2023 · Expert review of clinical pharmacology · paywalled
Dried blood spot sampling for therapeutic drug monitoring: challenges and opportunities
Müller et al.
The finding, in our words
Dried blood spot sampling enables minimally invasive capillary collection for therapeutic drug monitoring with room‑temperature stability, but hematocrit effects and venous‑capillary concentration differences require careful validation. Standardised guidelines have improved assay quality, and novel devices that mitigate these limitations will support broader clinical implementation.
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 matched clinical samples from rheumatoid arthritis, VAMS and DBS showed strong agreement for methotrexate polyglutamates (slopes 0.95-1.07; bias within -4.21% to 0.36%; SRCC ≥ 0.969), with up to 100% of total MTXPG results within ±20% limits; capillary microsampling agreed closely with whole blood but differed from red blood cells, indicating matrix-specific differences that must be accounted for when interpreting against RBC-based reference values.
Kocur et al., International journal of molecular sciences · source ↗
The study found a dried blood spot method for ustekinumab was linear from 3 to 12 mg/L with inter-day accuracy of 90.1 to 106%, enabling reliable capillary blood measurement for remote monitoring; the authors note the single-centre design.
A 2025 review maps 28 microsampling devices, from dried spots and volumetric absorptive tips to upper-arm liquid capillary collectors, and names what a laboratory must control before their results are used: the haematocrit effect in non-volumetric dried samples, interstitial fluid from finger milking, volume, haemolysis and transport stability. Regulators on both sides of the Atlantic ask for the same two things, a device the patient can use safely and a sample fit for the test.
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.
Paniagua-González et al., Journal of pharmaceutical and biomedical analysis (paywalled) · source ↗