Leading Edge 2022 Issue 2

6 LEADING EDGE - 2022-2 Successful Routine Use of Quantum Blue® Therapeutic Drug Monitoring (TDM) Assays in an Italian Children’s Hospital An interview with Dr. ssa Giuliana Cangemi This interview was conducted by BÜHLMANN with Dr ssa Giuliana Cangami - Head of the Chromatography and Mass Spectrometry Unit at the Central Laboratory of Analyses in Gaslini Intitute Pediatric Hospital in Genova, Italy. Can you introduce your organisation? In the Central Laboratory of Analyses in the Gaslini Institute Pediatric Hospital in Genova, one of the main tasks is to perform therapeutic drug monitoring (TDM). The laboratory specialises in the TDM of small molecules and for four years now, we have also been performing TDM for biologics. Most of the requests in the Central Laboratory of Analyses are coming from paediatricians. However, requests from external laboratories are also accepted and performed. It also happens that outsourced patients come to the Gaslini Institute with a prescription for the TDM tests. I would say that we had more requests from gastroenterologists when we initially started, but today rheumatologists are also keen to get TDM results for both, infliximab and adalimumab. „ The previously used ELISA method was time consuming but also not economically viable.“ Which technique do you use for TDM measurement and why did you choose this one? The first technique used for the TDM of the anti-TNFα such as infliximab and adalimumab was ELISA. This ELISA method was time consuming and also not economically viable when we had to perform a test including calibration and controls just for one or few patients. To avoid increasing the price of the assay, we had to wait to have enough samples to perform a batch. The price per patient was different depending on the number of patients tested per batch. This was also quite complicated to handle from an economical point of view. How did you introduce the BÜHLMANN Quantum Blue® TDM methods? Once we had been introduced to the rapid tests from BÜHLMANN Laboratories, we decided to perform a method comparison between the ELISA technique and both, Quantum Blue® Infliximab and Adalimumab rapid tests. The results were highly comparable for the trough levels between the Quantum Blue® assays and the ELISA technique, and the switch to the rapid assay was done quickly. At this time, only the rapid assays for trough levels were available and we decided to keep the ELISA method for the antibody measurement. This was not convenient, and we were ready to use the Quantum Blue® Anti-Infliximab and AntiAdalimumab as soon as they were available. As antibodies assays from the manufacturers are not standardised against each other, we did not perform a technical method comparison, but went straight for a clinical evaluation of the BÜHLMANN assays. The clinicians only require a qualitative measure of the antibodies as their need is to know whether immunisation is present or absent. Once they reviewed the good results of the evaluation, we directly switched from the ELISA to the Quantum Blue® assays and now we are using the full TDM portfolio from BÜHLMANN in our daily routine.