2018 · British journal of clinical pharmacology · paywalled
Therapeutic drug monitoring of tacrolimus and mycophenolic acid in outpatient renal transplant recipients using a volumetric dried blood spot sampling device
Zwart et al.
The finding, in our words
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.
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.
This review surveys published LC-MS/MS methods that use dried blood microsampling for therapeutic drug monitoring of immunosuppressants in transplantation, chemotherapy and autoimmune disease, finding that volumetric dried blood samples can replace conventional venous draws for home sampling and improve patient quality of life. The authors discuss pre-analytical considerations, clinical applicability, cost-effectiveness, harmonisation gaps and patient perception, concluding that obstacles to routine clinical implementation remain despite growing methodological maturity.
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.
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.