylglycerol, HDL-cholesterol, LDL-cholesterol, lipoprotein(a), apoAI and apoB, and acute phase reactants including polymorphonuclear (PMN) elastase, PMN leukocyte count, erythrocyte sedimentation rate (ESR) and complements (C₃, C₄) were evaluated in patients in active and inactive periods of Behçet's disease and control subjects. The levels of thiobarbituric acid reactive substance (TBARS) were assessed as an indicator of lipid peroxidation. Lipid peroxidation was found to be increased in the active period compared to the inactive period of the disease and control subjects. Also, lipid peroxidation showed correlations of various degrees with atherogenic lipid parameters in both periods of the followed-up patients. In conclusion, patients with Behçet's disease in the active period may be much more susceptible to atherogenic events than those in the inactive period of the disease and control subjects.

Introduction

Behçet's disease is a chronic multisystemic disorder which is characterized by a relapsing systemic inflammatory process, particularly affecting the vascular bed. A number of published reports showed that various functions of polymorphonuclear (PMN) leukocytes in peripheral blood, such as chemotaxis, phagocytosis, and superoxide radical anion (O₂⁻) generation are increased in Behçet's disease 1, 2. PMN-mediated tissue injury has been thought to be a consequence of lysosomal degranulation 3, 4. However, neuthrophil-derived oxygen intermediates seem to contribute to tissue damage, especially in the endothelial tissue, more than lysosomal enzymes [5]. Neuthrophil-derived oxygen intermediates also affect lipid and lipoproteins and cause their oxidation. Therefore, oxidation products occur. Lipids and lipoprotein peroxidation are considered to be important in the pathogenesis of atherosclerosis 6, 7. Lipid and lipoprotein profiles and their relationship to atherogenesis in patients with Behçet's disease were described in previous studies 8, 9, 10. A way of estimating the free radical activity and lipid peroxidation is to determine the concentration of malondialdehyde (MDA) in plasma which is the most widely used test and is an easy initial screening test [11].

The aim was to reveal the relationships between MDA, lipid, lipoproteins and apoproteins in patients with Behçet's disease in the active and inactive periods.