2020 · Current environmental health reports · paywalled
Little to Give, Much to Gain-What Can You Do With a Dried Blood Spot?
McClendon-Weary et al.
The finding, in our words
Dried blood spots provide a minimally invasive, low-volume and cost-effective approach for measuring pollutants, genetic markers, clinical biomarkers and drug adherence in population studies, yet the haematocrit effect introduces a significant error in concentration assessment, meaning further validation is essential for decentralised diagnostic use.
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.
Levens et al., Clinical Pharmacokinetics (paywalled) · source ↗
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.
Juan et al., Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques · source ↗
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.
Huhn & Scherf-Clavel, Therapeutic drug monitoring (paywalled) · source ↗
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.
Capillary dried blood spots, after haematocrit-dependent conversion, showed good agreement with plasma for 25-hydroxyvitamin D quantification, with 90 per cent of results within 20 per cent of plasma and substantial to almost perfect agreement in status classification, supporting reliable home self-collection for large-scale vitamin D monitoring.
Heughebaert et al., Clinical chemistry and laboratory medicine (paywalled) · source ↗