MELISSA BLOCK, HOST:
Thousands of researchers into Alzheimer's disease have gathered here in Washington this week for the annual Alzheimer's Association International Conference. They're presenting research on risk factors, diagnosis and treatment. More than 5 million Americans are living with the disease. That numbers says the Association is expected to nearly triple by 2050. Dr. David Knopman is a neurologist with the Mayo Clinic's Alzheimer's Disease Research Center, and he's taken some time away from the conference to join me here in the studio. Thanks for coming in.
DAVID KNOPMAN: Thanks for asking.
BLOCK: And what have you heard this week, Dr. Knopman, that seems especially promising when you think about early diagnosis of Alzheimer's disease - any new testing methods that would screen for the disease more easily?
KNOPMAN: Well, I think I need to preface this by saying that prior to five or 10 years ago, a diagnosis of Alzheimer's disease dementia was made entirely on a very low-tech basis by taking history from the patient and family and doing a neurologic exam. Over the last 10 years, the field has now become able to look into the brain, as it were, with imaging and spinal fluid techniques that happen to be expensive and invasive at the present time but that at least give us a definitive answer, especially for research, about whether the person harbors the biology of Alzheimer's disease or not.
If we're going to scale this up for its use in primary care, we can't do it by requiring $5,000-per-person scans. We have to develop something that can be done on a more noninvasive and less expensive way. And some of the studies that were presented here that include blood tests using very sophisticated biochemical strategies or saliva tests that actually use the same underlying high-tech approaches hopefully will eventually hit pay dirt as well and lead to an inexpensive way to detect the pathology of Alzheimer's disease, even when people don't have symptoms.
BLOCK: The trick there, though, is that even if you do have early detection, if there's not an effective treatment for Alzheimer's disease, what's in it for a patient to know they are developing Alzheimer's if there is no way to treat it or cure it?
KNOPMAN: Well, Melissa, that's exactly correct. And at the moment, we discourage people from having these amyloid PET scans if they're normal because there's no point in knowing that you're at risk if there's not an effective treatment, absolutely.
BLOCK: Well, what about that? What about new treatment options or experiments that are being done that you've heard about this week? Is there anything that's giving you some hope?
KNOPMAN: Right. There were several presentations today of drugs that showed promising early results. They weren't definitive. They're not going to lead to a therapy being approved next week or even next year. But clearly, progress is being made.
BLOCK: I think some of these drugs, at the same time, have shown results that were less hopeful than had been predicted or the outcomes had not been as strong as people had hoped.
KNOPMAN: Yes. That's correct. One of the drugs that was presented today, in fact, in its major reporting of results, was negative. In other words, there were no significant results. But we learned from that trial, and the company who's doing it learned from that trial and redesigned their future studies, which are actually ongoing, based on what they learned previously. So we're learning even when we have negative studies.
BLOCK: That's the silver lining.
KNOPMAN: Yes (laughter). We can always find a silver lining. But truly, you don't learn unless you make mistakes, and we've made our share.
BLOCK: If you think about the course of Alzheimer's research over the time that you've been involved with this science, where are we on that curve? Are advances being made at a greater rate than before? Is it a fairly steady slope?
KNOPMAN: Oh, no. This is, I feel, exponential. I've been involved since the early 1980s, and at that time, people didn't even know what Alzheimer's was. I think in the last 10 years, there has been a real quantum leap in sophistication that is truly staggering in its intensity, also its cost, but also in the kind of answers it can deliver.
BLOCK: I'm interested to hear you sounding so optimistic, Dr. Knopman. As long as you've been doing this and seeing the frustration and the terrible toll that Alzheimer's takes on patients and on families, I do wonder how you keep from getting terribly depressed in what you do.
KNOPMAN: (Laughter). Well, I have to tell patients and families every day that we don't have a therapy that's available yet. But I take heart in the kind of progress we're making in understanding the biology of the disease. And I believe - I guess I have to believe - that if I'm going to continue - and I am - that this is going to lead to an avenue of therapy that's going to be successful. When I think of how far we've come in our knowledge of the disease, I am excited. I wish we had a drug that was more beneficial, but I have to be optimistic while, at the same time, being cautious. We're not there yet, and I don't know when we're going to succeed. I just think that eventually we will.
BLOCK: Dr. Knopman, thanks so much for coming in. It's good to talk to you.
KNOPMAN: Thank you, Melissa, for having me.
BLOCK: David Knopman is a neurologist with the Alzheimer's Disease Research Center at the Mayo Clinic. He's also vice chair of the Alzheimer's Association's Medical and Scientific Advisory Council. Transcript provided by NPR, Copyright NPR.