As growing evidence suggests there is a link between blood iron levels and the development of Alzheimer’s disease, new research investigating the effects of a drug that reduces available iron has raised concerns about its use as a treatment for the disease.

With agingIron deposits in different regions of the brain can impair normal cognitive functioning. Studies discovered that iron plays a role in the development of Alzheimer’s disease, with excessive iron levels contributing to beta-amyloid deposition and the formation of tangles in the brain that promote neurodegeneration.

For this reason, drugs that reduce iron overload by binding to iron, a process called chelation, have received much attention as potential treatments for Alzheimer’s disease. However, new research examining the effects of a particular iron chelating drug on the progression of Alzheimer’s disease has sparked concern.

The study was a collaboration between Australian institutions including the Florey Institute of Neuroscience and Mental Health (The Florey), University of Melbourne, University of New South Wales (UNSW), Monash University, Curtin University, the Queensland Brain Institute, the Commonwealth Scientific and Industrial Research Organization (CSIRO) and Newcastle University.

Researchers studied the drug deferiprone, an iron chelator usually used to remove excess iron in people with certain blood disorders (thalassemia, sickle cell anemia) who have too much iron in their body due to repeated blood transfusions. The 12-month clinical trial was conducted in 81 patients aged over 54 with mild cognitive impairment or early-onset Alzheimer’s disease and confirmed amyloid deposits. Participants were randomized to receive either 15 mg/kg oral deferiprone twice daily or placebo. The primary outcome was improvements in cognitive functioning – memory, executive function and attention – which researchers assessed at baseline, six and 12 months. Secondary outcomes included a change in brain iron levels.

MRI scans showed that, compared to patients in the placebo group, those treated with deferiprone had reduced iron levels in the hippocampus, a region of the brain heavily involved in memory. However, even though the drug reduced iron levels in the brain, patients given the drug showed accelerated overall cognitive decline, primarily due to worse performance on tests of executive functions. Executive functioning is the term given to the higher-level mental processes that allow us to make plans, focus attention, remember, and juggle multiple tasks.

The researchers say their trial results suggest that reducing iron levels using deferiprone makes people with Alzheimer’s disease worse.

The study was published in the journal JAMA Neurology.

Source: Scimex