|
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
METHOTREXATE LEVEL
Test CodeLAB481
CPT Codes
80299
Preferred Specimen
One 6 mL RED top tube. Protect from light.
Pediatric: One red top microtainer
Pediatric: One red top microtainer
Other Acceptable Specimens
Dark green top tube
Instructions
Specify dosage history. Time drawn must be written on label.
Sample must be centrifuged within 2 hours of collection. Serum/plasma (red or dark green top tube) must be removed from the red cells and put into amber aliquot tubes following centrifugation.
Sample must be centrifuged within 2 hours of collection. Serum/plasma (red or dark green top tube) must be removed from the red cells and put into amber aliquot tubes following centrifugation.
Transport Temperature
Refrigerated
Specimen Stability
Unstable, centrifuge within two hours of collection and protect from light.
Ambient: 4 hours
Refrigerated: 2 weeks
Frozen: not specified
Ambient: 4 hours
Refrigerated: 2 weeks
Frozen: not specified
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Samples drawn in tubes containing a separator gel may cause falsely lower results.
Methodology
Enzyme Immunoassay
Setup Schedule
Sunday-Saturday
Reference Range
Critical Value: ≥10.00 umol/L
Reference Interval: Therapeutic intervals may vary depending on treatment regimen.
Following a 2-4 hour IV infusion of 500 mg/m2 – 12000 mg/m2:
24 Hour Sample: < 10 µmol/L
48 Hour Sample: < 1.0 µmol/L
72 Hour Sample: < 0.2 µmol/L
Following a 24 hour HDMTX (5000 mg/ m2) infusion for pediatric ALL:
24 Hour Sample: < 120 µmol/L
36 Hour Sample: < 3.0 µmol/L
42 Hour Sample: < 1.0 µmol/L
48 Hour Sample: < 0.4 µmol/L
Glucarpidase rescue therapy interferes with measurement; mass spectrometry testing is suggested in such cases where glucarpidase is administered prior to sampling.
Reference Interval: Therapeutic intervals may vary depending on treatment regimen.
Following a 2-4 hour IV infusion of 500 mg/m2 – 12000 mg/m2:
24 Hour Sample: < 10 µmol/L
48 Hour Sample: < 1.0 µmol/L
72 Hour Sample: < 0.2 µmol/L
Following a 24 hour HDMTX (5000 mg/ m2) infusion for pediatric ALL:
24 Hour Sample: < 120 µmol/L
36 Hour Sample: < 3.0 µmol/L
42 Hour Sample: < 1.0 µmol/L
48 Hour Sample: < 0.4 µmol/L
Glucarpidase rescue therapy interferes with measurement; mass spectrometry testing is suggested in such cases where glucarpidase is administered prior to sampling.
Performing Laboratory
West Virginia University Hospital, Inc.
