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.