Cord Blood Stem Cells Pave Road to Recovery for Leukemia Patient
By Warren King, The Seattle Times, July 11, 2007
Tyler thought leukemia had gotten the best of him when no suitable bone-marrow donor worldwide could be found. He thought his days were numbered when doctors told him the news last winter.
He wondered how his friends would spend their lives. He had studies in Japan for a year, and his dream of a return trip was now out of the question. Slowly fading to black, were hid goals of becoming a filmmaker.
"I was pretty depressed. I thought a lot about what I had been able to do in life," said Tyler, 22, of Spokane.
But the umbilical cord blood stem cells from 2 babies were compatible and could help cure him. Tyler felt like he was given a second chance.
Capable of replacing the cancerous cells of leukemia by producing new healthy blood cells; the stem cells a more commonly taken from bone marrow as opposed to cord blood.
Tyler learned that at the Fred Hutchinson Cancer Research Center, his odds could be further improved by new stem-cell technology.
"It was pretty amazing. I thought, 'How did you find that?' " said Colosimo, now recovering from a cord-blood stem-cell transplant he received May 24.
Finding a biologically matched bone-marrow donor is not the easiest, and Tyler was one of nearly 13,000 people each year who have difficulty finding a match. Despite the 9 million people on donor registries, other family members, and even sibling; there is no help.
Since the vast majority of bone-marrow donors are Caucasian, minorities are disproportionately affected because stem-cell matches are linked to race.
For Tyler, surviving acute myelogenous leukemia would have been unlikely without the suitable cells. Certain kinds of anemia, other types of leukemia, and other potentially fatal diseases can be treated using stem cell transplants.
For children who can't find an optimal match, stem cells from umbilical cords work well. These cells have been around for almost 20 years.
The donated cells are transplanted and begin producing new cells, but the patient's blood cells -- including the diseased ones -- must first be killed off by chemotherapy and radiation prior to transplant.
In contrast to bone marrow which requires a close match, cord-blood stem cells do not need to be as compatible. Additionally, 45 cord-blood banks around the world already have blood available for use.
Since children are smaller in size, they need far fewer cells than adults to quickly replace those killed off by the pre-treatment protocol. To protect against disease and infection, this includes white cells.
While the cells reproduce and build a new immune system adult must be closely monitored since they are vulnerable to potentially fatal infections for about 25 days after such a transplant.
However, there now may be a way around the problem thanks to the efforts of Dr. Colleen Delaney, a Hutchinson Center oncologist and researcher. Quick reproduction of the cord-blood stem cells is stimulated by placing them in a special culture prior to transplant.
The technique draws on the research of Dr. Irwin Bernstein, a Hutchinson Center pioneer in learning how stem cells develop.
In only 17 days, Delaney has expanded the number of blood stem cells 150-fold. The amount of time a patient is most vulnerable to infection is subsequently reduced to about 15 days. Only yielding about a fourfold increase in cells, scientists at other institutions have attempted similar techniques without so much success.
"This can open up a whole new donor pool for people who can't find donors," Delaney said.
The treatment is experimental and Tyler is only the third patient to experience it. A 30-year-old woman and a 42-year old San Francisco man both fared well after transplant. The man is battling a viral infection at the present time a year after his treatment, but the woman is now healthy six months following her initial treatment.
Safety of treatment is the primary concern at this point, and it is only in the first phase of research. Over the next two years, this particular phase will involve approximately 12 more patients. Other medical centers will become involved with more trials with more patients if this initial phase proves promising.
"It's very early in the research now," Delaney said. "We have to have more patients to see where this is going."
Since he was diagnosed in November, Tyler has had a rough six months like all leukemia patients do.
Tyler was physically active in various sports including rowing and karate. This made his early symptoms; the terrific aching in his legs, back, and wrists, quite perplexing. He developed difficulty breathing and fever while his test results were pending. Then two days after Thanksgiving, he was diagnosed with leukemia.
To prepare for his transplant, Tyler began his chemotherapy soon so he could put his leukemia into remission. A suitable bone-marrow match could not be found after months of searching. Compatibility issues arose even when checking his brother for a match.
Cord-blood was a welcome alternative, especially with their network of banks. Looking for the very best donors became the luxury of the doctors since patients have a 95% chance of finding a suitable donor with cord blood.
He needed a double dose of stem cells and when two matching donors were found, Tyler was ready.
"I got pretty excited, when Dr. Delaney told me," he said.
In preparation for the transplant, Tyler decided to go through the harsh treatment.
To make room for the new, healthy cells, total body radiation and chemotherapy were used to destroy all his blood cells as well as the cancerous ones. The process left Tyler exhausted and nauseas.
Dripping into Tyler's body was a deep red colored solution of stem cells, as Tyler's parents, Lynn and Tom, and brother Ben gathered in his hospital room on May 24th; the day of the transplant.
"We really looked forward to that Day Zero, as they called it," said Lynn. "Now we count the days since the transplant."
Headaches and diarrhea racked his body for two weeks and he developed terrible fevers and mouth sores. These were part of the rough days Tyler had to endure after the transplant.
He was able to retreat to a South Lake Union apartment near the Seattle Cancer Care Alliance (where he received outpatient treatment and tests) and Hutchinson Center on June 14th. He will continue his three months of initial recovery there.
Provided that everything goes well, he should be able to recover completely in about a year, but he is exhausted right now. In 2008, he hopes to resume his studies at the University of Idaho, where he would be a senior.
His dreams of becoming a filmmaker have returned, and traveling and perhaps even working in Japan are among his resurrected goals.
"So far, I'm happy with the treatment," he said. "It seems like it's working."
|