Dried blood spot sample extraction for metabolomics and proteomics profiling for clinical trials: a descriptive exploratory study

Biomarker research relies on venous blood sampling, which demands trained professionals and proper sample handling, presenting challenges for both rural health care providers and large-scale studies. This study aims to investigate the use of dried blood spots (DBS) as a minimally invasive, patient-centric alternative for biomarker discovery in preparation of a decentralized type 2 diabetes (T2D) trial. To optimize and validate the method, DBS were collected from 2 and 14 healthy participants, respectively. Protein extraction was optimized, evaluated, and samples were analyzed by multi-spot antibody assays, two-dimensional gel electrophoresis, liquid chromatography coupled to tandem mass spectrometry, and nuclear magnetic resonance spectroscopy. The main findings revealed adequate extraction from filter paper, with detection of low abundant inflammatory cytokines. Additionally, proteins and metabolites previously implicated in T2D pathophysiology were detected. In conclusion, the findings in this study support DBS-based proteomics and metabolomics for the identification of novel biomarkers associated with human disease, which offers a scalable and accessible alternative to conventional blood sampling methods for clinical trial studies.