Analytical validation of capillary blood Krebs von den Lungen-6 measurement using a high- sensitivity chemiluminescent immunoassay in pediatric patients
Zhao et al.
The finding, in our words
Haematocrit correction of capillary blood samples reduced the mean bias against venous plasma from -48.32 to -3.47 U/mL and improved the Pearson correlation coefficient from 0.958 to 0.966 in 80 paired pediatric samples, with excellent repeatability (CV <3%). This demonstrates analytical feasibility of patient-centric microsampling for KL-6, though further validation is needed before clinical interchangeability.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
An IQ Consortium position paper from sponsor scientists positioning patient-centric sampling as the enabling technology for decentralised trials, and stating that a bridging study against conventional sampling “has quickly been established as a regulatory expectation”.
Maass et al., Clinical and Translational Science · 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 ↗
Fingerstick capillary sampling showed strong agreement with venous sampling for mycophenolic acid, tacrolimus and cyclosporine A, with acceptable bias and improved agreement for mycophenolic acid after haematocrit correction. This minimally invasive approach may reduce procedural burden and support outpatient or home based therapeutic drug monitoring in children.
Capillary finger-stick dried blood spots demonstrated strong analytical agreement with venous serum for prostate-specific antigen (R² = 0.987) and remained stable for 31 days across a wide temperature range. This less invasive microsampling approach enables at-home self-collection, supporting decentralised screening and tele-diagnostics for prostate cancer.
van Vugt et al., The journal of applied laboratory medicine (paywalled) · source ↗