2023 · The journal of applied laboratory medicine · paywalled
Standard Venipuncture vs a Capillary Blood Collection Device for the Prospective Determination of Abnormal Liver Chemistry
Wickremsinhe et al.
The finding, in our words
The Tasso+ capillary blood collection device showed substantial to almost perfect concordance with standard venipuncture for measuring abnormal liver function tests including ALT, ALP, AST and total bilirubin, and patient feedback indicated a very favourable experience, supporting its use for more frequent and convenient testing outside the clinic.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
Capillary fingerstick sampling showed high correlation and agreement with venous sampling for serum AMH but with proportional bias, so it may improve access to testing yet should not be considered fully interchangeable without further validation.
Capillary blood collected with Tasso+ devices demonstrated strong agreement with venous blood for primary Athlete Biological Passport markers (haemoglobin, reticulocytes, OFF-score, ABPS) with correlations ≥0.9, though platelet count showed poor concordance. Despite 44 of 209 samples failing pre-analytical checks mainly due to coagulation, high athlete acceptance and minimal pain support capillary sampling as a less invasive, viable alternative for decentralised anti-doping controls.
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.