Advisory Information

This test includes both quantitation and antibody testing on all specimens. Therapeutic thresholds for vedolizumab optimal concentrations associated with good outcomes are not well established. The American Gastroenterology Association (AGA) does not have a formal guideline on optimal thresholds for vedolizumab at this time.

If there is a known justification for performing both quantitation and antibody levels, this is the correct test to order. If there is not a known reason to perform the antibodies component, order VEDOL / Vedolizumab Quantitation with Reflex to Antibodies, Serum. VEDOL begins with quantitation and when quantitation results are 15.0 mcg/mL or less, testing for antibodies to vedolizumab will be performed.

Specimen Required

1. Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

2. Nivolumab (Opdivo) must be discontinued at least 4 weeks prior to testing for vedolizumab quantitation in serum.

Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1.5 mL

Collection Instructions:

1. Draw blood immediately before next scheduled dose (trough specimen).

2. Centrifuge within 2 hours of draw.