8 days
Enzyme-immunoassay
µg/mL
The target drug concentration to be achieved may vary: it depends on the indication (gastroenterology, rheumatology or other), the phenotype of the disease, the activity of the disease, the phase of therapy (induction, post-induction, maintenance or prolonged remission) and the interindividual variations. The values given are therefore for INDICATIVE purposes only and should be interpreted with caution.
Inflammatory bowel disease: Irving et al., 2022. Expert consensus statement according to Cheifetz et al., 2021.
Induction (Week 4): 8-12 µg/mL
Post-induction (Week 12): 8-12 µg/mL
Maintenance: 8-12 µg/mL
Rheumatology: Krieckaert et al., EULAR 2022
Rheumatoid arthritis: 2-8 µg/mL
Axial spondyloarthritis: 2,5-8 µg/mL
Psoriatic arthritis: 1-8 µg/mL
There is currently no consensus on the clinically relevant anti-drug antibody threshold to define a high titer. By experience, a value of less than 100 ng/mL may be indicative of transient or low-affinityantibodies, requiring a recheck 3 months later. A value greater or equal to 100 ng/mL, on the other hand, would suggest patient immunization, a reduction in circulating drug and a loss of treatment efficacy.
(Berger et al., 2022) Recommendations for monitoring biotherapies include: loss of clinical response to biotherapies, drug optimization, change of drug class, addition of an immunosuppressant, dose de-escalation or treatment discontinuation.
**** Caution: method and reference value changed on 20/06/25