Behcet'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 Behcet'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 (C-3, C-4) were evaluated in patients in active and inactive periods of Behcet'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 Behcet'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. (C) 1997 Elsevier Science Ireland Ltd.