A device for dried blood microsampling in quantitative bioanalysis: overcoming the issues associated blood hematocrit
Spooner et al.
The finding, in our words
The cross-laboratory study showed a novel volumetric absorptive microsampling device for dried blood absorbed a consistent 10.6 μl sample across haematocrit values from 20 to 65 percent, with acceptable variation between six different laboratories. This overcomes a key limitation of traditional dried blood spot sampling where haematocrit affects sample volume, making the device suitable for reliable quantitative bioanalysis in decentralised settings.
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.
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.
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.
A liquid chromatography-tandem mass spectrometry method was successfully validated for measuring androstenedione, 17α-hydroxyprogesterone, and 11-ketotestosterone in dried blood samples collected via volumetric absorptive microsampling. The dried samples remained stable at room temperature for up to a week and after postal transit, and plasma concentrations could be reliably estimated from the microsamples when adjusting for haematocrit.
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.