Serum was obtained from patients with SLE after a 12-hour fast in the morning. Processed serum was stored at −80°C until retrieval for analyses. Analyses were performed for total cholesterol, triglycerides, HDL by automated clinical chemistry analyzer (AU5800, Beckman Coulter, Florida) in NUH, a College of American Pathologists accredited laboratory. LDL was calculated using the Friedewald formula. LDL and HDL subfractions were analysed using Lipoprint LDL System (which resolves up to 12 lipoprotein subfractions: very LDL (1), mid-band (3), LDL (7) and HDL (1); Lipoprint, Quantimetrix Corporation, California) and Lipoprint HDL System (which separates HDL into 10 subfractions; Lipoprint, Quantimetrix Corporation, California), respectively. Mid-bands comprise mainly of intermediate-density lipoproteins. HDL 1–3, 4–7 and 8–10 are classified as large, intermediate and small subfractions by the Lipoprint HDL System, respectively. The relative area (%) for each lipoprotein band is determined and multiplied by the total cholesterol concentration of the sample to yield the amount of cholesterol for each band (mg/dL).