Test Code RISAP Risankizumab Quantitation with Antibodies, Serum
Specimen Required
Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose (trough specimen).
2. Within 2 hours of collection, centrifuge, and aliquot serum into a plastic vial.
Useful For
Evaluation of patients with limited primary (initial) response to or secondary loss of response to risankizumab
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
RISA | Risankizumab, S | Yes | Yes |
RISAB | Risankizumab Ab, S | No | Yes |
Testing Algorithm
For more information see Ulcerative Colitis and Crohn Disease Therapeutic Drug Monitoring Algorithm.
Special Instructions
Method Name
RISA: Liquid Chromatography Mass Spectrometry (LC-MS)
RISAB: Electrochemiluminescent-Bridging Immunoassay (ECLIA)
Reporting Name
Risankizumab QN with Antibodies, SSpecimen Type
SerumSpecimen Minimum Volume
0.75 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Heat-treated specimens | Reject |
Reference Values
RISANKIZUMAB QUANTITATION:
Risankizumab lower limit of quantitation =1.0 mcg/mL
RISANKIZUMAB ANTIBODIES:
Antibodies to risankizumab: <20.0 ng/mL
Interpretation
The optimal therapeutic serum concentration of risankizumab associated with favorable outcomes in Crohn disease is not known at this time. The current recommendation is to use the lowest dosing regimen that maintains response. According to the package insert, concentrations of risankizumab at steady state ranged from 4.1 mcg/mL (trough) to 14 mcg/mL (peak) at 180 mg dosing and 8.1 mcg/mL (trough) to 28 mcg/mL (peak) at 360 mg dosing. Steady state is achieved 28 weeks after initiation of therapy for the dosing regimen in Crohn disease.
The presence of detectable anti-risankizumab antibodies may be associated with increased risankizumab clearance and lower circulating concentrations of risankizumab in serum. Low trough concentrations of risankizumab may be correlated with loss of response to the drug.
Day(s) Performed
Weekly
Report Available
2 to 9 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
80299
82397
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RISAP | Risankizumab QN with Antibodies, S | 105194-5 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
621304 | Risankizumab, S | 105041-8 |
621769 | Risankizumab Ab, S | 105195-2 |
621812 | RISAB Interpretation | 59462-2 |
Forms
If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen.