Microsampling techniques and patient-centric therapeutic drug monitoring of immunosuppressants
Kocur & Pawiński
The finding, in our words
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 paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
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 ↗
A validated LC-MS/MS method for everolimus using Mitra and Capitainer devices found excellent agreement between capillary microsamples and venous whole blood in 33 adult transplant recipients. The results showed high accuracy and negligible haematocrit effects, supporting the use of microsampling for decentralised therapeutic drug monitoring.
The authors observe that self-sampling devices for capillary blood are gaining traction as a patient-preferred alternative to venous collection, with one centre reporting a 15 percent reduction in laboratory test volumes when local collection was offered. They argue that successful integration into total laboratory automation requires addressing cost, transport regulations and sample volume adequacy while ensuring robust device design and seamless workflow compatibility.
Poland & Cobbaert, Clinical chemistry and laboratory medicine (paywalled) · source ↗