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Vedolizumab free anti-drug antibodies

Biochemistry Blood Sciences Test


Serum (1 ml)

Special instructions

Trough (pre dose) specimen required


AU/mL (Arbitrary Units per mL)

Test Price


NHS referral price

Test Usage

Immunogenicity to biologic drugs such as vedolizumab is a possible cause of treatment failure. The assay used to measure antibodies to Vedolizumab is drug-sensitive and can only detect ‘free’ antibodies that are unbound to drug, meaning that antibodies are unlikely to be detected in the presence of Vedolizumab drug. On this basis we will only perform anti-drug antibody analysis after the drug level has been analysed and is found to be <3.1 mg/L.

General Points

Free Antibody concentration >/= 10 AU/mL is positive.

Turnaround time

4 working weeks


We welcome referrals for Vedolizumab total Ab monitoring. If you are a new requestor please complete the following form: New requestor form. 

We now also have the option to use NPEx for referral requesting.

Further information about sample requirements for this test can be found here: Vedolizumab and Anti-Vedolizumab Antibodies – further information

Specimen Labelling Procedure

Specimen Labelling Procedure
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