Investigating the relationship between inflammatory cytokines and PTSD: A comparative analysis

Background
Post-traumatic stress disorder (PTSD) is a complex psychiatric disorder that emerges following exposure to traumatic events and is increasingly linked to inflammatory dysregulation. Identifying reliable biomarkers is essential for improving diagnosis of PTSD.
Methods
This study included 38 patients with PTSD and 42 age- and sex-matched controls. Serum inflammatory proteins were profiled using Olink proteomics. Differentially expressed proteins were validated by ELISA, and their associations with PTSD symptoms and diagnostic performance were assessed using correlation and ROC analyses.
Results
The serum levels of inflammatory proteins CXCL9, ST1A1, and Flt3L were significantly elevated in PTSD patients compared to normal controls (p < 0.05). ELISA validation confirmed the elevated expression patterns of these inflammatory proteins. Among them, Flt3L showed a significant positive correlation with PCL-5 scores (r = 0.374, p < 0.05), indicating a link between its expression and symptom severity. ROC analysis revealed that the combination of CXCL9, ST1A1, and Flt3L yielded the highest predictive value for PTSD (AUC=0.746, p < 0.05), followed by the combinations of CXCL9 + Flt3L (AUC = 0.744) and Flt3L + ST1A1 (AUC = 0.727). Individually, the AUC values for CXCL9, Flt3L, ST1A1, and CXCL9 + ST1A1 were 0.637, 0.718, 0.632, and 0.662, respectively (all p < 0.05).LimitationThe study was limited by its relatively small sample size and the restricted panel of inflammatory markers.ConclusionCXCL9, ST1A1, and Flt3L show potential as peripheral biomarkers for PTSD, with Flt3L particularly associated with symptom severity. These findings offer new insights into the role of inflammation in PTSD and may contribute to more objective diagnostic tools and individualized treatment strategies.