Original Title: Dosages immunologiques du tacrolimus et de la cyclosporine

Authors' objectives: A request for the addition of two new tests in the Répertoire québécois et système de mesure des procédures de biologie médicale (hereinafter referred to as the Répertoire) has been submitted to the Ministère de la Santé et des Services sociaux (MSSS) by the grappe Outaouais. The MSSS has mandated the Institut national d'excellence en santé et en services sociaux (INESSS) to assess the relevance of using immunological methods for measuring tacrolimus and cyclosporine blood levels. The Répertoire already includes assays performed using the reference method, liquid chromatography-tandem mass spectrometry (LC-MS/MS). It should be noted that the clinical relevance of therapeutic monitoring for these drugs is not addressed in this study.

Authors' results and conclusions: RESULTS (#1 POPULATIONAL DIMENSION): • Tacrolimus and cyclosporine are commonly administered to transplant recipients who require immunosuppression to prevent graft rejection. • These medications have a narrow therapeutic range and exhibit pharmacokinetic variability influenced by genetic and physiological factors. Regular blood tests are required to assess efficacy and safety, and to adjust dosing. (#2 CLINICAL DIMENSION): • Based on data from a single study, the measurement bias associated with ECLIA for cyclosporine, compared with LC-MS/MS, remains low and would not affect patient classification within the targeted therapeutic range. • When the bias is known and therapeutic ranges are adjusted accordingly, both immunological methods allow for appropriate classification of samples (subtherapeutic, therapeutic or supratherapeutic). (#3 SOCIOCULTURAL DIMENSION): • For clinical application, an immunological method for measuring immunosuppressive drugs should: – Be validated using commercial calibrators and patient samples; – Undergo cross-validation with peer laboratories using reference samples; – Demonstrate specificity for the parent compound with cross-reactivity to inactive metabolites assessed to quantify any imprecision in the assay result; – Be periodically reassessed through an external proficiency testing program (#4 ORGANIZATIONAL DIMENSION): • Quebec laboratories are experiencing a shortage of human resources, and personnel required to perform LC-MS/MS assays require training. • The equipment necessary to perform LC-MS/MS assays is not available in the regional grappe, unlike automated immunoassay analyzers. (#5 ECONOMIC DIMENSION): • The total cost of immunological assays proposed by the applicant laboratory is higher than that of LC-MS/MS assays. • Owing to reduced transportation costs, the use of immunological assays by the grappe Outaouais would result in cost reductions exceeding $139K over the first three years, for approximately 6,000 tacrolimus assays and 500 cyclosporine assays.

Authors' recommendations: INESSS recommends that the Minister of Health and Social Services introduce immunological blood assays for tacrolimus and cyclosporine into the Répertoire québécois et système de mesure des procédures de biologie médicale.

Project Status: Completed

Year Published: 2026

URL for published report: https://www.inesss.qc.ca/publications/repertoire-des-publications/publication/dosages-immunologiques-du-tacrolimus-et-de-la-cyclosporine.html

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Canada

Province: Quebec

Organisation Name: Institut national d'excellence en sante et en services sociaux

Contact Address: L'Institut national d'excellence en sante et en services sociaux (INESSS) , 2021, avenue Union, bureau 10.083, Montreal, Quebec, Canada, H3A 2S9;Tel: 1+514-873-2563, Fax: 1+514-873-1369

Contact Name: demande@inesss.qc.ca

Contact Email: demande@inesss.qc.ca

Copyright: L'Institut national d'excellence en sante et en services sociaux (INESSS)