Alzheimer’s Disease: 8th most common cause of death

International experts gather in UCD this week (14-16 March 2005)* to discuss medical research into neurodegenerative diseases including the eighth most common cause of death in the developed world ¡V Alzheimer¡¦s Disease.

Alzheimer¡¦s Disease is a degenerative brain disorder that primarily affects older people. It may begin with simple forgetfulness but more advanced symptoms include confusion, language disturbances, personality and behaviour changes and impaired judgment. The disease duration can span from two to twenty years and the economic cost to families and society is enormous. US estimates put the cost of the disease there at $80 -100 billion per annum.

Dr Dominic Walsh from UCD¡¦s Conway Institute and a leading expert in Alzheimer¡¦s, has warned that, with its aging population, Ireland is sitting on a geriatric medical timebomb if the Government does not actively set the treatment of neurodegenerative diseases as a coherent research priority. ¡§The investment by Science Foundation Ireland (SFI) has been monumental in providing a base for world class scientific research in Ireland. However, we need to focus efforts across the Irish universities into areas where we can create a critical mass of research to make breakthroughs that will impact directly on Irish society.¡¨ He said.

Taking statistics from the US, the reality is that up to 50% of the population over 85 years of age suffer from Alzheimer¡¦s Diseases. Current estimates suggest that over 35,000 people in Ireland suffer with Alzheimer¡¦s disease and a further 30,000 have other lesser-known dementias. The single largest risk factor for developing Alzheimer¡¦s is age. Consequently, as life-expectancy increases so too will the incidence of dementia.

Dr Walsh is among 250 delegates from across the world working on different aspects of neurodegenerative diseases. Dr Walsh¡¦s work concentrates on the processes leading to plaque formation and the toxic events that result from it. He led the group that first identified toxic non-plaque forms of the amyloid protein and more recently has shown that these species can disrupt normal nerve cell activity and the ability to form and retrieve memory.

Alzheimer¡¦s is characterised by two pathological hallmarks; amyloid plaques and neurofibrillary tangles. Amyloid plaques are composed of a protein, the amyloid beta-protein (A£]) that is normally produced in every tissue of the body. A£] is a fragment of a protein that is snipped from another protein called the amyloid precursor protein (APP). In a healthy brain, A£] would be broken down and eliminated but in Alzheimer’s disease, it accumulates to form insoluble amyloid plaques. Neurofibrillary tangles, which are believed to develop as a consequence of the build up of toxic A£] ƒzconsist of insoluble twisted fibres that are found inside brain cells. They primarily consist of a protein called tau, which is involved in neuronal transport delivering nutrients and other important substances from one part of the nerve cell to another. In Alzheimer’s disease, however, the tau protein is malformed and normal transport is blocked

Scientists believe that if they can reduce the accumulation of toxic A£], they will be able to ultimately cure the disease.

Among the internationally renowned experts speaking at the conference are:

Professor Dennis Selkoe, Harvard Medical School, is widely regarded as the leading expert in the field of Alzheimer research and has made a number of major breakthroughs in the area.

Professor John Hardy, director of the Laboratory of Neurogenetics, National Institutes of Health who discovered the first mutation (in APP) associated with inherited forms of Alzheimer¡¦s disease.

Dr Martin Citron, head of neurodegenerative research, Amgen, who was nominated by Time magazine in the nineties as one of the ¡¥most intriguing people of decade¡¦. Dr Citron progressed research by identifying one of the enzymes required for A£] ƒngeneration.

Medical research generally takes years to progress from a laboratory setting to clinical trials and eventually into general use for disease sufferers. Currently Elan and Wyeth are conducting Phase I trials for a passive immunisation treatment that involves injecting anti-A£] ƒnantibodies into the bloodstream of a small number of selected patients. Potentially successful therapeutics if approved, will progress to Phase II with a wider group of carefully monitored patients and then a larger Phase III trial involving longer-term treatment and a large number of volunteers. Before a drug can hit the market researchers must satisfy the requirements of drug regulatory authorities (the FDA in the US and the IMB in Ireland) with respect to the safety and effectiveness of the treatment.

*The Molecular Mechanisms of Neurodegeneration conference is a joint Biochemical Society/Neuroscience Ireland focused meeting under the chairmanship of Dr Dominic Walsh.

The full programme is accessible on: http://www.ucd.ie/conway/event_9.html