Dried blood spot samples as a diagnostic and prognostic tool for neonatal sepsis in preterm infants

Neonatal sepsis is associated with short and long-term complications and high mortality if untreated (1). The incidence of neonatal sepsis has been decreasing in extremely low birth weight and preterm infants, yet the incidence of neonatal sepsis associated mortality and length of hospital stay has failed to decrease (2). Rapid and accurate diagnosis based on laboratory and clinical findings remains a challenge despite extensive investigation of the molecular mechanisms behind neonatal sepsis (1). Our novel study investigates the proteome, metabolome and liquid biomarkers such as PTMs and EVs for prognostic markers of late onset sepsis using dried blood spot (DBS), comparing whole blood with plasma in a cross-species comparison. Methods DBS and plasma samples from preterm piglet experimental sepsis models and human preterm infants were used for identification of potential diagnostic and prognostic markers. Proteomics and metabolomics investigations were performed on 3 mm punched DBS samples lysed in SDS and analyzed using high-end LC-MS/MS using DIA and PASEF followed by datamining. Results and Conclusion Recently, it has been shown that stability of proteins and metabolites in DBS samples persists and may serve as tool for diagnosis and clinical prognostics (3). Our optimized multiple-extraction strategy allowed insight into sepsis markers (>1300 proteins) and differences in whole blood vs. plasma based diagnostics.