CPT Code: 84431, 82570
Order Code: C922
Includes: 11-Dehydrothromboxane B2 and Urine Creatinine
ABN Requirement: No
Synonyms: 11-Dehydrothromboxane B2; 11dhTXB2
Specimen: Urine
Volume: 4.0 mL (per tube)
Minimum Volume: 3.0 mL (per tube)
Container:
Gray Top BD C&S Vacutainer® Preservative Tube
OR
Cherry Red-Yellow Top BD Vacutainer® Preservative Tube AND Plain Yellow Top Tube
Collection:
Gray Top Tube:
- Collect urine sample according to standard protocols.
- Transfer aliquot from a clean urine cup into the Gray Top tube using the vacutainer transfer device included with the Gray Top tube.
- Gently invert the tube 8-10 times.
- Label sample according to standard protocols.
OR
Cherry Red-Yellow Top Tube:
- Collect urine sample according to standard protocols.
- Transfer aliquot from a clean urine cup into the Cherry Red-Yellow Top tube using the vacutainer transfer device included with the Cherry Red-Yellow Top tube.
- Gently invert the tube 8-10 times.
- Label sample according to standard protocols.
Plain Yellow Top Tube:
- Collect urine sample according to standard protocols.
- Transfer aliquot from a clean urine cup into the Yellow Top tube using the vacutainer transfer device included with the Yellow Top tube.
- Label sample according to standard protocols.
Transport: Store urine at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.
Stability:
11dhTxB2 and Urine Creatinine (Gray Top Tube):
Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 14 days
Frozen (-20°C): 90 days
11dhTxB2 (Cherry Red-Yellow Top Tube):
Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 14 days
Frozen (-20°C): 90 days
Urine Creatinine (Plain Yellow Top Tube):
Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 14 days
Frozen (-20°C): 6 months
Causes for Rejection: Specimens other than urine, urine collected in incorrect tube type, improper labeling; samples not stored properly; samples older than stability limits, excessive sediment, blood, insoluble materials
Methodology: Immunoassay (IA), Enzymatic, Calculation
Turn Around Time: 1 to 5 days
Reference Range (Status of Aspirin Effect):
| Age | 11-dhTXB2/Creatinine (pg/mg Cr) |
| All Ages | ≤1500 |
Clinical Significance: Aspirin (which inhibits platelet cyclooxygenase) reduces the risk of thrombosis in cardiovascular disease by impairing platelet function. Patients who do not respond to the platelet inhibitory effects of aspirin are designated as “aspirin resistant”. The measurement of 11-dhTXB2 in urine (the principal metabolite of platelet cyclooxygenase derived thromboxane B2) may be used in individuals to assess aspirin effect and responsiveness to therapy.
Limitations: Test results may be affected by the ingestion of alcohol, green tea extract, chocolate, omega-3 fatty acids, ibuprofen, statins, or COX-2 inhibitors. Testing should not be performed on individuals suffering from urinary tract infections, severe liver disease or end stage renal disease. It is not known how treatment with oral anticoagulants, glycoprotein IIb/IIIa inhibitors, clopidogrel, or heparin will affect test results.
Additional Information: It is important to interpret the results with regard to patient history and lifestyle, in particular medications and supplements, as well as other risk factors. The test should not be used to measure return of platelet function after discontinuation of aspirin therapy.
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.