Apolipoprotein A-I and B

Immunology

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Description

Apolipoprotein A-I is the main protein component of high density lipoprotein (HDL). It is involved in activating the pathway which leads to esterification of cholesterol, after which it can then be transported to the liver for metabolism and excretion [1]. Some patients that show atherosclerotic vascular changes have been shown to have low levels of apolipoprotein A-I [3]. Decreased levels may also be seen in dyslipoprotienaemias, acute hepatitis, cirrhosis and insulin-treated diabetics. Apolioprotein B is the main component of low density lipoprotein (LDL). It is needed for the reaction of LDL receptors in the liver and on cell walls in order to transport cholesterol from the liver. Elevated apolipoprotein B levels have been observed in patients with atherosclerotic vascular changes [3]. It is thought that the ratio of apolipoprotein B/A-I is a powerful tool in estimating the risk of developing atherosclerosis, with a higher ratio being indicative of a greater risk of disease development [2].

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Indications

Atherosclerosis.

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Sample Type

2mL Serum (Gel 5mL Yellow tube) or 2mL heparinised plasma.
Requests from outside Sheffield: transport at ambient temperature via Royal Mail or Courier.

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Reference Range

Apolipoprotein A-I
Male 1.10 - 2.05 g/L
Female 1.25 - 2.15 g/L

Apolipoprotein B
Male 0.55 - 1.40 g/L
Female 0.55 - 1.25 g/L

Apo B/Apo A-I ratio
Male 0.35 - 1.00
Female 0.30 - 0.90

Reference ranges established by manufacturer and verified in-house.

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Turnaround Time

Within 10 days

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Testing Frequency

As required

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References

Tsompanidi EM, et al. HDL biogenesis and functions: Role of HDL quality and quantity in atherosclerosis. Atherosclerosis. 2010. 208:3-9. [Ref 1]
Lind L. Apolipoprotein B/A-1 and risk of cardiovascular disease. The Lancet. 2008. 372:185-186. [Ref 2]
Sacks FM. The apolipoprotein story. Atherosclerosis Sup. 2006. 7:23-27. [Ref 3]

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.