Creutzfeldt-Jakob disease in a patient treated by etanercept for rheumatoid arthritis (RA): just a coincidence?

We describe a patient in whom sporadic Creutzfeldt-Jakob disease (sCJD) occurred one year after the onset of etanercept therapy for rheumatoid arthritis (RA). This association could be a chance occurrence. However, TNF-alpha has been implicated in the pathogenesis of neurodegeneration in sCJD and etanercept might worsen the disease. Such an aggravation has been observed in multiple sclerosis, in which TNF-alpha is the key mediator of demyelination. It may be of interest studying the impact of treatment with TNF-alpha antagonists on prevalence and incidence of those neurodegenerative diseases involving TNF-alpha mediation, such as Alzheimer disease.