Biological Fluid Microsampling for Therapeutic Drug Monitoring: A Narrative Review
Cafaro et al.
The finding, in our words
This narrative review evaluates microsampling devices for therapeutic drug monitoring, concluding that techniques such as volumetric absorptive microsampling and dried blood spots offer reliable, less invasive alternatives to venous sampling when paired with high-sensitivity mass spectrometry, which supports implementation in routine clinical practice.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
The review finds that volumetric absorptive microsampling addresses the haematocrit bias inherent in dried blood spots, making it suitable for therapeutic drug monitoring, but emphasises that each microsampling technique presents distinct analytical and logistical challenges that must be weighed for decentralised deployment.
The study validated an LC-HRMS method for measuring breast cancer drugs in plasma, urine, VAMS and oral fluid, showing that all matrices except oral fluid for certain drugs can support decentralised therapeutic drug monitoring. VAMS and oral fluid faced practical challenges in collection due to patient conditions, but the method enables patient-centric monitoring with dried blood and other self-collected samples.
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.
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.
This review establishes that microsampling across blood, saliva, urine and stool matrices offers validated workflows and regulatory recognition for human biomonitoring comparable to conventional methods. It finds that these decentralised approaches enhance participant acceptability and enable screening in remote or low-resource settings.