Erythrocyte membrane, plasma and atherosclerotic plaque lipid pattern in coronary heart disease

The objective was to analyze the lipid composition of the atherosclerotic plaque (AP), plasma and erythrocyte membrane (EM) in patients with advanced coronary heart disease (CHD). AP were obtained through endarterectomy in 18 patients. Ten normolipemic healthy subjects were selected to obtain the normal lipid pattern profile. Total lipids of AP and EM were determined by HPTLC, and the fatty acid profile from AP, EM and plasma using TLC-FID. The relative amount of the lipid species analyzed in AP was in line with the data in the literature [phospholipids: 23.5 mol% +/- 3.5; total cholesterol 68.9 mol% +/- 7.9; triglyceride 7.6 mol% +/- 3.4]. Plasma and EM from CHD patients compared to controls, showed a decrease in polyunsaturated fatty acids and an increase in saturated fatty acids leading to a decrease in the unsaturation index (plasma: 1.67 +/- 0.06 vs. 1.28 +/- 0.03, P < 0.05; EM: 2.28 +/- 0.04 vs. 1.25 +/- 0.010, P < 0.05) and an enhancement in the saturated/unsaturated ratio (plasma: 0.35 +/- 0.02 vs. 0.52 +/- 0.02, P < 0.05; EM: 0.45 +/- 0.01 vs. 0.83 +/- 0.04, P < 0.05). These data are consistent with an essential fatty acid deficiency. Total cholesterol was increased in the CHD's EM (32.3 +/- 0.8 vs. 40.6 +/- 2.5, P < 0.05) with a decrease in phospholipid percentage (67.7 +/- 0.7 vs. 59.4 +/- 2.6, P < 0.05) indicating an alteration in membrane fluidity. These findings suggest changes in EM lipids in CHD patients in spite of different pathological conditions such as age, smoking status and diabetes. The analysis of the lipid composition of EM could provide a useful tool to monitor the evolution of the CHD.