Objectives: Blood-based biomarker profiling holds great promise for the early detection of neurodegenerative diseases. However, standard-ization of sample collection and storage conditions is critical for reliable and accurate testing. Dried blood spots (DBS) and dried plasma spots (DPS) provide alternative collection methods for longitudinal, population-wide studies especially in remote areas with a lack of infrastructure and warrant further evaluation for compatibility with highly multiplexed proteomic platforms for profiling key markers of disease pathogenesis including pTaus, amyloid betas, and inflammatory cytokines.

Methods: Multiple commercially available dried blood spots and dried plasma spots collection devices were evaluated in comparison with matched whole blood and plasma from healthy and diseased subjects with the NULISAseq 120-plex CNS Disease Panel on the ARGO™ HT platform. Different extraction conditions and sample input volumes were tested to determine optimal conditions for detection of key neurodegenerative and inflammatory targets at high sensitivity. Pearson correlation analysis was performed to determine the concordance between matched whole blood and DBS as well as plasma and DPS.

Results: Our preliminary results show high detectability in DBS (>90%) and DPS (>85%), comparable to overall detectability in paired whole blood and plasma samples. Additionally, key CNS targets such as NFL, GFAP, pTaus (pTau-181, pTau-217 and pTau-231) showed close to 100% detectability. Overall, relative protein quantification in DBS and DPS demonstrate high correlations with matched blood and plasma respectively (r>0.75). We have developed an optimized protocol for extraction of proteins from DBS and DPS followed by evaluation with the NULISAseq technology. Our data suggests that most targets of interest are compatible with this type of collection method and DBS/DPS can be a promising substitute for blood-based profiling with added benefits of ease of collection, storage, transportation and analysis.