Glial fibrillary acidic protein and protein S-100B: Different concentration pattern of glial proteins in cerebrospinal fluid of patients with Alzheimer' s disease and Creutzfeldt-Jakob disease

Glial fibrillary acidic protein (GFAP) and protein S-100B are accepted indicators for astrogliosis in neuropathology. As GFAP and S-100B are expressed in different cell populations, variable CSF concentrations of these proteins might reflect disease-specific pathological profiles. Therefore, we investigated CSF of patients with Alzheimer's disease (AD), patients with Creutzfeldt-Jakob disease (CJD) and non-demented control patients (CON). Measurement of GFAP and S-100B in CSF was performed with commercially available ELISA. In AD, there are significantly higher levels of GFAP concentrations, compared to CON (p = 0.001) and CJD patients (p = 0.009). Whereas S-100B is much higher in CJD, compared to AD (p = 0.001) and CON (p = 0.001). GFAP and S-100B represent astroglial markers. Here, we observed different levels of both proteins in CSF of AD and CJD patients, which might point to a distinct pathophysiological involvement in these diseases. Apart from pathophysiological aspects, especially GFAP might serve as additional diagnostic tool for AD, due to the fact that this protein does not correlate to established markers like tau and amyloid ß, so that the analysis of GFAP may be useful for further differential diagnostic approaches in neurodegenerative diseases.