The Cord Blood Cure

StemCellsChina.com

Donnerstag, 28. September 2006 um 00:29 Uhr

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Source: Scienceline

By Kristina Fiore

Rich in stem cells, umbilical cord blood has become a viable alternative to bone marrow transplantation in adults.

It was hot that summer in 1996, Gayle Serls recalled, so she had blamed her constant fatigue on a sweltering Southern July. It wasn't until August that the pain and symptoms-the nausea, the fainting, the vomiting-became unbearable. At that point, the athletic Durham, N.C., native who exercised frequently and ate healthfully became a patient at Duke University Medical Center. She was diagnosed with acute lymphocytic leukemia, a fast-growing
cancer of the white blood cells.

Serls suffered through weeks of chemotherapy, and was able to beat the disease into remission within a month. But that wasn't the end of her treatment. Follow-up tests revealed Serls's leukemia was a rare kind that would not stay in remission. That's when her doctor started talking about a bone marrow transplant.

Since Duke didn't have an adult bone marrow transplant program at the time, Serls was sent to Johns Hopkins University instead. There, doctors told the 45-year-old that she was too old for a regular bone marrow transplant. They could perform an autologous bone marrow transplant instead, which would "clean up" her own cells and put them back into her body.

But before she could begin her treatment at Hopkins, Serls relapsed, literally on the medical center's doorstep. She couldn't go through with the bone marrow treatment, and was immediately flown back to Duke for chemo again.

Just days before her daughter's severe relapse, Serls's mother watched a television news report on a new leukemia treatment. It was called an umbilical cord blood transplant, and it was very experimental, with a low survival rate. Serls didn't care-she was desperate.

Though it wasn't common during Serls's treatment 10 years ago, adult cord blood transplantation has now gained popularity as an alternative to bone marrow transplantation in diseases such as leukemia and lymphoma. In 2005, there were more than 1,400 cord blood transplantations in adults, according to NETCORD, an international network that coordinates umbilical cord blood banks. This year, journals have published reviews of the state-of-the-art of the procedure. Their consensus: cord blood transplantation in adults is a viable alternative to bone marrow transplant, is often easier to obtain and
enables more efficient donor-recipient coordination.

This wasn't the case in 1996, when Serls was dying from acute lymphocytic leukemia. The procedure was largely experimental, and though she didn't have much to lose, she also didn't have much of a choice.

Finding hope in an experimental procedure

Cord blood is the blood leftover in a baby's umbilical cord immediately after birth. It is usually thrown away. Lately, its collection has gained popularity because of the value of the stem cells found in the blood. These are cells in a state of "identity crisis," which have not morphed into specific cell types (such as liver or heart tissue), giving them excellent potential to adapt to another person's body. In patients with leukemia, a
cancer that prevents the body from creating healthy blood cells, transplanted stem cells can become the blood-making cells the body lacks.

The first recipient of cord blood transplantation was a six-year-old boy suffering from Fanconi anemia. His 1988 procedure was a success, and cord blood transplantation has since become a popular treatment for childhood leukemias.

Over the years, researchers have also been experimenting with the use of cord blood transplantation in adults. Claudio Brunstein, a researcher at the University of Minnesota Cancer Center's cord blood transplantation program, focuses on using cord blood to treat adult leukemias. He was an author of the June 2006 cord blood transplantation review published in the journal Bone Marrow Transplantation, a sister publication of the journal Nature.

In the article, he notes some of the limitations of the treatment-such as survival rates and the amount of cord blood needed to treat an adult patient-but also notes its many benefits, which have increased over the years.

At the time Serls underwent treatment, many kinks in the procedure hadn't yet been worked out. As soon as her mother told her about cord blood transplantation, Serls tracked down Mary Laughlin, then an assistant professor of medicine at Duke University, who was conducting a clinical trial on cord blood transplants in adults. Laughlin was a pioneer; the
treatment had been common only in children at the time.

Serls became the third of Laughlin's adult cord blood transplant patients.

"She came to see me in my [hospital] room, and I wanted to know, 'could I be a candidate?'" Serls recalled. "But she was talking to me like, 'OK, we aregoing to do this.'"

Laughlin's expertise is in the field of innovative leukemia therapies. She began testing cord blood as a stem cell source because many of her patients could not find a matching marrow donor in time to treat their disease. She was tired of facing patients with life-threatening leukemias and being forced to advise them to just go home.

"Testing cord blood stem cell transplant in adults . allowed me an opportunity to offer a potentially life-saving therapy for my adult leukemia patients," said Laughlin, who is now a professor of medicine and pathology at Case Western Reserve University's School of Medicine.

"I had hope again," Serls said about meeting Laughlin and trying the experimental therapy. "She explained that it was probably only a 10 to 20 percent chance of survival. But when you're told there's NO hope, then 10 to 20 percent might as well have been 100 percent as far as I was concerned."

The first step was to find Serls a matching donor.

Easier matchmaking

The biggest advantage cord blood transplantation has over bone marrow transplantation is that it is much easier to match patient and donor, Brunstein said. While bone marrow requires an exact match, cord blood does not. Optimally, the cord blood donor and recipient should match six out of six blood antigens, in the same way that a blood transfusion must be matched by type. However, the transplant can be successful with as few as four
matching antigens.

Because these requirements are less restrictive, Brunstein said, it is of ten easier to find a match. At the University of Minnesota, matches have often been made within one day-a significant advantage over bone marrow transplantation, which can take three to four months, according to Brunstein's review.

"Such rapid availability can be particularly useful for patients with high-risk malignancy or rapidly progressive non-malignant diseases," the review states.

This is especially good news for minority patients because there aren't many minority donors on the national bone marrow donation list.

It was also good news for Serls. She found a four out of six antigen match-the lowest number of matching antigens acceptable for the transplantation. Her only worry, then, was graft-versus-host-disease, a condition in which the transplant recipient's T-cells attack new tissue they perceive as foreign.

Brunstein said, however, that GVHD is less common than expected considering that most cord blood transplants are not fully matched.

"We believe it is because the immune cells in [cord blood transplantation] are naive and less prone to attack the recipient," he said.

Serls analyzed the risks: she had an average donor match and a chance of graft-versus-host-disease. Those risks looked better than her other alternative: death.

Policymakers focus on cord blood

Kristine Gebbie, director of the Center for Health Policy at Columbia University, had heard about cord blood transplantation but didn't know much about it when she was selected to head the Congressional committee investigating cord blood banking in 2004.

The committee's goal, Gebbie said, was not to establish if cord blood was a good treatment as well as a stem cell source-that was a given. Instead, the committee worked for eight months, hiring economic professionals, researchers and other advisors, to come up with a system of accreditation and standards for cord blood banks.

By April 2005, Gebbie's committee had settled on recommendations for establishing a banking process and submitted them to Congress. The report concluded that a national center to coordinate the network of collection agencies needed to be set up.

"Public banking [of cord blood] needs to be more strongly coordinated through central process linking donors and stored blood with transplantation sites and transplants," she said. "Also, standards need to be enforced through accreditation."

Following the committee's report, the federal government realized the growing demand for cord blood transplants. In December 2005, President Bush signed into law the Stem Cell Therapeutic and Research Act, which set aside $10 million to get the cord blood center up and running.

The legislation also mandated the need for the collection of 150,000 units of donated cord blood to stock the new center. Currently, there are 14 public cord blood centers, which communicate via an international network foundation called NETCORD-not a government-sponsored registry.

Two main competitors-New York Blood Center and National Marrow Donor Program-are in the running for control of the national registry. The federal government is still in the request-for-proposal phase for the center's creation, but the Health Resources and Services Administration under the U.S. Department of Health and Human Services has set goals for collecting the requested number of units.

According to David Bowman, spokesperson for HRSA, the agency will spend $9 million in 2006 on 6,900 units of cord blood, followed by another $9 million worth in 2007. The agency, however, did not request funds for 2007, and is using excess money from fiscal years 2004 to 2006 to purchase the units.

A 'tiny bag' of 'important cells'

If it was up to Gayle Serls, cord blood would receive all the funding necessary to make it a popular and affordable treatment. Ten years ago, her treatment cost $250,000, but costs much more now, she said.

Even though her insurance paid for almost all of the procedure, Serls said the price didn't matter. She was going to have the treatment, no matter what.

Two weeks after she began seeing Laughlin, Serls had her donor in place and was ready for the procedure. She was nervous, but she knew a cord blood transplant would be her best hope.

It was May 1997, and during that day at the hospital, Serls remembers being hooked up a pint-sized bag-"a tiny bag full of very important cells," she said-that would hopefully save her life.

The procedure was like any blood transfusion, she said. She was conscious the entire time, watching the liquid enter her veins, and hoping her body would accept it. Though she can't remember exactly how long it took, she knows the transplant was quick. But as she was wheeled back to her hospital room, waiting for her body's reaction seemed like an eternity.

All she could do was wait-wait for new cells to grow. Wait to see if she would develop GVHD. Wait to see if she would live.

Serls recalls being tired all the time during the following weeks as she lay in her hospital room. She couldn't eat, since her stomach couldn't hold food down.

A few weeks after the transplant, Serls did develop GVHD.

Luckily, she says, it was so minor that doctors were able to treat it.

After that, things started looking up. By mid-July, about nine weeks after her treatment, Serls was able to go home. Eating was still a task, and fatigue was a plague. But slowly, she healed.

It is now 10 years since her treatment, and Serls couldn't be happier with the choice she made. Though she hasn't felt as healthy as she did when she was young and active before the disease, she says she's doing well. She gets tired more easily, but that's her only complaint.

Serls believes so strongly in the power of adult cord blood transplantation that she now works as a cord blood unit coordinator in Duke University Medical Center's Pediatric Blood and Marrow Transplant program. Despite its title, Serls said, adult patients were frequently seen at the facility. Duke now has an Adult Bone Marrow and Stem Cell Transplant Program.

Sometimes Serls will comfort patients going in for the transplant, sharing her own story of survival.

"I'm one of the longest-surviving adults who have had the transplant in the world," she tells patients enthusiastically. "The longer I live from that moment, the more it means to me to have had that opportunity. It was just so serendipitous."

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