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Test Code RAVU Ravulizumab, Serum

Reporting Name

Ravulizumab, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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)


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.


Specimen Type

Serum

Specimen 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

Interpretation

Target trough therapeutic concentrations (immediately before next infusion) of ravulizumab are expected to be above 175 mcg/mL for paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.

 

Pharmacodynamic studies of complement blockage may also be recommended for patients undergoing therapy.

Day(s) Performed

Wednesday

Report Available

3 to 9 days

Test 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

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RAVU Ravulizumab, S 97184-6

 

Result ID Test Result Name Result LOINC Value
609420 Ravulizumab, S 97184-6