Ravulizumab, Serum
Use
Ravulizumab is used for therapeutic drug monitoring to assess the response to therapy and optimize dosage for patients requiring a specific monoclonal antibody concentration. It helps evaluate the need for dose escalation or de-escalation, and to monitor patients above a specific concentration to improve odds of clinical response. This test also supports the assessment of potential dose de-escalation or discontinuation during remission states. However, it should not be used as the sole basis for diagnosis or therapeutic decisions.
Special Instructions
It requires careful coordination for specimen collection, including potential discontinuation of certain medications (like natalizumab) weeks ahead. The test involves collecting serum samples and is best drawn immediately before the next scheduled dose.
Limitations
The test results should be interpreted within the clinical context. During transition from eculizumab to ravulizumab, results may reflect both antibodies, requiring cautious interpretation. Active concurrent therapy with natalizumab could interfere with results. This test does not differentiate between eculizumab and ravulizumab.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 97184-6
- 97184-6
Result Turnaround Time
3-9 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red top (preferred), Serum gel (acceptable); submission in plastic vial
Collection Instructions
Draw blood immediately before next scheduled dose. Immediately place the tube on wet ice, allow clotting, centrifuge at 4°C, aliquot serum into a plastic vial, and freeze within 30 minutes. If not frozen immediately, keep on dry ice.
Patient Preparation
Consider discontinuing natalizumab, if prescribed, at least 4 weeks prior to specimen collection unless otherwise directed by a healthcare provider.
Storage Instructions
Frozen (preferred), Ambient, or Refrigerated for up to 28 days.
Causes for Rejection
Gross hemolysis and gross lipemia are causes for rejection; gross icterus is acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 28 days |