Apolipoprotein B quantified by particle-concentration fluorescence immunoassay

Area of Science:

• Biochemistry
• Clinical Chemistry
• Immunology

Background:

• Apolipoprotein B (apo B) is a key lipoprotein associated with cardiovascular risk.
• Accurate measurement of apo B is crucial for assessing and managing cardiovascular disease (CVD).
• Existing assays may have limitations in speed, automation, or accuracy.

Purpose of the Study:

• To develop and validate a novel particle-concentration fluorescence immunoassay (PCFIA) for quantifying plasma apolipoprotein B (apo B).
• To compare the performance of PCFIA with established methods like enzyme-linked immunosorbent assay (ELISA).
• To evaluate the clinical utility of PCFIA in a pilot study involving patients with diabetes and coronary artery disease (CAD).

Main Methods:

• Developed a two-step antigen-detection PCFIA using polyclonal and monoclonal antibodies against apo B.
• Utilized narrow-cut low-density lipoproteins as the primary standard for calibration.
• Validated the assay against ELISA and assessed its performance with various lipoprotein fractions and plasma samples.
• Analyzed apo B concentrations in a pilot cohort of patients with diabetes, CAD, or both.

Main Results:

• The developed PCFIA method provides accurate estimation of plasma apo B concentrations.
• The PCFIA assay demonstrates comparable performance to ELISA.
• The assay is fully automatable and can be completed within 3 hours.
• Statistically significant differences in apo B levels were observed between patients with combined diabetes and CAD versus those with diabetes alone or controls (P < 0.01).

Conclusions:

• PCFIA is a reliable, efficient, and automatable method for measuring plasma apo B.
• The assay shows potential for clinical application in identifying individuals at higher cardiovascular risk.
• Findings highlight the elevated apo B levels in patients with comorbid diabetes and CAD, underscoring the need for targeted management.