Rapid and specific detection of oxidized LDL/β2GPI complexes via facile lateral flow immunoassay

Xian Wen Tan; Fumiaki Takenaka; Hironori Takekawa; Eiji Mastuura

doi:10.1016/j.heliyon.2020.e04114

Rapid and specific detection of oxidized LDL/β2GPI complexes via facile lateral flow immunoassay

Heliyon. 2020 Jun 8;6(6):e04114. doi: 10.1016/j.heliyon.2020.e04114. eCollection 2020 Jun.

Authors

Xian Wen Tan¹, Fumiaki Takenaka², Hironori Takekawa³, Eiji Mastuura^{1

2

3

4}

Affiliations

¹ Department of Cell Chemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
² Collaborative Research Center (OMIC), Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
³ Faculty of Medicine, Okayama University, Okayama, Japan.
⁴ Neutron Therapy Research Center, Okayama University, Okayama, Japan.

Abstract

β2-Glycoprotein I (β2GPI) forms indissociable complex with oxidized LDL (oxLDL) into proatherogenic oxLDL/β2GPI complex through a specific ligand known as 7-ketocholesteryl-9-carboxynonanoate (oxLig-1). Recent discoveries have demonstrated the atherogenicity of these complexes in patients of both systemic and non-systemic autoimmune diseases. Hence, serological level of oxLDL/β2GPI complexes may represent one crucial clinical parameter for disease prognosis of atherosclerosis-related diseases. Herein, we established a simple, specific and rapid gold nanoparticle (GNP) based lateral flow immunoassay (LFIA) to quantify oxLDL/β2GPI complexes from test samples. Specificities of hybridoma cell-derived monoclonal antibodies against antigen, optimal conditions for conjugation of antibody with GNP, and sensitivity of oxLDL/β2GPI LFIA in comparison to an ELISA-based detection method were assessed accordingly. The established oxLDL/β2GPI LFIA was capable of detecting oxLDL/β2GPI specifically without interference from autoantibodies and solitary components of oxLDL/β2GPI present in test samples. A significant correlation (R² > 0.8) was also obtained with the oxLDL/β2GPI LFIA when compared to the ELISA-based detection. On the whole, the oxLDL/β2GPI LFIA remains advantageous over the oxLDL/β2GPI ELISA. The unnecessary washing step, short developmental and analytical time support facile and rapid detection of oxLDL/β2GPI as opposed to the laborious ELISA system.

Keywords: Antibody; Biochemistry; Biological sciences; Enzyme-linked immunosorbent assay (ELISA); Health sciences; Lateral flow immunoassay (LFIA); Lipid peroxidation; OxLDL-β2GPI; Oxidized LDL (oxLDL); Point-of-care; β2-glycoprotein I (β2GPI).