Biological Therapy Monitoring

QEUH Infliximab and Adalimumab Service

UPDATED MARCH 2021

Since December 2017 the Scottish Biologic Drug Monitoring Service has been delivered from the Biochemistry Dept. within the Lab Medicine Building on the Queen Elizabeth University Hospital site, Glasgow. The service currently delivers Infliximab and Adalimumab levels and their respective total anti-drug antibodies (ADA) for optimising care predominantly in gastroenterology patients with inflammatory bowel disease. The service attained UKAS accreditation (2019) and is working with IMMQAS and others to improve the EQA understanding for drug and ADA assays. The service uses both WHO standards for drug levels and a patient pool sample for ADA assay to monitor performance. It is involved in sample exchange with other laboratories.

The service employs a reflex ADA testing strategy based on drug level result. When a drug level result is within or higher than the therapeutic target range, and when ADA level has previously been undetectable, reflex ADA testing is not routinely performed. Since the introduction of reflex ADA testing approximately 50% adalimumab samples and 37% infliximab samples have not had a reflex ADA test performed. There may be some clinical scenarios where ADA titres are desirable even when drug level results are therapeutic. Requests for additional ADA testing should be indicated clearly at the time of test request or can be arranged by contacting the lab directly.

During 2019 there were 2821 Infliximab and 2920 Adalimumab samples analysed from health boards across Scotland.

TDM tests should requested according to local biochemistry/immunology laboratory requirements. The previously used paper request forms are no longer required. Local teams are encouraged to collate data related to TDM use and outcomes as this may be required to sustain future rounds of service funding.

Specific Rheumatology guidance on monitoring has been produced:

Rheumatology guidance

Specific Gastroenterology guidance on monitoring has been produced, along with a quick reference guide:

Gastroenterology Guidance

Gastroenterology Quick Reference Guide

Vedolizumab drug level and antibody testing

Vedolizumab drug level testing is now available. The utility of testing drug and anti-drug antibodies for vedolizumab has yet to be fully ascertained. Target drug levels for vedolizumab have not been clearly established. The current evidence is covered in these articles:-

https://www.sciencedirect.com/science/article/pii/S1542356518304026

https://doi.org/10.1093/ecco-jcc/jjz041

https://dx.doi.org/10.1186%2Fs12916-019-1323-8

Vedolizumab testing is not part of the nationally commissioned TDM service. The cost per sample is £20.

In order to gather clinical data regarding the benefits of vedolizumab drug level testing, please complete and enclose a completed request form with each sample. This information will be used to try and secure UKAS accreditation for vedolizumab drug level testing.

Vedolizumab request

Further Information

For queries about the service please contact the QEUH Biochemistry Laboratory on 0141 354 9060