| Objective To compare the serum lipoprotein(a)[Lp(a)] particle concentration and mass concentration method and evaluate its clinical application.Methods The serum Lp(a)levels of 719 samples were determined by two particle concentration methods(nmol/L)and two mass concentration methods(mg/L),and the correlation and consistency of results were compared.According to the particle concentration results,all samples were divided to group I(Lp(a)<75noml/L)and group II(Lp(a)>75noml/L).The two particle concentrations were converted into mass concentration results by the conversion factor provided by the different manufacturers,respectively.The results of the two mass concentration methods and the converted mass concentration results were compared respectively.Results The correlation between the two particle concentration detection methods is good.Compared to two particle concentration methods,two mass concentration methods both showed good correlations.However,when serum Lp(a)<75nmol/L,the results of two mass concentration methods and particle concentration method were inconsistent in 6.7%,8.5% and 9.1% samples,respectively.In group I and group II,the difference between two mass concentration results was statistically significant(p<0.05),but the mean deviation(16.89%)was within the clinical allowable total error(30%).The bias was significantly reduced when Lp(a)>75nmol/L in group II,the mean deviation was 4.64%(<1/3 clinical allowable total error).The same results also exist between Diasys mass concentration and the Diasys converted mass concentration,and between Kehua mass concentration and the Roche converted mass concentration.Conclusions Two methods for serum Lp(a)mass concentration both overestimate the Lp(a)levels compared with particle concentration.Moreover,when the Lp(a)levels of the samples were low(Lp(a)<75nmol/L),the overestimation was particularly obvious.There are also differences between different mass concentration methods,but the deviation is within the clinical allowable total error range.In addition,due to the size heterogeneity of Lp(a)molecules in different individuals and the variability of their components,it is not recommended to use conversion factors to convert the detected results between particle concentration method and mass concentration method.The particle concentration detection method can better reflect the true level of individual Lp(a),so it can better play the clinical application value of Lp(a).Objective To establish and validate the reference interval of particle concentration and mass concentration methods for detecting serum lipoprotein(a)[LP(a)],and to provide a basis for screening healthy population and risk assessment of cardiovascular diseases.Methods A total of 290 healthy subjects with normal biochemical indexes were randomly selected from the Physical Examination Center of the First Affiliated Hospital of Anhui Medical University from June to September 2020,excluding heart and lung insufficiency or other diseases affecting lipid metabolism,such as liver disease,kidney disease,thyroid disease,etc.Serum Lp(a)levels were detected by the method of Lp(a)particle concentration(nmol/L)and the method of Lp(a)mass concentration(mg/L),respectively,and statistical analysis was performed.Results The reference intervals(95th percentile)of particle concentration and mass concentration methods for Lp(a)detection were 118.3 nmol/L and 547 mg/L,respectively,which were higher than the reference ranges provided by manufacturers,and there was no significant difference between men and women.The reference intervals determined by the 75 th percentile was 56.3nmol/L and 295mg/L,both within the range provided by the manufacturer.Conclusions Due to differences in serum Lp(a)test results between different races and different methods,the laboratory should establish the corresponding reference interval according to the specific situation and adopt appropriate statistical methods to meet the clinical needs. |
PDF Full Text Request