Test ID RAVMP Ravulizumab Monitoring Panel, Serum
Ordering Guidance
To measure only serum concentration of ravulizumab, order RAVU / Ravulizumab, Serum.
Specimen Required
Patient Preparation:
1. Fasting preferred.
2. 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.
Supplies: Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: 2 Plastic vials
Specimen Volume: 2 mL in 2 plastic vials, each vial containing 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 sample has clotted on wet ice, centrifuge at 4° C and aliquot serum into two 5 mL plastic vials.
4. Freeze specimen within 30 minutes of centrifugation. Sample must be placed on dry ice if not frozen immediately.
Useful For
Monitoring of complement blockage by ravulizumab
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
Highlights
Ravulizumab is a therapeutic monoclonal antibody targeting complement C5 with a longer half-life than eculizumab. Monitoring the complete complement blockade by eculizumab has allowed personalized therapy in specific settings. Similar action is expected with ravulizumab. Ravulizumab has 4 different amino acids from eculizumab, which allow greater affinity for the FcRn immunoglobulin receptor and change the affinity of the molecule for C5.
Therapeutic drug monitoring of ravulizumab may be useful when patients need to be above a certain target or therapeutic threshold of the monoclonal antibody concentration to improve odds of a clinical response for therapy optimization or potential dose deescalation or discontinuation of therapy in remission states.
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
RAVU | Ravulizumab, S | Yes | Yes |
RAVUM | Ravulizumab Complement Blockage, S | No | Yes |
RAVIN | Ravulizumab Interpretation, S | No | Yes |
Method Name
RAVUM: Enzyme-Linked Immunosorbent Assay (ELISA)
RAVU: Liquid Chromatography Tandem Mass Spectrometry, High Resolution Accurate Mass (LC-MS/MS HRAM)
Reporting Name
Ravulizumab Monitoring Panel, SSpecimen Type
SerumSerum Red
Specimen Minimum Volume
1 mL in 2 plastic vials, each vial containing 0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen | 14 days | |
Serum Red | Frozen | 14 days |
Reference Values
RAVULIZUMAB COMPLEMENT BLOCKAGE:
≥46% normal
RAVULIZUMAB:
Lower limit of quantitation =5.0 mcg/mL
>175 mcg/mL: Therapeutic concentration for paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome
Day(s) Performed
Varies
Report Available
3 to 10 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80299
86161
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RAVMP | Ravulizumab Monitoring Panel, S | 101923-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
609500 | Ravulizumab Complement Blockage, S | 74520-8 |
609420 | Ravulizumab, S | 97184-6 |
619952 | Ravulizumab Interpretation | 59462-2 |