Apolipoprotein B
Norm
Women 0.60–1.17g/l
Men 0.66–1.33g/l
Normal ratio of Apo A1/Apo B
More than 1.2
Synonyms: Apo B, apolipoprotein B.
Serum, plasma EDTA, heparin (do not freeze!)
Cap color: red, green, or violet
The test is performed only when determining apolipoprotein A1. The concentration of Apolipoprotein B in the blood is determined in order to calculate the Apo A1/Apo B ratio. The higher this ratio, the lower the risk of atherosclerosis. Apolipoprotein B is associated with LDL cholesterol (“bad” cholesterol), so lower values are a favorable prognostic factor for atherosclerosis, coronary heart disease.
Determination of apolipoproteins is important when: 1) the patient has elevated or moderately elevated lipid levels (when testing for cholesterol, LDL cholesterol, triglycerides); 2) individuals suspected of lipid metabolism disorders (e.g., 10% of all myocardial infarction patients are diagnosed with familial combined hyperlipidemia).
Lipid levels when Apo should be tested:
Cholesterol – 5.2–7.8mmol/l;
Triglycerides – 2.3–4.6mmol/l;
LDL cholesterol – 3.5–4.5mmol/l.
Other apolipoproteins used in scientific studies of atherosclerosis currently do not have broader clinical application. Their norms are presented in the table.
Apolipoproteins play a certain pathophysiological role in the body: a) transport of water-insoluble lipids in the blood; b) transport of lipid components from one cell to another; c) degradation of blood lipid components; d) enzyme cofactors. Apolipoproteins B interact with cell receptors and can lead to unwanted deposition of LDL cholesterol in blood vessels. There are two forms of apolipoprotein B prevalent in the body: a) Apo B–48 and Apo B–100. Apo B–48 is synthesized in the intestine, while Apo B–100 is synthesized in the liver.
Serum frozen on ice is not suitable for testing.
Source | Handbook of Basic Laboratory Tests | Doctor of Medical Sciences Gintaras Zaleskis