血脂分析測(cè)試的國(guó)家指南課件

1、National Guidelines on Lipid Profile Testing E-mail:yanshengkaiDr. Sheng-kai Yan , PhDDepartment of Laboratory Medicine, Peking Union Medical College HospitalProfessor zhou xin Department of Laboratory Medicine,Zhongnan hospital of wuhan university.Preface Blood lipid analysis has a substantial impo

2、rtance towards the prevention and management of atherosclerosis and coronary heart disease (CHD).It is also being widely applied to the studies of many other related clinical conditions, such as diabetes mellitus, kidney diseases, and metabolic disorders in postmenopausal women. Recently, the Lipid

3、Expert Panel of the Chinese Society of Laboratory Medicine (CSLM) of the Chinese Medical Association (CMA) has come up with the practical guidelines and recommendations on lipid profile testing.lipid profile testing: total cholesterol (TC) triglycerides (TG)high density lipoproteincholesterol (HDL-C

4、)low density lipoprotein-cholesterol (LDL-C)apolipoprotein A1 (ApoA1) apolipoprotein B (ApoB) lipoprotein(a) Lp(a)The Guidelines include the content as follows,PrefacePreanalytical factors affecting lipid test resultsMethods of lipid analysisReagent selection criteria and practical guidelinesClinica

5、l significance of cutoff values in the interpretation of lipid profile resultsSee: Chin J Lab Med, 2003, 26(3): 182184中華檢驗(yàn)醫(yī)學(xué)雜志,2003,26(3):182-184Preanalytical Factors Affecting Lipid Test ResultsA subjects lipid profile should be measured when the individual is in a steady metabolic state.Subjects s

6、hould maintain their usual diet and weight for at least 2 weeks prior to the measurement of their lipids or lipoproteins.Subjects should not perform vigorous physical activity during the 24 hours prior to testing. Recommendations for minimizing preanalytical variationMultiple measurements should be

7、performed whthin 2 months, at least one week apart, before making a medical decision about further action. Fasting or non-fasting specimens can be used for TC testing. However, a 12-h fasting specimen is required for TG and recommended for lipoproteins.The subject should be seated for at least 5 min

8、utes before specimen collection.The tourniquet should not be kept on more than one minute during venipuncture. Suggestions to reduce the preanalytical variations on blood lipid profile testingAnalytical Methods For routine lipid analysisSerum TC: Enzymatic method(CHOD-PAP method)Serum TG: Enzymatic

9、method( GPO-PAP method) Serum HDL-C: Homogeneous methods Serum LDL-C: Homogeneous methods Serum ApoA1/ApoB and Lp(a): Immunoturbidimetry(ITA) method Immunonephelometry(INA) method (The first choice would be ITA, followed by INA)Serum HDL-C Homogeneous methods Clearance method Synthetic polymer/ dete

10、rgent HDL-C assay, SPD Daiichi Pure Chemicals Co. Catalase HDL-C assay, CAT Denka Seiken Randox Co. Reference Diagnostics Polymedco Serum HDL-C Homogeneous methods PEG-modified enzyme HDL-C assay，PEGME Kyowa Medex Co. Roche Diagnostics Centronic GmbHProtecting reagent LDL-C assay，PRO Wako Chemicals

11、Sigma DiagnosticsCalixarene LDL-C assay，CAL International Reagents Co./Sysmex Solubilization LDL-C assay，SOLSerum LDL-C Homogeneous method Serum Lp(a)Immunoturbidimetry/immunonephelometry The reagent should preferably be polyclonal or mixed monoclonal antibodies, that could recognize different epito

12、pes of the Apo(a) molecule.ITA is more preferable than INA.Spectrophotometers and semi-/automatic biochemical analyzers would be suitable for analysis once verified for proper functioning. All samplers, dilutors, pipettes and micropipettes must be calibrated.Automatic biochemical analyzers (fully or

13、 semi-automatic) are recommended for use in blood lipid testing.Requirements on Analytical Instruments Parameters should be set according to the manufacturers instructions and assigned calibrator values on the package insert. The parameters should not be liberally changed.Setting the ParametersWhile

14、 choosing individual QC materials, one should consider carefully the dynamic range and the target values for the corresponding analytical methods. A parallel run should be performed for an overlapping period with both the current and new lot control materials. Enrolment to external quality assessmen

15、t programs is a MUST.Quality ControlReagent Selection Criteria and Practical Guidelines Inaccuracy and Imprecision Inaccuracy(Bias) Imprecision(CV) Total errors * TC 3% 3% 8.9% TG 5% 5% 15% HDL-C 5% 4% 13% LDL-C 4% 4% 12% ApoAI 3% 5% ApoB 3% 5% Lp(a) 4% 10% *Total errors=Bias%+1.96CVAnalytical Sensi

16、tivityWhen phenol is employed in enzymatic analysis of serum TC, the absorbance of TC = 5.2 mmol/L at 500nm (A500nm) is about 0.30-0.35. Therefore, A500nm of 0.005 should give 0.08 mmol/L TC.The sensitivity of TG enzymatic analysis should be A500nm 0.2 at TG 2 mmol/L.Analytical SensitivityIn using h

17、omogeneous assays for HDL-C and LDL-C, the minimal measurable level should be 0.01 mmol/L.The lowest detection limits for serum ApoA1 and ApoB by immunoturbidimetry or immunonephelometry should be 0.5 g/L, and that for Lp(a) should be 5 mg/L.LinearityThe upper limit of linearity is 13 mmol/L when us

18、ing the dilution ratio of 1:100 in enzymatic analysis of TC. It will lower the upper limit if smaller dilution ratios are used.The linearity of the enzymatic TG assay should at least be 11.3 mmol/L (1000 mg/dL). The linearity of homogeneous assays for HDL-C and LDL-C should at least be 2.59 mmol/L a

19、nd 7.77 mmol/L respectively.LinearityThe linearity of serum ApoA1 and ApoB by ITA or INA should not be less than 2.0 g/L and that of Lp(a) not less than 800 mg/L, respectively. SpecificityIn enzymatic analysis of serum TC, the color reaction is subject to certain degree of spectral interferences fro

20、m various non-cholesterol sterols. Normally, there is only negligible amount (about 1%) of these non-cholesterol sterols in the blood. In enzymatic analysis of TG, the lipoprotein lipase (LPL) can hydrolyze TG and also mono-glycerides and di-glycerides. The latter two constitute about 3% of total TG

21、 measured.SpecificityThe recoveries in homogeneous assays of HDL-C and LDL-C, immunoturbidimetry of serum ApoAI, Apo B and Lp(a) should preferable be in the range of 90%-110%. In general, the measurements should not be affected by other lipoproteins.There is no significant interference up to hemoglo

22、bin concentration of 2g/L, bilirubin concentration of 0.1g/L in enzymatic analysis of serum TC.Interference in enzymatic analysis of TG is similar to that of the TC assay. There will be negative interference when bilirubin 100mol/L or ascorbic acid170mol/L. Hemoglobin will cause spectral interferenc

23、es. Grossly hemolysed samples are not suitable for analysis. InterferencesThere is no significant interference of TG 5.65 mmol/L (500 mg/dl), bilirubin 513 mol/L (30 mg/dl), and Hb 5 g/L in most homogeneous assays for HDL-C and LDL-C, as well as the immunoturbidimetric or immunonephelomentric assays

24、 for serum ApoA1, ApoB and Lp(a). InterferencesReagent StabilityLyophilized reagents can usually be stored at least for 1 year if kept unopened at 28. Reconstituted cholesterol and TG enzymatic reagents should be stored at 28for 2 days. Reagents should be discarded if pink color is seen. The absorba

25、nce at 500nm of the reagent blank should be 0.05. Unopened reagent solutions should be stable for at least 6 months at 28 and for 1 month after being opened.Reaction Rates The reaction should not be longer than 5 min and 8 min at 37 for enzymatic analysis of serum cholesterol and TG respectively. Th

26、e endpoint of immunoturbidimetric assays for serum ApoA1, ApoB and Lp(a) could be determined according to their reaction curves shown in the automatic analyzer. Generally, reaction time of 8 10 minutes is acceptable. CalibrationThe user should use the calibration materials provided by the manufactur

27、er. The calibration materials should be traceable to the reference methods. One should avoid using different brands of calibration materials as to ensure consistence of the performance. CalibrationThe international standard serum preparations of WHO-IFCC should be used in the ITA or INA assays for ApoA1, ApoB and Lp(a). At least five different concentrations should be used to cover