In order to investigate inflammation and apoptosis in Creutzfeldt-Jakob disease (CJD) patients, we analyzed astrocytes, microglia and apoptotic neurons in brain and IL-1beta in cerebrospinal fluid (CSF). Our results showed increased numbers of astrocytes in CJD and increased numbers of microglia and apoptotic neurons both in CJD and Alzheimer's disease (AD) as compared to controls. All these markers correlated (P < 0.001) with the severity of the neuropathological lesions. An increased IL-1beta concentration was found in AD and CJD CSF that correlated with the number of microglia and which did not change in the disease course of CJD.In conclusion, apoptotic neurons in CJD correlates to the neuropathological lesions and are probably related to the presence of inflammatory cells and cytokines which are present during the whole CJD disease process.