QEUH Infliximab and Adalimumab Service
From Monday 11th December, the Adalimumab and Infliximab service will be provided by the Biochemistry department at the Queen Elizabeth University hospital. We will measure these drugs using an immunoassay based method from Promonitor. This method is different to that used by Exeter, your current user provider. For adalimumab result provided by QEUH will be <10% lower than those provided by Exeter. For infliximab, results provided by QEUH will be two fold higher than Exeter. The therapeutic range for adalimumab is 5-10ug/ml . For infliximab the therapeutic range is 2-8ug/ml. (or mg/l) The drug levels of Infliximab will be reported with upper limit as above 12ug/mL. (The correlation for both assays show r2 > 0.9).
The antidrug antibody for both measurements are more complex. There is debate as to whether total anti-drug antibody or free anti-drug antibody is better. In light of this, we will report Immundiagnostik total anti-drug antibody concentrations – i.e. identical to Exeter’s current reported method. In those who have increased levels, a second Promonitor free antidrug antibody will be performed.
Initial work on several hundred samples has shown that the free antidrug assay picks up far fewer positive cases (<25%). Where the drug level is lower, there is a good case to increase the biological agent and correlate clinical response with a further repeat sample later. Over the first few months, the information will be collated as we would seek clinical feedback.
Thereafter, we will be looking at other biological agents especially Etanercept if there are adequate requests.
Complete clinical details to enable audit of these new assays are essential. In NHSGGC Trakcare will shortly be updated to enable these detailed to be entered.
Paper forms to provide relevant details as a supplement to the request have been produced:
For queries about the service please contact the QEUH Biochemistry Laboratory on 0141 354 9060