We very much appreciate the valuable comments by Iwasaki et al. We agree that elevated levels of the anti-inflammatory cytokines IL-4 and IL-10 in the CSF may reflect the neurodegenerative process in Creutzfeldt-Jakob disease. However, we do not know to date in which pathological pathway IL-4 and IL-10 are involved in Creutzfeldt-Jakob disease. This indeed is a subject of interest and should be investigated in further studies using animal disease models and human brain material. Here it would be important to clarify whether the release of IL-4 and IL-10 is directly associated with PrPSc accumulation and neuronal death or whether it reflects an immunological response mediated by immunological potent CNS cells, microglia, and astrocytes.
Stoeck K, Zerr I. Interleukin 4 and Interleukin 10 in Creutzfeldt-Jakob Disease—Reply. Arch Neurol. 2006;63(6):911. doi:10.1001/archneur.63.6.911-b