Application of non-contact hematocrit prediction technologies to overcome hematocrit effects on immunosuppressant quantification from dried blood spots
Deprez et al.
The finding, in our words
Near-infrared or ultraviolet/visible spectroscopy predicted haematocrit from dried blood spots, allowing correction of the haematocrit effect during automated analysis of immunosuppressants. For tacrolimus and cyclosporin A, correction was adequate; for sirolimus and everolimus, results improved though some bias remained. After correction, clinical acceptance limits (≥80% of samples within 20% of venous whole blood) were met for all four drugs, supporting accurate therapeutic drug monitoring from patient-collected samples.
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 ↗
A single VAMS run quantified two immunosuppressants plus creatinine with minimal haematocrit effect: combined drug-and-organ-function monitoring from one dried tip.
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 ↗