Serum growth differentiation factor-15, glial fibrillary acidic protein, and neurofilament light chain: Their link and role in Creutzfeldt-Jakob disease

Background: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive neurodegenerative disorder characterized by neuronal damage. Emerging biomarkers, such as serum neurofilament light chain (sNfL), glial fibrillary acidic protein (sGFAP), and growth differentiation factor-15 (sGDF-15), are currently being studied for their potential use in this disease. Objectives: This study analyzes the levels of sNfL, sGFAP, and sGDF-15, as well as their relationships, in patients with CJD compared to healthy controls (HC). Methods: A total of 19 CJD patients and 81 age- and sex-matched HCs were enrolled. Serum levels of sNfL and sGFAP were measured using ultrasensitive immunoassays, while sGDF-15 levels were assessed via ELISA. Statistical analyses included correlation analysis and analysis of covariance (ANCOVA) models. Results: CJD patients showed significantly higher serum levels of sNfL and sGFAP compared to HCs (p <0,001). sNfL levels were positively correlated with both sGFAP (Rho = 0,70; p < 0,001) and sGDF-15 (Rho = 0,60; p = 0,004). Interestingly, sGFAP levels were higher in female CJD patients compared to males (p = 0,001), while no significant difference in sNfL levels was observed between sexes. Conclusions: In conclusion, this study explores the potential of sNfL, sGDF-15, and sGFAP as biomarkers in CJD patients. The higher levels of sNfL and sGFAP in CJD patients compared to healthy controls, along with the observed sex differences in sGFAP, highlight the need for further research into the interaction between astroglia and neurons in CJD, with a focus on sex as a key variable.