2020 · J. Pharmaceutical and Biomedical Analysis · paywalled
Opportunities and obstacles for microsampling techniques in bioanalysis: special focus on DBS and VAMS
Londhe & Rajadhyaksha
The finding, in our words
A review contrasting the formats, framing the haematocrit effect, non-uniform spreading and homogeneity limits of DBS as the problems volumetric sampling is designed to solve.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.
The study validated an LC-MS/MS method for eight antiepileptic drugs and two metabolites in dried blood spot and VAMS formats, with satisfactory analytical performance and stability, and was the first to include the oxcarbazepine metabolite DHCB. In 80 paired patient samples, microsampling concentrations showed promising correlation with plasma, supporting decentralised therapeutic drug monitoring of antiepileptic treatment.
A review of 39 studies found that dried blood spot and volumetric absorptive microsampling show promising results for therapeutic drug monitoring of oral targeted anticancer drugs. The authors state that external validation remains crucial to confirm reliability, citing haematocrit effects and sample stability as key challenges.
This study compared four dried blood spot devices for glucocorticoid detection, finding that the Mitra VAMS device offered the best combination of analytical recovery and user usability, whilst the HemaXis DB10 showed the least bias compared to whole blood.