2022 · Clinical and translational science · open access
Evaluation of CYP1A2 activity: Relationship between the endogenous urinary 6-hydroxymelatonin to melatonin ratio and paraxanthine to caffeine ratio in dried blood spots
Magliocco et al.
The finding, in our words
A strong linear relationship was found between the urinary 6-hydroxymelatonin/melatonin ratio and the paraxanthine/caffeine ratio measured in dried blood spots, indicating that the urinary ratio can serve as a noninvasive surrogate marker for CYP1A2 activity. This enables assessment of drug metabolism capacity using self-collected urine samples, avoiding the need for blood sampling.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Blood-based matrices such as serum and dried blood spots offer direct access to circulating analytes, overcoming key detection limitations of traditional urine testing for agents like erythropoiesis-stimulating drugs and peptide hormones. Capillary microsampling technologies provide simplified collection workflows that support the expansion of multi-matrix anti-doping and biological passport programmes.
This systematic review of 67 studies involving 34,739 kidney disease patients found dried blood microsampling was mainly used for immunosuppressant therapeutic drug monitoring and kidney function assessment. The approach offered cost savings, was preferred by patients for home self-collection, and provides a patient-centric opportunity to upscale longitudinal sampling and reduce participation bias in decentralised kidney disease research.
Lamond et al., Journal of clinical laboratory analysis · source ↗
The review evaluates microsampling techniques including dried matrix spots, volumetric absorptive microsampling and capillary microsampling for SARS-CoV-2 bioanalytical applications, outlining their respective advantages and disadvantages to guide researchers and clinicians in pandemic-related diagnostics.
Protti et al., Journal of pharmaceutical and biomedical analysis · source ↗
Capillary dried blood spots, after haematocrit-dependent conversion, showed good agreement with plasma for 25-hydroxyvitamin D quantification, with 90 per cent of results within 20 per cent of plasma and substantial to almost perfect agreement in status classification, supporting reliable home self-collection for large-scale vitamin D monitoring.
Heughebaert et al., Clinical chemistry and laboratory medicine (paywalled) · source ↗
This study validated a dried blood spot method for tacrolimus monitoring and demonstrated agreement with venous whole blood measurements in kidney transplant recipients. It also found that dried blood spot analysis of the biomarker CXCL-10 was elevated in patients experiencing rejection or infection, supporting its use for decentralised monitoring.