Evaluation of sample extraction methods for minimizing hematocrit effect on whole blood analysis with volumetric absorptive microsampling
Ye & Gao
The finding, in our words
The study found that extracting VAMS dried blood samples with a one-to-one methanol and acetonitrile mixture gave more consistent recovery across haematocrit levels from 20 to 70% than methanol alone, with good linearity, accuracy and precision from 1 to 2000 ng/ml. This matters because haematocrit variation is a key source of bias in dried blood microsampling, and the optimised organic solvent extraction helps minimise that effect.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
In lung and renal transplant recipients, VAMS sampling with LC-MS/MS quantification of mycophenolic acid and tacrolimus showed good linearity and accuracy, and with a haematocrit-adjusted conversion formula achieved clinical agreement in most samples; tacrolimus did not require haematocrit correction. The approach is virtually painless and enables richer sampling for more accurate drug exposure estimates, supporting decentralised therapeutic drug monitoring.
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.
A liquid chromatography-tandem mass spectrometry method was successfully validated for measuring androstenedione, 17α-hydroxyprogesterone, and 11-ketotestosterone in dried blood samples collected via volumetric absorptive microsampling. The dried samples remained stable at room temperature for up to a week and after postal transit, and plasma concentrations could be reliably estimated from the microsamples when adjusting for haematocrit.
The study validated an LC-MS/MS method for eight antiepileptic drugs and two metabolites in dried blood spot and VAMS formats, with satisfactory analytical performance and stability, and was the first to include the oxcarbazepine metabolite DHCB. In 80 paired patient samples, microsampling concentrations showed promising correlation with plasma, supporting decentralised therapeutic drug monitoring of antiepileptic treatment.
The study developed and validated a rapid LC-MS/MS method for quantifying cefazolin in capillary whole blood collected via VAMS, plasma, and plasma ultrafiltrate, showing robust performance across matrices and successful application in a pediatric pilot cohort for therapeutic drug monitoring.