Alzheimer's Club

A medical researcher who grew up in Manchester is trying to get other researchers interested in what he calls a "truly revolutionary notion," that the bacterium that causes Lyme disease may also be at the root of many cases of Alzheimer's disease.

A scientific journal called "Medical Hypotheses" this week published on the Internet the second in a series of papers in which the researcher, Dr. Alan B. MacDonald, sets forth his ideas on the subject.

"Medical Hypotheses" says in a description of its aims and scope that it will publish "radical ideas, so long as they are coherent and clearly expressed."

MacDonald, who works as a pathologist at a Long Island hospital, makes clear that the title of the journal aptly describes his idea: It is a hypothesis, meaning an unproven theory used to design further experiments to confirm or refute it.

But if MacDonald's idea should prove out, it would open new possibilities for prevention and treatment of Alzheimer's disease, in that bacterial infections can be treated with antibiotics.

Lyme disease is caused by a spirochete, a corkscrew-shaped bacterium, known as Borrelia burgdorferi. It was first identified in the United States as a result of an outbreak of arthritis-like symptoms in 1975 in Lyme, Old Lyme, and East Haddam, Conn.

Lyme disease is also known to have neurological effects in some cases.
Alzheimer's is a common neurological disease in which the mental abilities of patients steadily deteriorate, leading ultimately to their deaths. It primarily afflicts the elderly but can strike younger people as well.

MacDonald has been interested in the possibility of a connection between the Lyme spirochete and major neurological diseases, including Alzheimer's, for more than two decades. But, while working as a pathologist, a doctor who specializes in diagnosing diseases in tissues removed from the body or studied during autopsies, he hasn't always been in a position to do research on the subject.

MacDonald's new paper is based on research showing that the spirochete that causes Lyme disease can take on the rounded form of a cyst under adverse conditions, such as starvation, an acidic environment, or attack by antibiotics.

"Anything that needs to survive adversity will round up and form a cyst," he said in a telephone interview from Long Island, where he works at St. Catherine of Siena Medical Center in Smithtown, N.Y.

He suggests the possibility that these rounded forms of the spirochete might be the "root cause" of the rounded structures called plaques found in the brains of Alzheimer's patients. He says there are structural and other similarities between Lyme cysts and Alzheimer's plaques.

Moreover, MacDonald says, he has found evidence in seven of 10 known Alzheimer's brains of "transfection" with DNA from the Lyme spirochete. Transfection is the incorporation of a piece of DNA from an alien species into human DNA.

He has used this information to design a DNA probe, which he then used on the brain of a deceased Alzheimer's patient who was known to have had Lyme disease. The DNA probes showed a pattern similar to the distribution, size, and shape of Alzheimer's plaques, according to his article.

MacDonald says in the article that some have suggested that the overlap between evidence of Lyme infection and evidence of Alzheimer's may be a coincidence, in that both diseases are relatively common.

But he suggests that that argument may be refuted if it can be shown that Lyme DNA regularly appears at the site of the tissue injuries that define Alzheimer's disease.

"DNA of the alleged perpetrator at the scene of the crime constitutes 'molecular proof'" that the Lyme spirochete causes Alzheimer's disease, he writes.

Dr. Christopher H. van Dyck, the director of the Alzheimer's disease research unit at the Yale University
School of Medicine, said Friday that MacDonald's hypothesis "sounds speculative but interesting. It probably is worthy of additional research."

He said there is known to be more than one cause of Alzheimer's disease.

Van Dyck, who is chairman of the medical scientific advisory committee of the Alzheimer's Association's Connecticut chapter, suggested that one focus of additional research might whether Alzheimer's disease is more common in areas where Lyme disease is found.

"There's no way it can be the cause of all Alzheimer's disease," van Dyck said. "There are genetic mutations that are known to cause Alzheimer's disease."

Source: Alex Wood. A truly revolutionary notion:'Medical researcher with ties to Manchester studies possibility of Lyme disease-Alzheimer's link. Journal Inquirer(5 May 2006) [FullText]