| 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 : 648
Test CodeMTXAU or 648
CPT Codes
80204
Instructions
Collect 24, 48, or 72 hours after dose
Transport Container
Protect from light. Record hours from last dose on specimen container and on the test requisition.
Preferred Specimen
1 mL frozen serum collected in a red-top tube (no gel)
Alternative Specimens
Plasma collected in: EDTA (lavender-top) tube, fluoride oxalate (gray-top) tube, sodium or lithium heparin (green-top) tube
Minimum Volume
0.2 mL
Preferred Specimen
1 mL frozen serum collected in a red-top tube (no gel)
Alternative Specimens
Plasma collected in: EDTA (lavender-top) tube, fluoride oxalate (gray-top) tube, sodium or lithium heparin (green-top) tube
Minimum Volume
0.2 mL
Transport Temperature
Frozen.
Specimen Stability
Room temperature: 24 hours; Refrigerated: Unacceptable; Frozen: 5 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Serum separator tube (SST) or Received thawed
Methodology
Immunoassay
Setup Schedule
Sunday - Saturday
Report Available
1 day
Reference Range
<5.00 umol/L at 24 hours
<0.50 umol/L at 48 hours
<0.20 umol/L at 72 hours
For conventional low dose leucovorin rescue.
<0.50 umol/L at 48 hours
<0.20 umol/L at 72 hours
For conventional low dose leucovorin rescue.
Clinical Significance
Methotrexate is an antimetabolite used in the treatment of certain neoplastic diseases, psoriasis and rheumatoid arthritis. In combination with other chemotherapeutic agents, high dose methotrexate doses followed by leucovorin rescue may be effective in prolonging relapse-free survival in patients with non-metastatic osteosarcoma. Methotrexate levels are monitored to assess toxicity.
Performing Laboratory
med fusion
