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HelpOrder Code RAVU Ravulizumab, Serum
Ordering Guidance
To measure only serum concentration of ravulizumab, order RAVU / Ravulizumab, Serum.
To measure the impact of ravulizumab on complement activity and its effect on complement blockage, order RAVMP / Ravulizumab Monitoring Panel, Serum which measures the alternative pathway function.
Specimen Required
Patient Preparation: Suggest discontinuing natalizumab at least 4 weeks prior to testing for ravulizumab quantitation in serum. Patient should consult the healthcare provider who prescribed this drug to determine if discontinuation is an option. If not, ok to proceed with testing while taking natalizumab.
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Immediately after specimen collection, place the tube on wet ice.
3. After specimen has clotted on wet ice, centrifuge at 4° C and aliquot serum into a plastic vial.
4. Freeze specimen within 30 minutes of centrifugation. Specimen must be placed on dry ice if not frozen immediately.
Useful For
Assessing the response to ravulizumab therapy
Assessing the need for dose escalation
Evaluating the potential for dose deescalation or discontinuation of therapy in remission states
Monitoring patients who need to be above a certain ravulizumab concentration in order to improve the odds of a clinical response for therapy optimization
This test is not useful as the sole basis for a diagnosis or treatment decisions
Method Name
Liquid Chromatography Tandem Mass Spectrometry, High Resolution Accurate Mass (LC-MS/MS HRAM)
Reporting Name
Ravulizumab, SSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 28 days | |
| Ambient | 28 days | ||
| Refrigerated | 28 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
Lower limit of quantitation=5.0 mcg/mL
>175 mcg/mL-Therapeutic concentration for paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome
Method Description
Ravulizumab is extracted from serum and measured by liquid chromatography high-resolution accurate-mass mass spectrometry.(Unpublished Mayo method)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80299
Day(s) Performed
Wednesday
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.