Epidemiological studies have suggested that either rheumatoid arthritis itself – or the anti-inflammatory drugs used to control it – are associated with a reduced risk of developing Alzheimer’s disease. Recent clinical trials with non-steroidal anti-inflammatory drugs (NSAIDs) have failed to show a benefit in patients with Alzheimer’s disease and researchers at the University of South Florida have now shown that it may be the disease itself that affords protection.
In a mouse model of Alzheimer’s disease, one of the cytokines that is elevated in patients with rheumatoid arthritis, granulocyte-macrophage colony-stimulating factor (GM-CSF), was shown to improve working memory and learning and to lead to an apparent increase in neural cell connections in the animals’ brains. GM-CSF also led to an accumulation of microglia in the brains of treated animals which was associated with a greater than 50% reduction in β-amyloid peptides. Recombinant human GM-CSF is currently approved to stimulate the production of white blood cells in some cancer patients and the new study, which is published in the Journal of Alzheimer’s Disease, suggests that GM-CSF could also be of benefit to Alzheimer’s patients.
The USF Health Byrd Alzheimer’s Institute plans to begin a pilot clinical trial later this year to investigate recombinant human GM-CSF in patients with mild or moderate Alzheimer’s disease.