Liquid chromatography-tandem mass spectrometry for therapeutic drug monitoring of immunosuppressants and creatinine from a single dried blood spot using the Capitainer® qDBS device
Deprez et al.
The finding, in our words
Deprez et al. validated LC‑MS/MS methods for four immunosuppressants and creatinine from a single 10 μL quantitative dried blood spot. With biases under 10 % and CVs below 8 %, the approach enables accurate patient‑centric therapeutic drug monitoring from capillary blood at home, mitigating the haematocrit effect through volumetric collection.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Microsampling, particularly VAMS and quantitative DBS, can enable patient-centric therapeutic drug monitoring of immunosuppressants after transplantation, allowing home self-sampling and long-term monitoring when patients live far from transplant centres. These volumetric dried formats have largely overcome the haematocrit effect and sample heterogeneity that limit conventional dried blood spots.
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.
Microsampling enables less invasive, patient-centric self-collection of capillary blood for remote monitoring of metabolites and lipids, overcoming conventional venipuncture constraints. Recent device innovations address dried blood spot limitations, particularly haematocrit and volume variations, expanding decentralised applications in population health, drug discovery and multi-omics research.
An IQ Consortium position paper from sponsor scientists positioning patient-centric sampling as the enabling technology for decentralised trials, and stating that a bridging study against conventional sampling “has quickly been established as a regulatory expectation”.
Maass et al., Clinical and Translational Science · source ↗
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 ↗