Test Catalog

Test ID: VEDOZ    
Vedolizumab Quantitation with Antibodies, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Assessing the unexpected loss of response to therapy with vedolizumab over time


An aid to achieving desired serum levels of vedolizumab

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, vedolizumab quantitation and testing for antibodies to vedolizumab will always be performed.


This test includes both quantitation and antibody testing on all specimens. The therapeutic thresholds for vedolizumab and 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.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Vedolizumab (Entyvio) is a humanized monoclonal antibody directed against integrin alpha-4 beta-7. Blocking the alpha-4 beta-7 integrin results in a gut-selective anti-inflammatory response. The drug is FDA-approved for the treatment of adult patients with moderately to severely active ulcerative colitis or Crohn disease. Although optimal therapeutic concentrations of vedolizumab are not well known, Mayo Clinic Gastroenterologists are working to correlate drug concentrations with patient outcomes. Vedolizumab testing will assess the patients loss of response to therapy, similar to therapy received using tumor necrosis factor (TNF) inhibitors, such as infliximab and adalimumab. Some patients on vedolizumab may develop antibodies to vedolizumab (ATV) over time. In clinical trials, approximately 4% of patients treated with vedolizumab were positive for ATV at any time and 1% or less were persistently positive. Therefore, simultaneous testing for measurement of ATV is recommended. ATV uses a bridging immunoassay on an electrochemiluminescence (Mesoscale Discovery) platform.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


Vedolizumab lower limit of quantitation=2.0 mcg/mL



Antibodies to vedolizumab: <9.8 ng/mL

Interpretation Provides information to assist in interpretation of the test results

Data in the literature with association of vedolizumab trough levels and improved outcomes is still scarce. The limit of quantitation of the test is 2.0 mcg/mL. In a retrospective Mayo Clinic study conducted from 2016-2017 with 171 patients (62% Crohn disease, 31% ulcerative colitis, and 7% indeterminate colitis), the median vedolizumab trough concentration was 15.3 mcg/mL. Minimum trough (immediately before next infusion) therapeutic concentrations of vedolizumab are expected to be above 15 mcg/mL.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Patients actively undergoing therapy with both vedolizumab and nivolumab (extremely rare scenario) should not have their therapeutic vedolizumab concentration assessed using this test. If the patient has taken nivolumab in the past, they should wait for 4 weeks after therapy with nivolumab has ended before being tested for vedolizumab quantitation using this method.


The presence of high concentrations of vedolizumab might inhibit the antibodies to vedolizumab (ATV) assay yielding false-negative results. In patients with concentrations of vedolizumab greater than 15.0 mcg/mL, the presence of an ATV is of little clinical significance.


Samples containing more than 100 ng/mL biotin (vitamin B7) may interfere with ATV (in the form of depressed signal) for VEMAB / Vedolizumab Antibodies, Serum. .


Clinical management decisions for patients receiving vedolizumab treatment should not be based solely on quantitation of vedolizumab and assessment of ATV. Test results must be interpreted within the clinical context of the patient.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Willrich MA, Murray DL, Barnidge DR, et al: Quantitation of infliximab using clonotypic peptides and selective reaction monitoring by LC-MS/MS. Int Immunopharmacol 2015 Sep;28(1):513-520

2. Katrangi W, Ladwig PM, Barnidge DR, et al: A-260 Vedolizumab Quantitation in Serum using SRM and micro LC-ESI-Q-TOF Mass Spectrometry. Clin Chem 2015;61

3. Ladwig PM, Barnidge DR, Willrich MA: Mass Spectrometry Approaches for Identification and Quantitation of Therapeutic Monoclonal Antibodies in the Clinical Laboratory. Clin Vaccine Immunol 2017 May 5;24(5)

4. Ladwig PM, Barnidge DR, Willrich MA: Quantification of the IgG2/4 kappa Monoclonal Therapeutic Eculizumab from Serum Using Isotype Specific Affinity Purification and Microflow LC-ESI-Q-TOF Mass Spectrometry. J Am Soc Mass Spectrom 2017 May;28(5):811-817

5. Feagan BG, Rutgeerts P, Sands BE, et al: Vedolizumab as Induction and Maintenance Therapy for Ulcerative Colitis. N Engl J Med 2013;Aug 22;369(8):699-710

6. Schulze H, Esters P, Hartmann F, et al: A prospective cohort study to assess the relevance of vedolizumab drug level monitoring in IBD patients. Scand J Gastroenterol. 2018:1-7

7. Al-Bawardy B, Piovezani Ramos G, Willrich MAV, et al: P167 Vedolizumab Trough Levels and Antibodies in Inflammatory Bowel Disease: Updated Initial Experience. Gastroenterology154:S89