title: Assessment of between-instrument variations in a HPLC method for serum lipoproteins and its traceability to reference methods for total cholesterol and HDL-cholesterol.
abstract: BACKGROUND
  The main purpose of this study was to evaluate the between-instrument variation of the HPLC method for the measurement of total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), VLDL-cholesterol (VLDL-C), chylomicron cholesterol (CM-C), LDL size, and HDL size. Furthermore, the accuracy of the HPLC was assessed for the determination of TC and HDL-C, compared with CDC reference methods.
  
  
  METHODS
  We used four HPLC instruments with different column-load numbers from 250 to 5000. For accuracy assessment of TC and HDL-C, we used the reference methods recommended by the CDC.
  
  
  RESULTS
  The values measured by the four instruments were highly correlated with each other (mean r = 0.965), and the absolute mean differences were 4-43 mg/L for TC, 4-30 mg/L for HDL-C, 0-48 mg/L for LDL-C, 7-66 mg/L for VLDL-C, 0-7 mg/L for CM-C, 0.1-0.3 nm for LDL size, and 0-0.1 nm for HDL size. For TC, the HPLC instruments showed high correlation and good agreement with the reference method: r = 0.997; total error <6.6%; absolute mean bias <1.2%. For HDL-C, the results from the HPLC method were significantly higher (10.8% absolute mean bias) than those of the CDC reference method, in spite of good correlation between the two methods (r = 0.998).
  
  
  CONCLUSIONS
  The between-instrument variation in serum lipoprotein analysis by HPLC was confirmed to be very small. This method met the US National Cholesterol Education Program's performance criteria for TC but not for HDL-C.
authors.affiliation: School of Allied Health Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Usui
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Jitsukata
authors.forename: M
authors.initials: M
authors.lastname: Nara
authors.forename: S
authors.initials: S
authors.lastname: Hosaki
authors.forename: M
authors.initials: M
authors.lastname: Okazaki
mesh_terms: D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000592:standards; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D012015:Reference Standards
chemical_list: D008076:Cholesterol, HDL; D008074:Lipoproteins; D002784:Cholesterol