Apolipoprotein B-48 (Apo B-48) ELISA Kits

Lipoproteins are complexes composed of lipids and proteins in a defined ratio and primarily function in lipid transport within the body. On the surface of lipoproteins, apolipoproteins play crucial roles in stabilizing the lipoprotein structure, activating enzymes involved in lipoprotein metabolism, and binding to lipoprotein receptors on the cell surface.

Apolipoprotein B-48 (Apo B-48) is a structural protein specific to chylomicrons (CM), which transport exogenous lipids, primarily derived from food, to the liver and peripheral tissues (Figure 1). It has a molecular weight of approximately 264,000 Da and shares 48% amino acid sequence homology with Apo B-100, the apolipoprotein present in lipoproteins responsible for endogenous lipid transport, including VLDL, LDL, and HDL.

Apo B-48 is regarded as an optimal marker for monitoring postprandial exogenous lipid transport. By measuring Apo B-48, HDL cholesterol, and LDL cholesterol in the same sample, changes in exogenous and endogenous cholesterol levels can be assessed¹⁾. Additionally, fasting Apo B-48 levels have been reported as a potential marker for postprandial hyperlipidemia²⁾. Apo B-48 is also considered valuable in assessing CM remnants, which are associated with conditions such as peripheral artery disease (PAD), cardiovascular diseases, endothelial dysfunction, and atherosclerosis affecting the cardiovascular system.

Figure 1. Lipoproteins and Apolipoproteins involved in lipid transport

The LBIS™ Human Apo B-48 ELISA Kit is a sandwich ELISA kit designed to quantify human Apo B-48. This kit contains antibodies specific to Apo B-48, with cross-reactivity to Apo B-100 below the detection limit.

Kit Performance

Calibration curve range	2.5-160 ng/mL
Assay target	Apo B-48
Analysis sample	Human serum/plasma (Citrate plasma cannot be used)
Sample volume	50 μL (100-fold dilution)
Measurement duration	Approx. 2 hours 50 minutes
Wavelength	Primary wavelength 450 nm Reference wavelength 620 nm

Example of Calibration Curve

Measurement Values for Human Samples (Fasting)

The above measurements are examples. Actual values may vary depending on blood collection methods and sample storage conditions.

Changes in Plasma Apolipoprotein Levels Following Fluvastatin and Omega-3 Fatty Acid Administration³⁾

Patients with type 2 diabetes and hyperlipidemia were administered either 80 mg of fluvastatin alone or 80 mg of fluvastatin combined with 4 g of omega-3 fatty acids. Blood samples were collected after a 12-hour fasting period, and Apo B-100 and Apo B-48 levels were measured in each sample.

[Result]
Apo B-48 levels significantly decreased following the administration of fluvastatin and omega-3 fatty acids.

Changes in Apo B-100 and Apo B-48 levels relative to baseline

Created from reference 3)

1. Otokozawa, S. et al.: Metabolism, 58(11), 1536(2009).
   Fasting and postprandial apolipoprotein B-48 levels in healthy, obese, and hyperlipidemic subjects
2. Reyes-Soffer, G. et al.: Diabetes Care, 36(2), 422(2013).
   Effect of combination therapy with fenofibrate and simvastatin on postprandial lipemia in the ACCORD lipid trial
3. Valdivielso, P. et al.: Cardiovasc. Diabetol., 8, 1(2009).
   Omega 3 fatty acids induce a marked reduction of apolipoprotein B48 when added to fluvastatin in patients with type 2 diabetes and mixed hyperlipidemia: a preliminary report