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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

Method Name

RISA: Liquid Chromatography Mass Spectrometry (LC-MS)

RISAB: Electrochemiluminescent-Bridging Immunoassay (ECLIA)

Reporting Name

Risankizumab QN with Antibodies, S

Specimen Type

Serum

Specimen 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 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

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.