This study investigated plasma proteins in drug-naive first-episode psychosis (FEP) patients and healthy controls using a multiplex proximity extension assay. Analysis of 92 immune markers in 60 FEP patients and 50 controls, using multivariate statistical methods and protein pathway analyses, revealed 11 significantly different proteins. Increases in pro-inflammatory proteins like interleukin-6, oncostatin-M, transforming growth factor-alpha, and extracellular newly identified RAGE-binding protein (EN-RAGE) were observed in FEP patients. Elevated EN-RAGE, derived from neutrophils, may play a crucial role in the early stages of acute psychosis by stimulating cytokines and immune responses, potentially targeting the brain vasculature.

Laura Korhonen, Elisabeth R. Paul, Karin Wählén, Liina Haring, Eero Vasar, Antti Vaheri, Dan Lindholm