AU/mL (arbitrary units per mL)
Interpretation of Infliximab antibody levels
This assay measures TOTAL Infliximab Antibody concentration.
Total Antibody concentration >/= 10 AU/mL is positive. The distribution for 3760 positive results is as follows:
|Centile range||Total Infliximab antibodies (AU/mL)|
|0 – 5th||10 – 11|
|6th – 25th||12 – 18|
|26th – 50th||19 – 40|
|51st – 75th||41 -115|
|76th – 95th||116 – 400|
The top of the measuring range is 400 AU/mL. This corresponds to the 95th Centile
For further interpretation please see: Anti TNF monitoring guidance
The ELISA immunoassay method used for infliximab total anti-drug antibody measurement at Exeter Blood Sciences laboratory uses a streptavidin-biotin system in its design. If patients are taking large doses of Biotin (Vitamin B7), there is potential for interference in this assay with a possibility of lowered results when biotin concentration >318 nmol/L.
For further information on biotin interference please see: https://www.exeterlaboratory.com/biotin-alert-potential-assay-interference/
Can be added on to an existing request
We welcome referrals for Anti TNF 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: Infliximab and Anti-Infliximab Antibodies – further information
Specimen Labelling Procedure