Comparison of the difference between serum lipoprotein(a) particle concentration and mass concentration in patients with chronic kidney disease / 中华检验医学杂志

ABSTRACT

Objective:To compare the difference between serum lipoprotein(a) [Lp(a)] particle concentration and mass concentration in chronic kidney disease (CKD) patients and healthy controls, and to analyze the concentration distribution of the deviations between the two measurement methods.Methods:Serum Lp(a) particle concentration and mass concentration were respectively detected in 196 patients with CKD and 97 healthy controls from Eastern Theater General Hospital during June 2018 to December 2019. The upper limit of reference value for Lp(a) particle concentration was set as 75 nmol/L and the upper limit of reference value for mass concentration was set as 300 mg/L, the difference on the positive rates of Lp(a) particle concentration and mass concentration in each group were compared. According to the quartile of Lp(a) concentration in patients with CKD, the patients were divided into 4 groups, and the results derived from the two methods were compared among groups.Results:Serum Lp(a) particle concentration (25.7 [10.5, 75.4] nmol/L vs 19.2[8.1-50.2] nmol/L, P=0.021) and mass concentration (157[64, 432] mg/L vs 127[50-274] mg/L, P=0.023) were significantly higher in patients with CKD than those in healthy controls. The positive rate of Lp(a) particle concentration was significantly lower than that of mass concentration (25.0%[48/196] vs 37.2%[73/196], P=0.009) in CKD patients. The positive rate of Lp(a) particle concentration and mass concentration was similar in healthy controls (18.6%[18/97] vs 22.7%[22/97], P=0.478). The overestimation rate of Lp(a) mass concentration in CKD patients was significantly higher than that in healthy controls (12.8%[25/196] vs 4.1%[4/97], P=0.020). Lp(a) mass concentration of group Ⅲ in CKD patients was between 157.00-432.25 mg/L, the positive rate of Lp(a) particle concentration was significantly lower than that of mass concentration (4.1%[2/49] vs 49%[24/49], P<0.001), and the overestimation rate (44.9%[22/49]) of Lp(a) mass concentration in this group was also the highest (all P<0.001). According to the conversion factor provided by the reagent manual of Lp(a) particle concentration, the test results were converted into mass concentration. The actual mass concentration of Lp(a) in CKD patients grouped by quartile was significantly higher than that after Lp(a) particle concentration conversion (all P<0.05). Conclusions:The positive rate of serum Lp(a) particle concentration is significantly lower than that of mass concentration in CKD patients and the obvious overestimation deviation of Lp(a) mass concentration is observed in this analysis.