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Infliximab Drug Levels

Blood Sciences Test


SPECIMEN

Serum

SPECIAL INSTRUCTIONS

Trough level recommended (immediately before the next dose is due).

TEST COST (NHS REFERRALS)

£29.50 per test

UNITS

mg/L

MEASURING RANGE

Lower limit of measuring range = 0.8 mg/L

Upper limit of measuring range = 45 mg/L

INTERNATIONAL STANDARDISATION

This Infliximab drug level assay is aligned to the 1st international infliximab standard NIBSC 16/170.

TEST USAGE

Managing inflammatory bowel disease patients with anti-TNF biological medicines such as Infliximab is challenging. Patients may respond well to treatment initially, only to encounter loss or response further ahead in their treatment pathway. Others may not respond to treatment at all. One approach to potentially improve outcomes for patients on Infliximab is to measure trough drug levels and to determine if patients have developed antibodies to the drug. However, drug level and antibody testing will only be useful if it actually creates positive outcomes for patients. The challenge lies in optimising when these analyses take place and how best to interpret the data in making clinical decisions that benefit patients.

RESULT INTERPRETATION

  • A week 14 infliximab drug level of 7mg/L is associated with remission at weeks 14 and 54 (1).

If you have any further enquiries please contact the duty biochemist by email: rde-tr.biochem@nhs.net. Further help with interpretation of infliximab drug and anti-drug antibody results can be found here: Anti TNF monitoring guidance 

FREE OF CHARGE TESTING FOR SELECTED INFLIXIMAB BIOSIMILARS

We have demonstrated that the infliximab drug level assay measures the biosimilar drugs in the same manner as the parent drug. We offer a companion diagnostics service with free of charge infliximab drug and antibody testing for the following infliximab biosimilar agents:

  • Remsima
  • Inflectra
  • Flixabi
  • Zessly

(Please note; it is important to contact the relevant pharmaceutical company to ensure you meet the relevant terms and conditions of this service.)

AVAILABILITY

Local test

TURNAROUND TIME

10 working days

Can be added on to an existing request, stable in whole blood and serum for 7 days at room temperature (2).

REFERRALS

We welcome referrals for Anti TNF monitoring. If you are a new requestor please complete the following form: New requestor form

Our Quality Statement for referred work can be found here :  Quality statement May 2019 (374 downloads)

REFERENCES

  1. Kennedy, N. A., Heap, G. A., Green, H. D., Hamilton, B., Bewshea, C., Walker, G. J., … Bouri, S. (2019). Predictors of anti-TNF treatment failure in anti-TNF-naive patients with active luminal Crohn’s disease: a prospective, multicentre, cohort study. The Lancet Gastroenterology & Hepatology. doi:10.1016/s2468-1253(19)30012-3
  2. Perry M, Bewshea C, Brown R, So K, Ahmad T, McDonald T. Infliximab and adalimumab are stable in whole blood clotted samples for seven days at room temperature. .Ann Clin Biochem.2015 Mar 16. pii: 0004563215580001. [Epub ahead of print]
Specimen Labelling Procedure
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