Apolipoprotein B, Serum

Diagnostic Use

Apolipoprotein B (ApoB) is the principal protein component of low-density lipoprotein (LDL). Whilst the amount of cholesterol contained within LDL varies, each LDL particle contains exactly one ApoB protein. Co-measurement of ApoB with LDL enables deduction about LDL particle size and atherogenicity. It is usually only requested within the domain of the Lipid Clinic.

Department

Lipids/Trace Metals

Delphic Registration Code

APOB

Laboratory Handling

Separating

Separate serum within 4 hours of collection. Aliquot to Lipids / Trace Metals- Fridge

Laboratory

Gross haemolysis Reject, gross lipemia OK, gross icterus Reject

Test Adds

Stable ambient 24 hours, refrigerated for 8 days, frozen 60 days.

Synonyms

APO B
Lipoprotein B

Turnaround Time

5 days

Test Code

4163

Specimen Type

• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Preferred if West Coast

• SST II (Gold Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

3

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

1

Additional Specimen Information

Lithium heparin and EDTA plasma are NOT acceptable.

Aliquot Instructions

Sample Type

• Serum

Minimum Volume (ml)

0.3

Transport to Lab

Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

500 uL serum. Fridge 4°C. Minimum 300 uL serum

Interpretation

Co-measurement of ApoB with LDL enables deduction about LDL particle size and atherogenicity. For any given LDL concentration, a higher ApoB concentration implies a greater number of LDL particles, which are smaller and denser, also more atherogenic – sometimes termed ‘pattern B’. Conversely, a lower ApoB concentration implies LDL particles which are larger and less-dense, also less atherogenic.

Measurement may assist in assessing atherogenicity of a lipid profile and response to treatment, although it is rarely requested outside the Lipid Clinic.

ApoB is strongly associated with increased risk of developing cardiovascular disease (CVD) and often outperforms LDL-C at predicting CVD risk in some epidemiological and other studies.

A low apoB may help to corroborate disorders where LDL-cholesterol is very low, eg familial hypo-beta-lipoproteinaemia.

Reference Intervals

Male reference range 0.52 – 1.09 g/L

Female reference range 0.49 – 1.03 g/L

Test Method

Immunoturbidimetric

Non-Funded Test Cost

$18.13 (Exclusive of GST)

Billing Code

4163

Contact Information

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