Clinical Validation of Simultaneous Analysis of Tacrolimus, Cyclosporine A, and Creatinine in Dried Blood Spots in Kidney Transplant Patients
Veenhof et al.
The finding, in our words
Dried blood spot sampling demonstrated good agreement with venepuncture for tacrolimus and cyclosporine A, requiring no conversion formula, while creatinine needed a simple conversion factor. The method can replace conventional venous sampling for immunosuppressant monitoring in kidney transplant recipients, enabling home-based self-collection.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
VAMS microsampling found no significant difference from venous blood for tacrolimus in paediatric patients; samples were stable for 14 days, with average difference between paired at-home samples of 0.12 ± 0.94 ng/mL.
Clinical validation for tacrolimus and mycophenolic acid monitoring showed that while volumetric absorptive microsampling met analytical criteria after concentration correction, conventional dried blood spots achieved superior adherence to strict clinical criteria, sample quality, and cost efficiency without significant haematocrit bias.
Fingerprick dried blood spots showed analytical agreement with whole blood for sirolimus and everolimus in transplant patients, but only 77.3% and 61.5% of samples fell within the pre-defined 15% clinical relevance limit, missing the 80% target for both drugs. This suggests the method cannot yet replace conventional sampling for immunosuppressant monitoring without accepting less stringent clinical criteria, which constrains its use in decentralised diagnostics.
Volumetric dried blood spot sampling showed good agreement with conventional venous sampling for tacrolimus and mycophenolic acid concentrations in renal transplant recipients, with most concentrations and abbreviated AUCs falling within ±20% of conventional measures. Dosing recommendations differed on some occasions but the clinical impact was modest, suggesting home-based microsampling could support decentralised therapeutic drug monitoring with appropriate patient training.
The study validated a dried blood spot assay for five immunosuppressants on two LC-MS/MS systems, showing that haematocrit effects stayed within 15% across a clinically relevant range (0.23–0.48 l/l) without correction. Clinical validation confirmed that tacrolimus and cyclosporin A results from dried blood spots matched those from conventional whole blood, supporting home-based therapeutic drug monitoring without haematocrit adjustment.