Hope Meets Hype

By Christine Gorman

This is the hardest kind of story for me to write. It's about a real advance in basic research on Alzheimer's. I know all too well that there are millions of people desperate for news of a treatment or a cure for this terrible disease. I also know that it can take five years or more for basic research--which is to say, experiments performed in test tubes or on laboratory animals--to be turned into safe and effective drugs. And that's only if there are no major setbacks or surprises. More often than not, these big advances in basic research don't go anywhere at all. So when I read a report in the journal Nature last week about a possible breakthrough in Alzheimer's research, I found myself once again negotiating a tightrope between real promise and false hope. One of the hallmarks of Alzheimer's is the formation of sticky clumps of protein, called amyloid plaques, in the brains of affected patients. Scientists from Elan Pharmaceuticals, a biotech company headquartered in Ireland, reported they had produced a vaccine that could prevent plaques from forming and dissolve existing ones in the brains of mice. They speculated that a similar approach might be used to treat people.

Some of my colleagues jumped on the news. In his lead story on ABC World News Tonight, Peter Jennings called the report "the very best news [about Alzheimer's] there has been in many years, perhaps ever." The Wall Street Journal ran a more skeptical, enterprising piece, but it too gave top billing to the story. Normally cautious neuroscientists were genuinely enthusiastic, but somehow their sound bites came across as overly optimistic.

What got lost in the enthusiasm was a sense of how difficult it is to make the leap from mice to men--especially in this case. For starters, mice don't get Alzheimer's disease. The rodents in these experiments were genetically engineered to produce amyloid plaques, but they don't exhibit any of the other telltale signs of Alzheimer's. Indeed, scientists aren't sure whether plaques are a cause or an effect of the disease. A vaccine that removes plaques in mice could still fail to treat the underlying disease in people.

Then there's the possibility that a vaccine will do more harm than good. Every time you stimulate the immune system, you run the risk of triggering an inflammatory reaction, marked by fever, swelling and tissue destruction. In fact, many researchers believe the real destructive power of Alzheimer's comes not from the plaques but from the immune system's overreaction to them. The vaccine might also cross-react with other proteins, triggering an autoimmune reaction in which the body attacked its own brain cells.

All this remains to be discovered. The most important thing to take away from this research news is that it's a "proof of concept," as scientists call it. Before now, they weren't sure they could dissolve amyloid plaques outside a test tube. Now they know they can. Even if vaccination turns out not to be the best route, researchers have a direction in which to concentrate their efforts. And sometimes in science, that's all you need.

For more on Alzheimer's disease, visit our website at time.com/personal Questions? E-mail Christine at [email protected]