Apolipoprotein CIII Mass Spectrometry for Congenital Disorders of Glycosylation (Research Only), Plasma

Diagnostic Use

Apolipoprotein CIII isoforms are used in the screening of congenital disorders of glycosylation (CDG). Apolipoprotein CIII isoform analysis is a complimentary evaluation to transferrin isoform analysis for CDG mixed and type II profiles. Abnormal Apolipoprotein CIII isoforms are a marker for O-linked CDG. Apolipoprotein CIII has mucin type O-glycosylation and can therefore be used to screen for O-linked CDGs, with defects involving the Golgi apparatus.

This method does not detect all CDGs, or CDGs in infants < 3 months of age. Some CDGs are not associated with abnormalities of Apolipoprotein CIII isoforms. Recent transfusions invalidate results.

This is a research assay and not covered by the laboratories IANZ accreditation, results should be interpreted accordingly.

Delphic Registration Code

MOLP

Laboratory Handling

Test Adds

Chilled (2 - 8 degrees Celsius)

Constituent Tests

• Transferrin Isoforms Mass Spectrometry for Congenital Disorders of Glycosylation, Serum

Synonyms

Apolipoprotein CIII isoforms
Apo CIII
Congenital disorder glycosylation
CDG

Turnaround Time

2 weeks

Test Code

MPST

Specimen Type

• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• Sodium Citrate (Light Blue Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

2

Minimum Sample Volume (ml)

1

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• Sodium Citrate (Light Blue Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

Ultracentrifugation is performed to separate the VLDL fraction from plasma, which is collected for analysis of Apolipoprotein CIII isoforms. To collect sufficient VLDL, approximately 1-2 mL of plasma is required.

If transporting plasma from overseas, please organise dry ice shipment.

Aliquot Instructions

Sample Type

• Plasma

Minimum Volume (ml)

1

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Frozen

Additional Referral/Aliquot Information

Ultracentrifugation is performed to separate the VLDL fraction from plasma, which is collected for analysis of Apolipoprotein CIII isoforms. To collect sufficient VLDL, approximately 1-2 mL of plasma is required.

If transporting plasma from overseas, please organise dry ice shipment.

Interpretation

Apolipoprotein CIII isoform analysis is indicated in the diagnostic work-up of CDG when an abnormal transferrin isoform pattern (mixed or type II) is detected, or when there is evidence of an O-linked CDG.

Reference Intervals

Apo CIII 0 / Apo CIII 2 < 0.48

Apo CIII 1 / Apo CIII 2 < 2.91

Test Method

Time of Flight Mass Spectrometry of Apolipoprotein CIII isoforms

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Contact Information

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