Chicago Tribune: New stem cell therapy may be fatal

[Guest guest]

New stem cell therapy may be fatal

By Gorner

Tribune science reporter

June 4, 2002

Three years ago, Sears was a carefree college student whose hands

mysteriously started to shake when he tried to use his computer keyboard.

The tremors were sporadic at first, but grew increasingly severe. He tried

to ignore what was happening to his hands, but he soon started having

trouble with his balance. Before long, he couldn't even climb stairs.

He was diagnosed with multiple sclerosis (MS), a chronic, neurological

disorder that affects 350,000 Americans and is characterized by damage to

the nerves in the brain and spinal cord that becomes worse over time,

leading to spasticity or paralysis of muscles.

But his disease seems to have been put on hold, thanks to a new and

controversial stem cell therapy that he received at Northwestern Memorial

Hospital.

Over the last 20 years, the transplantation of bone marrow stem cells

revolutionized the treatment of leukemias and other cancers.

The revolution is gradually moving to autoimmune disorders such as multiple

sclerosis, lupus, rheumatoid arthritis and Crohn's disease. But with that

promise comes a cost: The stem cell therapy can be fatal, while MS rarely

is.

Stem cells, the master cells that make blood, are retrieved from a patient's

bloodstream before therapy and then returned to the same patient, a process

known as autologous transplantation.

Although stem cells are found in larger numbers in bone marrow, removal from

the bloodstream is easier, less costly and does not require general

anesthesia. When re-infused into the bloodstream, they migrate into the bone

marrow and--if the therapy is successful--produce a new immune system.

Such transplants demonstrate the regenerative behavior of stem cells--either

from a stranger or from oneself--and their power to heal. They provide most

of the hard evidence behind the stem cell revolution that has swept through

science and is being debated in Congress and in countries worldwide.

Now 25, Sears, of the South Side, is back studying psychology at Moraine

Valley Community College in Palos Hills. His symptoms have subsided. His

future looks much brighter.

" I can write with a pen again, " he said, ticking off the improvements. " The

hand tremors are much better. I can butter my own bread and eat soup, which

I couldn't do before. I can climb stairs again.

" Before, I couldn't walk a hundred feet. Now, I can walk for miles. "

Nobody knows what causes MS, but it seems triggered when the body becomes

allergic to itself and the misdirected immune system attacks the central

nervous system--specifically, the myelin sheaths, the thin layers of fatty

cells that wrap around and insulate nerve fibers of the brain and spinal

cord.

Repeated attacks bring about a loss of the protective coating of myelin,

which halts nerve cells from communicating much the way that frayed

electrical wires short out and stop carrying current. MS is a crippler, not

usually a killer, but the progression of the disease cannot be predicted and

depends on the individual.

Northwestern Memorial has pioneered stem cell transplants for this and other

devastating neurological disorders. Dr. K. Burt, the hospital's

director of immunotherapy, performed the first procedure in the U.S. in

1997. Based on the program's success so far, the National Institute of

Allergy and Infectious Diseases awarded the hospital a $9.2 million contract

for further research on stem cell transplants for autoimmune diseases.

Sears received his transplant in January 2001. After doctors removed stem

cells from his own blood, they killed his immune system, which had turned

into a renegade, and then returned the healthy bloodmaking cells to his

body.

The cells set up shop and built a new immune system that didn't attack his

myelin.

Sears was hospitalized for three weeks. The transplant cost $85,000, and

Medicaid paid. If resetting the young man's immune system stops further

damage from MS, the long-term costs of the disease would make stem cell

transplants a bargain.

Sears' initial diagnosis, frightening as it was, was confounded even more

because specialists could not predict what would happen to him.

Symptoms of MS may be mild--numbness or weakness in the limbs, blurred

vision, clumsiness--or severe, such as paralysis, loss of intellect,

blindness. About 70 percent of patients experience problems sporadically

over several years--the " relapsing-remitting " form of the disease--but in

others it progresses rapidly, leaving them bedridden, confined to a

wheelchair or dead within 10 years.

Faced with such uncertainties, the MS research community is conservative and

suspicious of any new therapy.

Studies of stem cell transplants for MS have involved small groups of

severely disabled patients at research hospitals, and the evidence is

mounting that the new treatment is safe. Trials are getting under way to

test its efficacy and compare that to accepted treatments.

Researchers, like Northwestern's Burt, worry about raising false hopes.

" We recently completed our study of 29 patients, and in most of them the

tests suggested no further loss of myelin, " he said. " We seem to be holding

the disease in check.

" On the other hand, despite the transplant, some of our more severely

disabled patients continued to deteriorate. We may have stopped the further

loss of myelin, but for them it didn't seem to matter.

" I think when people reach that point, there's something else going on. MS

may actually be two diseases. When too many nerve cells have been destroyed,

our stem cell therapy is like closing the barn door after the horse has

left. "

Doing the transplant earlier, though, brings a formidable ethical problem.

" We want to do this in people who are having acute attacks, before the

long-term damage can accumulate, " Burt said. " But this is a very dramatic,

potential life-threatening therapy. And we'd be doing it on patients who

otherwise might do well on ordinary treatment.

" Bone marrow transplants are ethical in cancer, which is a fatal disease.

But MS rarely is fatal. So the ethics here are really tricky. "

The Northwestern Memorial results fall in line with those reported by other

institutions, where as many as 85 percent of transplanted MS patients seem

to be doing better.

" Preventing people with MS from becoming disabled--that's the goal, " Burt

said. " No other therapy has done that. But it's still too early to say if

stem cell transplants can prevent disability. "

One of the first patients in the world to have the transplant before she was

physically disabled was Air Force Capt. Deb Strand, a critical care nurse,

who lives near Olympia, Wash.

" Because of MS, my life went to hell in a year and a half, " she said. " I

lost my job, my career, my nursing license--I had cognitive problems,

started to stutter and couldn't remember patients. My IQ dropped from 130 in

college to 87. I had to retire from the military. "

She did research on the Internet, discovered Burt and came to Northwestern

Memorial in July 2000. Her transplant was on Aug. 11-- " that's when I

celebrate my birthday, " she said. " That's the day my new life began. "

She still has problems, she admits.

" But nothing has progressed. Nothing has gotten worse. The transplant is not

a cure-all; it's not like my MS has gone away. I still have short-term

memory problems, but I can cope with them.

" I have stability in my life. I'm not in limbo-land any longer. "

Doctors have known for 50 years that suppressing the immune system can slow

the progression of MS, but the tradeoff could be fatal. Without a working

immune system the body has nothing to fend off deadly bacteria or viruses.

The stem cell procedure has an unacceptable mortality rate--between 5 and 10

percent. But the rate in healthier patients has yet to be determined.

" It's in those people we want to reset the equilibrium, " Burt said.

And Sears, for one, couldn't agree more.

" The doctors told me not to count on the transplant reversing the disease, "

he said. " But I'm really glad I did it. So far, I love it. I absolutely love

it. "

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