The performance of five different dried blood spot cards for the analysis of six immunosuppressants
Koster et al.
The finding, in our words
The study compared five dried blood spot card types for therapeutic drug monitoring of six immunosuppressants and found that haematocrit and drug concentration significantly affect extraction recovery, with card performance differing most at extreme values. This matters because evaluating DBS card performance before analytical method validation is essential for accurate immunosuppressant measurement in decentralised care.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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 ↗
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.
Automated dried blood spot analysis achieved clinical and analytical acceptance criteria for tacrolimus, sirolimus, everolimus and cyclosporin A after haematocrit correction. This validates a method that could enable decentralised, patient-centric therapeutic drug monitoring for transplant recipients.
Deprez & Stove, Archives of pathology & laboratory medicine (paywalled) · source ↗
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.
Microsampling reduces sample volume, invasiveness, logistics and biohazard risk while improving stability and enabling at-home self-sampling, yet clinical adoption remains slow and requires standardisation and harmonisation to realise its patient-centric and decentralised potential.
Thangavelu et al., Analytical science advances · source ↗