Capillary blood sampling in neurodegenerative diseases - the future for screening and monitoring brain health?

Abstract

Introduction: Blood-based biomarkers are becoming increasingly utilized in the neurodegenerative research field for indicating patient disease status. With increasing emphasis on large-scale prevention trials, developing cost-effective and accessible means of sampling for these biomarkers is imperative. Micro-sampling, in the form of dried blood spots (DBS), dried plasma spots (DPS), and upper-arm devices (UAD), could be a solution.

Areas covered: Herein, the authors review recent studies that have explored the validity of DBS, DPS and UAD for detecting neurodegenerative blood biomarkers. Overall, DPS and UAD present most potential, with good to excellent correlation of pTau-217, NfL, and GFAP to concentrations in gold-standard venous plasma or CSF. However, while these results show exciting promise for implementing micro-samples, there are limitations regarding sample variability, storage, and handling.

Expert opinion: There is still significant work needed to validate DPS and UAD sampling: current research is fragmented and with varying cohorts, there is no standardized methodology for micro-sample extraction and analysis, and lack of knowledge of the influence of pre-analytical handling means that wide implementation for trials is currently restricted. But current efforts from research groups and industry suggest that capillary micro-samples have great potential for detecting a broad range of biomarkers.