Leading Edge 2022 Issue 2

www.alphalabs.co.uk 7 Are there any other advantages of using the four BÜHLMANN TDM assays? Most of our patients are children, therefore the amount of blood needed to perform a test is important. The Quantum Blue® assays only request a few microlitres of blood, which is perfect for children. In addition, having the result within one hour from blood taking is an improvement in the rapid result reporting. At the beginning of the TDM measurement some time ago, we occasionally had primary non responders or secondary non responders due to treatment failure. In these cases, we had to try to quickly run a test, that was performed reactively. Today, we have screened all our patients from rheumatology and gastroenterology, and we are able to perform proactive monitoring thanks to the Quantum Blue® assays. Because of the quick turnaround time, we have also started to sometimes test patients just before they are discharged from the hospital and ready to go back home. However, in our daily organisation of normal routine, we have setup a specific day once a week for TDM measurements. This is really appreciated by the clinicians. They know exactly when they will get their results. Despite this test agenda, we sometimes get additional samples to be tested on another day of the week. Today, with Quantum Blue® flexibility, we have the possibility to do so, knowing exactly the costs of running only one sample per day. „ The results of the method comparison between the ELISA technique and Quantum Blue® TDM showed highly comparable trough levels.” Which measurement algorithm do you follow? We have decided to run both serum levels and antibodies in parallel as it helps us and the clinicians to get the complete picture of the patient situation. If the serum levels are within the therapeutic window, the results are optimal and there is no need to additionally test for antibodies. Conversely, when drug is undetectable, the fact that we can measure the antibodies at the same time helps physicians to take a decision on the action needed. „ TDM with Quantum Blue® is a very valuable tool for the clinicians to decide on dose increase or decrease as well as drug class switches.” Would you be interested in new developments on the Quantum Blue® Reader? Today we are performing the four BÜHLMANN assays in our daily routine: Quantum Blue® Infliximab, Quantum Blue® Adalimumab, Quantum Blue® Anti-Infliximab and Quantum Blue® Anti-Adalimumab. I would say that TDM with Quantum Blue® is part of our routine use now and a very valuable tool for the clinicians to decide on dose increase or decrease, but also to support the strategy of within or in between class switch of drugs. If I would have a wish for the future, I would think that a rapid assay for the measurement of tocilizumab might be interesting for juvenile arthritis patients. We have tested an ELISA technique already but would be more interested in a rapid test. In addition, vedolizumab serum levels would be interesting and an anti-TNFCalibri method from capillary blood. For children, this would be very attractive. For more information, visit our website alphalabs.co.uk/tdm