Elisa Polledri1, Rosa Mercadante1, Chiara Ferraris Fusarini2, Rita Maiavacca2, Silvia Fustinoni1. 1. EPIGET - Epidemiology, Epigenetics, and Toxicology Lab, Department of Clinical Sciences and Community Health, Università degli Studi di Milano and Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. 2. Department of Clinical Chemistry and Microbiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
Abstract
RATIONALE: In the determination of immunosuppressive drugs cyclosporine A (CSA), tacrolimus (TARO), sirolimus (SIRO), and everolimus (EVE) in whole blood there is an open debate about which is the best assay between immunochemistry and liquid chromatography/tandem mass spectrometry (LC/MS/MS). This work is aimed to explore this topic, focusing on the use of updated assays and the analysis of a large number of samples. METHODS: A certified in vitro diagnostic kit coupled with a medical device LC/MS/MS was validated and applied to the analysis of 1192 blood samples of patients treated with immunosuppressive drugs. The results were compared with those obtained by immunoassays. RESULTS: The LC/MS/MS approach was found to provide linear, stable, precise, and accurate results, with lower limits of quantification of 12.5, 1.1, 1.2, and 1.2 μg/L for CSA, TACRO, SIRO, and EVE, respectively. With this method 80 samples were analysed and reported within a single work shift. A correlation was observed between the LC/MS/MS and immunoassay data, with Spearman correlation coefficients of 0.980 (n = 260) for CSA, 0.836 for TACRO (n = 562), 0.898 for SIRO (n = 113), and 0.904 for EVE (n = 257). Passing-Bablock regression showed the presence of constant and proportional biases for most of the drugs. A Blond-Altman graph showed differences between the assays, with immunoassays generally overestimating the drugs. CONCLUSIONS: The LC/MS/MS certified kit was validated for the detection of immunosuppressant drugs in whole blood and it provided a high-throughput method that is consistent with the requirements of clinical laboratories. The comparison of patient data between LC/MS/MS and up-dated immunoassays shows that a significant discrepancy still exists, especially for CSA and SIRO, confirming the greater specificity associated with use of the LC/MS/MS assay
RATIONALE: In the determination of immunosuppressive drugs cyclosporine A (CSA), tacrolimus (TARO), sirolimus (SIRO), and everolimus (EVE) in whole blood there is an open debate about which is the best assay between immunochemistry and liquid chromatography/tandem mass spectrometry (LC/MS/MS). This work is aimed to explore this topic, focusing on the use of updated assays and the analysis of a large number of samples. METHODS: A certified in vitro diagnostic kit coupled with a medical device LC/MS/MS was validated and applied to the analysis of 1192 blood samples of patients treated with immunosuppressive drugs. The results were compared with those obtained by immunoassays. RESULTS: The LC/MS/MS approach was found to provide linear, stable, precise, and accurate results, with lower limits of quantification of 12.5, 1.1, 1.2, and 1.2 μg/L for CSA, TACRO, SIRO, and EVE, respectively. With this method 80 samples were analysed and reported within a single work shift. A correlation was observed between the LC/MS/MS and immunoassay data, with Spearman correlation coefficients of 0.980 (n = 260) for CSA, 0.836 for TACRO (n = 562), 0.898 for SIRO (n = 113), and 0.904 for EVE (n = 257). Passing-Bablock regression showed the presence of constant and proportional biases for most of the drugs. A Blond-Altman graph showed differences between the assays, with immunoassays generally overestimating the drugs. CONCLUSIONS: The LC/MS/MS certified kit was validated for the detection of immunosuppressant drugs in whole blood and it provided a high-throughput method that is consistent with the requirements of clinical laboratories. The comparison of patient data between LC/MS/MS and up-dated immunoassays shows that a significant discrepancy still exists, especially for CSA and SIRO, confirming the greater specificity associated with use of the LC/MS/MS assay
Authors: Nicholas A Kolaitis; Daniel R Calabrese; Patrick Ahearn; Aida Venado; Rebecca Florez; Huey-Ling Lei; Karolina Isaak; Erik Henricksen; Emily Martinez; Tiffany Chong; Rupal J Shah; Lorriana E Leard; Mary Ellen Kleinhenz; Jeffrey Golden; Teresa De Marco; John R Greenland; Jasleen Kukreja; Steven R Hays; Paul D Blanc; Jonathan P Singer Journal: Am J Health Syst Pharm Date: 2019-12-02 Impact factor: 2.637