Prometheus Anser UST
Test Mnemonic
ANSUST
CPT Codes
- 80299 - QTY (1)
- 82542 - QTY (1)
Includes
- Serum ustekinumab (UST) concentration
- Antibodies to ustekinumab (ATU) concentration
Performing Laboratory
Prometheus
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Serum | SST (Gold) | Refrigerated | Ship using cold pack |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Serum | No additive (Red) | Refrigerated | Ship using cold pack |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Adult patients | ||||
| 0.5 mL | Pediatric patients |
Stability
| Environmental Condition | Description |
|---|---|
| Refrigerated | 9 days |
| Ambient | 7 days |
| Frozen | Unacceptable |
Days Performed
Varies
Turnaround Time
4 - 5 days
Methodology
| Name | Description |
|---|---|
| High Performance Liquid Chromatography (HPLC) |
Clinical Info
Serum concentrations of ustekinumab (UST) may vary among equally dosed patients, which can ultimately affect patient outcomes. Some patients may develop immunogenicity to UST by producing antibodies to ustekinumab (ATU), and the presence of persistent ATU has been observed to substantially reduce serum concentrations of UST. The quantitative measurement of UST and ATU levels in serum provides clinicians with valuable information to help them gain a better understanding of the factors that may be affecting a patient’s loss of response. The Prometheus Anser UST test is a next generation and more sensitive quantitative monitoring assay that allows healthcare providers to measure and monitor serum UST and ATU levels at any time during therapy. Incorporating therapeutic drug monitoring may clarify what factors are contributing to a patient’s loss of response and help guide treatment decisions by providing information to help determine an appropriate course of action.