An enzyme-linked immunosorbent assay for measuring GPIHBP1 levels in human plasma or serum

• Published in: Journal of clinical lipidology Vol. 12; no. 1; pp. 203 - 210.e1
• Main Authors: Miyashita, Kazuya, Fukamachi, Isamu, Nagao, Manabu, Ishida, Tatsuro, Kobayashi, Junji, Machida, Tetsuo, Nakajima, Kiyomi, Murakami, Masami, Ploug, Michael, Beigneux, Anne P., Young, Stephen G., Nakajima, Katsuyuki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2018
• Subjects: Aged; Antibodies, Monoclonal - immunology; Cardiovascular Diseases - pathology; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein-1; Humans; Lipoprotein lipase; Lymphocyte antigen 6; Male; Metabolic Diseases - pathology; Middle Aged; Monoclonal antibody; Receptors, Lipoprotein - blood; Receptors, Lipoprotein - immunology; Triglyceride-rich lipoproteins; Triglycerides - blood; Urokinase-type plasminogen activator receptor; Urokinase-type plasminogen activator receptor; Glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein-1; Triglyceride-rich lipoproteins; Lipoprotein lipase; Monoclonal antibody; Lymphocyte antigen 6
• ISSN: 1933-2874; 1876-4789
• DOI: 10.1016/j.jacl.2017.10.022

Glycosylphosphatidylinositol-anchored high-density lipoprotein–binding protein 1 (GPIHBP1), a glycosylphosphatidylinositol (GPI)-anchored protein of capillary endothelial cells, transports lipoprotein lipase to the capillary lumen and is essential for the lipolytic processing of triglyceride-rich lipoproteins. Because some GPI-anchored proteins have been detected in plasma, we tested whether GPIHBP1 is present in human blood and whether GPIHBP1 deficiency or a history of cardiovascular disease affected GPIHBP1 circulating levels. We developed 2 monoclonal antibodies against GPIHBP1 and used the antibodies to establish a sandwich enzyme-linked immunosorbent assay (ELISA) to measure GPIHBP1 levels in human blood. The GPIHBP1 ELISA was linear in the 8 to 500 pg/mL range and allowed the quantification of GPIHBP1 in serum and in pre- and post-heparin plasma (including lipemic samples). GPIHBP1 was undetectable in the plasma of subjects with null mutations in GPIHBP1. Serum GPIHBP1 median levels were 849 pg/mL (range: 740–1014) in healthy volunteers (n = 28) and 1087 pg/mL (range: 877–1371) in patients with a history of cardiovascular or metabolic disease (n = 415). There was an extremely small inverse correlation between GPIHBP1 and triglyceride levels (r = 0.109; P < .0275). GPIHBP1 levels tended to be slightly higher in patients who had a major cardiovascular event after revascularization. We developed an ELISA for quantifying GPIHBP1 in human blood. This assay will be useful to identify patients with GPIHBP1 deficiency and patients with GPIHBP1 autoantibodies. The potential of plasma GPIHBP1 as a biomarker for metabolic or cardiovascular disease is yet questionable but needs additional testing. •We developed a sensitive sandwich enzyme-linked immunosorbent assay to measure GPIHBP1 in human plasma or serum.•The plasma GPIHBP1 levels were very low in patients harboring loss-of-function mutations in GPIHBP1.•A slight trend toward higher serum GPIHBP1 levels was observed in a cohort of patients with coronary heart disease, but this finding needs to be tested in larger patient cohorts.