2023 · Archives of pathology & laboratory medicine · paywalled
Application of a Fully Automated Dried Blood Spot Method for Therapeutic Drug Monitoring of Immunosuppressants: Another Step Toward Implementation of Dried Blood Spot Analysis
Deprez & Stove
The finding, in our words
Automated dried blood spot analysis achieved clinical and analytical acceptance criteria for tacrolimus, sirolimus, everolimus and cyclosporin A after haematocrit correction. This validates a method that could enable decentralised, patient-centric therapeutic drug monitoring for transplant recipients.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
A new LC-MS/MS method quantifies four immunosuppressants from one 3.2 mm dried blood spot using cold-induced phase separation, achieving accurate results and favourable interchangeability with a certified whole blood method in 120 paired clinical samples, supporting decentralised therapeutic drug monitoring.
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.
In AML and CLL, 91% of VAMS venetoclax results fell within 20% of plasma after individualised haematocrit correction; in home sampling, 18 of 21 patients self-sampled independently and 76% of returned samples were analysable, which shows home microsampling is workable, though the authors ask for multicentre validation.
In lung and renal transplant recipients, VAMS sampling with LC-MS/MS quantification of mycophenolic acid and tacrolimus showed good linearity and accuracy, and with a haematocrit-adjusted conversion formula achieved clinical agreement in most samples; tacrolimus did not require haematocrit correction. The approach is virtually painless and enables richer sampling for more accurate drug exposure estimates, supporting decentralised therapeutic drug monitoring.