Test Entry - Detail

Plasma Uracil

General

Clinical Use:

Plasma uracil can be measured in patients prior to fluoropyrimidine (FP) chemotherapy (5-Fluorouracil, capecitabine).
The risk of acute toxicity with FP therapy increases with increasing uracil concentrations, associated with increasing risk of dihydropyrimidine dehydrogenase (DPD) deficiency.
Patients with DPD deficiency have impaired ability to metabolise FP medications, and are at increased risk of early, severe, treatment related toxicity.
Test is NOT CPOE orderable.
Requesting is restricted to Medical Oncology clinicians and a specific template request form must be completed.
Currently only available for collection at PathWest SCGH, FSH and Rockingham Monday to Friday before 3pm.
Patients attending other collection centres or outside these times should be directed to return for collection at PathWest SCGH, FSH and Rockingham Monday to Friday before 3pm.
Samples collected at private pathology provider collection centres will NOT be accepted due to the stringent pre-analytical handling requirements of these samples.

Availability:

Samples are batched and tested twice a week.

Aliases/Synonyms:

Plasma Uracil and Dihydrouracil, Uracil,

Code:

UDPD

Handling Instructions (to laboratory):

Deliver sample on ice to laboratory immediately following collection.

Hyperlink:

Reference Interval:

<16ug/L       NORMAL, lowest risk of acute toxicity with fluoropyrimidine (FP) therapy (5-Fluorouracil (5-FU), capecitabine)
16-<150ug/L   The risk of acute toxicity with FP therapy increases with increasing uracil concentration in this range, associated with increasing risk of DPD deficiency
>=150ug/L     Greatly increased risk of acute, severe toxicity with FP therapy, associated with complete DPD deficiency

Collection Requirements

Container:

Lithium Heparin, No Gel (DKGNLITH),

Sample Type:

See container

Minimum Collection Volume:

2mL

Collection Instructions:

Call CSRA supervisor at time of collection (site specific contact number will appear as a pop-up at time of registration).
Collect sample on ice and hand deliver to laboratory immediately.
Give sample directly to CSRA supervisor.

Processing Requirements

Alternate Containers:

Processing Instructions:

Sample must be processed immediately upon arrival in laboratory.
Centrifuge, separate all plasma into 2 aliquots and freeze at -20C within 1 hour of collection.
CSRA staff to complete time of receipt, separation and freezing on request form.
DO NOT CANCEL TEST UNDER ANY CIRCUMSTANCES. PROCESS ALL SAMPLES - IF SPECIMEN FAILS TO MEET COLLECTION CRITERIA CONTACT QEII SPECIAL CHEMISTRY STAFF.

Minimum Assay Volume:

500uL

Stability:

1 hour ambient

Transport Instructions (to testing laboratory):

Send separated sample frozen on dry ice.
Samples being transported from FSH to QEII:
Ensure esky is labelled with "Urgent Uracil" label and contact QEII supervisor (63834064) to notify them of dispatch.

Testing Locations

Performed at:

Section	Department	Site	Contact Phone
Special Chemistry	Biochemistry	QEII Medical Centre	6383 4114

Last Updated : 27-10-2025 11:49