Quantification of human serum lipoprotein Lp(a): zone immunoelectrophoresis assay, a new sensitive method as compared to electroimmuno assay.

This study aimed at improving the immunological procedures for the quantification of human serum lipoprotein Lp(a). Lipoprotein Lp(a) was estimated by two immunoelectrophoretic methods: electroimmunoassay and zone immunoelectrophoresis assay. Whereas the electroimmunoassay gave curvilinear calibration lines (in peak height versus concentration plots) the zone immunoelectrophoresis assay revealed linearity in the same concentration range. The results obtained are in good agreement with each other (r = 0.975). The inter-assay coefficient of variation for the zone immunoelectrophoresis assay was 12% as determined by the use of a lyophilised reference serum. Zone immunoelectrophoresis assay is recommended for the routine quantification of lipoprotein Lp(a). Although the levels for total cholesterol (p less than 0.0025), HDL-cholesterol (p less than 0.001) and triglycerides (p less than 0.025) differed significantly between male (n = 24) and female (n = 22) individuals, no difference could be detected comparing the frequency distributions of Lp(a)-levels found for the male and the female group.