Mass Spectrometry-Based Quantification of Proteins and Post-Translational Modifications in Dried Blood: Longitudinal Sampling of Patients With Sepsis in Tanzania.

Summary

This proof-of-concept study establishes an integrated mass-spectrometry workflow to quantify proteome, N-glycoproteome, and phosphoproteome from dried blood in sepsis, enabling longitudinal phenotyping without plasma separation. It captures acute-phase and neutrophil-driven inflammatory signatures that partially resolve by 1 month and correlates with clinical markers; datasets are publicly available.

Key Findings

• Integrated quantification of ~2000 proteins and ~8000 PTMs (N-glycopeptides and phosphopeptides) from dried blood was achieved across 96 samples with ~1.5 h LC-MS/MS per sample.
• Longitudinal profiles showed acute-phase response and neutrophil inflammation signatures at presentation that partially resolved by 28–42 days.
• Multiple analytes correlated with CRP, WBC counts, and Universal Vital Assessment severity scores.
• The approach avoided plasma/cell separation, reducing pre-analytical variability, and datasets were deposited (ProteomeXchange PXD060377).

Clinical Implications

Dried blood microsampling coupled with MS could support decentralized sepsis diagnostics and trajectory monitoring, enabling serial sampling and transport without cold chain; targeted panels derived from these data may translate into practical assays.

Limitations

• Single-country, modest sample size (38 patients) limits generalizability and power for clinical outcome associations.
• Lack of direct head-to-head comparison with matched plasma-based assays; clinical endpoints (e.g., mortality) were not analyzed.

Future Directions

Validate candidate protein/PTM panels in larger, multi-center cohorts; benchmark against plasma/serum assays; develop targeted MS or immunoassays for clinical deployment.