Asparaginase

Diagnostic Use

A plasma trough level > 100 U/L is considered therapeutic and would be expected to achieve complete asparagine depletion.

A plasma trough level between 50-100 U/L is considered sub therapeutic and may require dosing adjustment.

A plasma trough level < 50 U/L may indicate the presence of inactivating antibodies (with or without manifestations of clinical hypersensitivity). An alternative form of Asparaginase should be considered.

Department

Specialist Biochemistry

Delphic Registration Code

SENB

Laboratory Handling

Separating

Aliquot to Specialist Biochemistry - Freezer

Laboratory

Freeze plasma on arrival in laboratory

Turnaround Time

4 weeks

Specimen Type

• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Acceptable

• Lithium Heparin - Gel (Green Cap)

Preferred Sample Volume (ml)

4.5

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Acceptable

• Lithium Heparin - Gel (Green Cap)

Preferred Sample Volume (ml)

4.5

Additional Specimen Information

Pre-Testing Requirements - Request form must give the following information:
Asparaginase type : PEG or Erwinia
Dose amount ( U/m2 ), date of dose
Evidence of allergic reaction; confirmed / suspected / no evidence
weight (Kg) & height ( cm)

Specimen Collection Protocols:
For patients on PEG asparaginase collect samples at 7 & 14 days post dose, or at time of reaction.
For patients on Erwinia asparaginase collect samples at 48 & 72 hours post dose, or at the time of reaction.

Aliquot Instructions

Sample Type

• Plasma

Minimum Volume (ml)

1.0

Transport to Lab

Frozen
If overnight - Frozen

Additional Referral/Aliquot Information

Aliquot plasma into 2 separate aliquots and send frozen to CHL ( prefer 0.5 mL in each aliquot)

Interpretation

The therapeutic goal is to achieve asparaginase activity > 100 U/L for the dosing interval ( 14 days after PEG and 72 hours after Erwinia)

Reference Intervals

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

Asparaginase is stable in plasma at -4 oC for up to 3 years, It is stable at room temperature and at 4oC once separated for up to one week.

Contact Information

Enquiry Form