Quantitative molar concentration detection of specific apolipoprotein-containing particles present in bodily fluids by using capillary electrophoresis

A method of assessing cardiovascular risk in a subject, comprising:

• (i) determining the particle number and/or molar concentration of a lipoprotein in a biological sample from the subject;
• and
• (ii) assessing the cardiovascular risk of the subject based on the particle number and/or molar concentration of the lipoprotein;
• wherein the particle number and/or molar concentration of the lipoprotein is determined by:
• (a) contacting the biological sample with a fluorophore-labeled antibody under conditions suitable for the fluorophore-labeled antibody to bind to the lipoprotein or an immunologically active component thereof, to form a fluorophore-labeled lipoprotein;
• (b) subjecting the fluorophore-labeled lipoprotein to a capillary isotachophoresis laser-induced fluorescence (CE-ITP-LIF) system;
• (c) detecting signals produced by the fluorophore-labeled lipoprotein;
• and
• (d) quantifying, based on said detecting, the particle number and/or molar concentration of the of the lipoprotein in the sample, wherein the detected signals are proportional to the particle number and/or molar concentration of the lipoprotein.

The method according to any of the preceding claims, wherein the signal produced by the fluorophore-labeled antibody is measured and the molar concentration and/or particle number of the lipoprotein is determined based on the following formula:

• PN=(relative AUC value)×(total apolipoprotein concentration)
• wherein:
• PN is equal to particle number in
• (
• nmol
• L
• )
• ;
• (relative AUC value) is determined by calculating the relative optical density of a specific peak as a portion of the optical density of all peaks;
• and (total apolipoprotein concentration) is given in
• (
• nmol
• L
• )
• and is determined by measuring the specific total apolipoprotein concentration.

A system for determining the molar concentration and/or particle number of a lipoprotein in a biological sample, comprising:

• a capillary electrophoresis apparatus for separating components of a moiety-bound sample, wherein the moiety-bound sample is prepared by contacting the biological sample with a fluorophore-labeled antibody under conditions suitable for the fluorophore-labeled antibody to bind to the lipoprotein or an immunologically active component thereof, to form a fluorophore-labeled lipoprotein;
• a detector for detecting signals produced by the fluorophore-labeled lipoprotein;
• and
• a processor for quantifying, based on said detecting, the concentration and/or particle number of the lipoprotein in the sample, wherein the detected signals are proportional to the molar concentration and/or particle number of the lipoprotein in the sample.