New treatment for Alzheimer's? Scientists from the University Medical Center Göttingen have developed a novel vaccine that may not cure Alzheimer's but could stop it.
(07.11.2010) Researchers have succeeded for the first time in developing a vaccine that is effective in mice. The research results could raise new hopes for effective therapy for around 35 million people worldwide. As the researchers emphasize, the results could help develop a vaccine for humans in a few years. Although Alzheimer's cannot be cured by this, it can at least be stopped. However, doctors warn against falling into “euphoria” despite the positive results. Too often, patients' expectations and hopes for Alzheimer's researchers have been disappointed in the past ten years.
Alzheimer's is an organic clinical picture
Alzheimer's disease is an organic disease in the human brain. Alzheimer's is characterized by the fact that nerve cells and nerve contact cells die slowly but progressively. In the brain of Alzheimer's patients, physicians determine typical protein deposits for the disease in the diagnostic procedure. These are known as “amyloid plaques” in the professional world. So far, however, it is still unclear whether these plaques are triggers or just a typical symptom. There is still no agreement among scientists on this question. The disease was first discovered and researched by the neurologist Dr. Alois Alzheimer. He had scientifically examined and described the disease for the first time in 1906. The clinical picture was named after him.
Symptoms of the disease
Visible symptoms of Alzheimer's include memory and orientation disorders as well as a progressive decrease in the ability to think. Complex classifications and thinking processes are becoming increasingly difficult for the patient. Everyday tasks are becoming increasingly unsolvable for those affected, and in the end station the patients become a regular case of care. As people with Alzheimer's are not a homogeneous group, the requirements for medical care, nursing and care are often very different. Because previous skills and deficits also play an important role in the course of the disease. Alzheimer's doesn't just affect older patients. The first occurrence of the disease was already observed in 50 year olds.
Actual development of Alzheimer's is still unsolved
Since it is still unclear how Alzheimer's actually develops, there are also different research approaches. The most common assumption is that protein deposits form so-called plaques in the brain, which cause the destruction of nerve cells and synapses to increase. But researchers at the University of Göttingen have long doubted that these deposits are actually responsible for this. Rather, a special molecular structure in the brain could be responsible for the outbreak of Alzheimer's. The researcher and neurologist Prof. Dr. Thomas Bayer from the Clinical Department of Psychiatry and Psychotherapy at the University Medical Center Göttingen has already predicted from previous studies that plaques cannot be considered as triggers. Rather, they are a sign of Alzheimer's but not an origin. For this reason, the research work of the scientists went in a completely different direction.
Rather, it is assumed that special molecular structures in the brain are responsible for the development of Alzheimer's. This structure produces a protein called "Pyroglutamate Abeta". This protein causes the formation of so-called "oligomers", which clump together and attach themselves to the nerve cells and blood vessels. This negative process gradually damages the brain.
Göttingen Alzheimer's research approaches go in a different direction
The main focus of the researchers was to investigate the formation of so-called "oligomers" in more detail. Attempts to dissolve protein deposits have so far failed. Older studies had shown time and time again that destruction of the plaques had serious consequences. Neurologist Prof. Bayer explained this by saying that these protein deposits appear to be a kind of landfill for toxic proteins. For this reason, these deposits should also remain untouched in order to protect the brain from even greater damage. The amount of protein deposits can also give no indication of the extent to which Alzheimer's disease has progressed. Study results would have shown that the amount is not critical to how advanced cognitive loss is. Subjects who had a high concentration of protein deposits were nevertheless able to solve comparatively complex tasks. Others showed severe restrictions, although the number of plaques was rather small.
Stop the formation of toxic protein deposits with a passive vaccination
To pursue a different strand of research, the researchers have focused on preventing the formation of new toxicological protein deposits. The Göttingen scientists developed antibodies to eliminate the named “oligomers”. In an experimental set-up, rodents were given the appropriate injection of antibodies. "These antibodies are the first in the world to recognize a soluble, particularly toxic Abeta variant. Unlike the previous antibodies that were used for immunizations, they do not bind to plaques," said Prof. Bayer.
The dangerous “oligomers” could be stopped by the injection. Although vaccination in mice did not cure Alzheimer's, progression was stopped. The study leader Bayer commented on the results: "With this form of passive vaccination, we probably cannot achieve a cure, but our research results show that antibodies apparently stop the progression of Alzheimer's disease". According to information, it should already be possible in two years to carry out initial studies in humans. Because the results of the study could also be transferred to humans, according to the researchers in the medical science magazine "Journal of Biological Chemistry".
Cautious hopes despite good results
It will certainly take a few more years before an effective vaccine can actually be developed. It has also not yet been clarified whether the results lead in the right direction. For this reason, the director of the Clinic for Psychiatry and Psychotherapy at Charite Berlin warns of a veritable euphoria in the media. Because numerous other study results would have given the relatives and affected people courage again and again, but ultimately they were always disappointed. "After all the disappointments that not only we doctors have had to deal with, but also those affected in the past ten years, you have to be cautious now." so Dr. Isabella Heuser. However, the research approaches are an interesting push, even if there is still no hope of a cure. Prevention is still the best option. Regular exercise and a healthy diet can be proven to reduce the risk of Alzheimer's. (sb)
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