2024 · Clinical chemistry and laboratory medicine · paywalled
Remote HbA<sub>1c</sub> testing via microsampling: fit for purpose?
Verougstraete et al.
The finding, in our words
This review of remote HbA1c testing via capillary blood microsampling finds that both dried and liquid formats can produce results comparable to venous sampling when collection, stability and extraction are properly validated. It matters because self-collected microsamples could enable decentralised diabetes monitoring and telemedicine, but heterogeneity in study designs and methods must be resolved before reliable implementation.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Dried VAMS and DBS samples collected at home and analysed after a median of three days showed poor agreement with standard venous or capillary blood for HbA1c monitoring. In contrast, wet VAMS samples analysed immediately demonstrated excellent agreement, indicating that sample drying and delayed analysis compromise reliability for decentralised HbA1c measurement.
Volumetric microsampling can enable patient-centred therapeutic drug monitoring with high patient preference and acceptable method validation for many drugs, but conversion from capillary to plasma and agreement with venous sampling varies by analyte and requires careful validation.
In a cohort of 62 participants evaluating home self-collection with the TassoPlus device, 38 returned samples, with 29% excluded due to insufficient plasma volume below 200 ΔL. Although viral load measurements in adequate samples correlated well with conventional testing (r = 0.800), the high failure rate and missed detection in low-volume viremic samples indicate that further technical refinements are necessary before clinical adoption.
Home DBS sampling gave testosterone results that agreed well with venous blood in men on intramuscular testosterone undecanoate, but showed falsely high values in those using topical gel, likely from skin contamination. Patients preferred home collection for its convenience, suggesting DBS is viable for decentralised monitoring of injectable testosterone if patients are taught proper technique.
This study established conversion methods for estimating plasma concentrations from whole blood VAMS samples for seven out of ten oral anticancer drugs, finding good agreement between capillary and venous samples. Patients reported a positive experience with home sampling using this microsampling technique.