Molecular subgroups of ALS patients with distinct survival outcomes identified through plasma proteomics

Amyotrophic Lateral Sclerosis (ALS) is a phenotypically diverse neurodegenerative disorder characterized by the degeneration of motor neurons, ultimately resulting in loss of motor function. Currently, patients are classified based on clinical factors which does not fully capture the heterogeneity. Using the Olink Explore HT, we pro-filed ~5400 plasma proteins in ALS patients (n = 235) from the ALSrisc Study at Karolinska Institutet, Sweden, and applied consensus clustering, which revealed three patient subgroups significantly differing in survival outcome. Weighted gene correlation network analysis (WGCNA) and gene ontology (GO) analysis identified protein modules related to biological functions including cellular stress response and Rho-GTPase activity for the shorter surviving patient group. Cell‑type enrichment analysis indicating a broad cellular origin of the circulating proteome, with contributions from nervous system cells, vascular cells, immune cells, and muscle cells. Our work highlights the potential of plasma proteomics for clinically meaningful patient stratification in ALS.